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Class 12 • Physics
AC fundamentals
Chapter-7
506 Questions
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87 Easy412 Medium7 Hard
Practice Questions
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1
MediumAiims
A transformer with turns ratio $\frac{N_1}{N_2}=\frac{50}{1} is connected to a 120 \mathrm{~V} AC supply. If primary and secondary circuit resistances are 1.5 \mathrm{~k} \Omega and 1 \Omega$ respectively, then find out power of output.
Options:
A) 5.76 W
B) 11.4 W
C) 2.89 W
D) 7.56 W
2
MediumAiims
If maximum energy is stored in a capacitor at t = 0, then find the time after which current in the circuit will be maximum.
Options:
A) \frac{\pi}{2} \mathrm{~ms}
B) \frac{\pi}{4} \mathrm{~ms}
C) \pi \mathrm{~ms}
D) 2 \mathrm{~ms}
3
MediumAiims
In a $L C R series circuit source voltage is 120 \mathrm{~V} and voltage in inductor 50 \mathrm{~V} and resistance is 40 \mathrm{~V}$, then determine voltage in the capacitor
Options:
A) V_C=10(5-8 \sqrt{2})
B) V_C=10(5+8 \sqrt{2})
C) V_C=20(5+8 \sqrt{2})
D) V_C=10(5+7 \sqrt{2})
4
MediumAiims
In a series R-C circuit shown in figure, the applied voltage is 10 V and the voltage across capacitor is found to be 8V. Then, the voltage across R and the phase difference between current and the applied voltage will respectively be
Options:
A) 6 \mathrm{~V}, \tan ^{-1}\left(\frac{4}{3}\right)
B) 3 V, \tan ^{-1}\left(\frac{3}{4}\right)
C) 6 \mathrm{~V}, \tan ^{-1}\left(\frac{5}{3}\right)
D) None of these
5
MediumAiims
An ideal coil of $10 \mathrm{~H} is connected in series with a resistance of 5 \Omega and a battery of 5 \mathrm{~V}. After 2 \mathrm{~s}$, after the connection is made, the current flowing (in ampere) in the circuit is
Options:
A) (1-e)
B) e
C) e^{-1}
D) \left(1-e^{-1}\right)
6
MediumAiims
In a circuit $L, C and R are connected in series with an alternating voltage source of frequency f. The current leads the voltage by 45^{\circ}. The value of C$ is
Options:
A) \frac{1}{2 \pi f(2 \pi f L+R)}
B) \frac{1}{\pi f(2 \pi f L+R)}
C) \frac{1}{2 \pi f(2 \pi f L-R)}
D) \frac{1}{\pi f(2 \pi f L-R)}
7
MediumAiims
A series R-C circuit is connected to AC voltage source. Consider two cases; (A) When C is without a dielectric medium and (B) When C is filled with dielectric of constant 4. The current I$_R through the resistor and voltage V_C$ across the capacitor are compared in two cases.
Options:
A) I_R^A> I_R^B
B) I_R^A< I_R^B
C) V_C^A< V_C^B
D) None of these
8
MediumAiims
Assertion : The average value of alternating emf is $63.39 \% of the peak value. Reason : The rms value of alternating emf is 70.72 \%$ of peak value.
Options:
A) Both assertion and reason are true and reason is the correct explanation of assertion
B) Both assertion and reason are true but reason is not the correct explanation of assertion
C) Assertion is true but reason is false
D) Both assertion and reason are false.
9
MediumBITSAT2023
A resistance $R and inductance L and a capacitor C all are connected in series with an \mathrm{AC} supply. The resistance of R is 24 \mathrm{~ohm} and for a given frequency, the inductive reactance of L is 36 ohm and capacitive reactance of C is 24 \mathrm{~ohm}. If the current in the circuit is 5 \mathrm{~amp}. Find the potential difference across R, L and C$.
Options:
A) 140,140,120 \mathrm{~V}
B) 80,120,120 \mathrm{~V}
C) 140,140,120 \mathrm{~V}
D) 120,180,120 \mathrm{~V}
10
MediumBITSAT2023
A direct current of $10 \mathrm{~A} is superimposed on an alternating current i=10 \sin \omega t$ flowing through the wire. The effective value of the resulting current will be.
Options:
A) (15 / 2) \mathrm{A}
B) 5 \sqrt{6} \mathrm{~A}
C) 5 \sqrt{5} \mathrm{~A}
D) 15 \mathrm{~A}
11
MediumBITSAT2022
A direct current of 6 A is superimposed on an alternating current I = 10 sin $\omega$t flowing through a wire. The effective value of the resulting current will be
Options:
A) 5$\sqrt2
B) 5$\sqrt3
C) 9.27
D) 8.37
12
MediumBITSAT2022
In the circuit shown in the figure, the AC source gives a voltage V = 20 cos (2000t) neglecting source resistance, the voltmeter and ammeter reading will be
Options:
A) 0 V, 0.47 A
B) 2.82 V, 1.41 A
C) 1.41 V, 0.47 A
D) 1.5 V, 8.37 A
13
MediumBITSAT2021
The phasor diagram of a load represents which circuit?
Options:
A) Purely capacitive
B) Purely inductive
C) R-L-C circuit with XL more than XC
D) R-L-C circuit with XL less than XC
14
MediumBITSAT2020
Three solenoid coils of same dimensions, same number of turns and same number of layers of windings are taken. Coil 1 has inductance L1 wounded by Mn wire of resistance 6 $\Omegam-$1, coil 2 with inductance L2 wounded by similar wire but in reverse direction in each layer. Coil 3 with inductance L3 wounded by a superconducting wire. The relation between their self inductances will be
Options:
A) L1 = L2, L3 = 0
B) L1 = L2 = L3
C) L1 = L3, L2 = 0
D) L1 > L2 > L3
15
MediumBITSAT2020
In the circuit shown in figure, the AC source has angular frequency $\omega = 2000 rad s-$1. The amplitude of the current will be nearest to
Options:
A) 2.85 A
B) 3 A
C) 0.5 A
D) 3.625 A
16
MediumCOMEDK2025
A power transmission line feeds input power at 2200 V to a step-down transformer with its primary windings having 2000 turns. The output power is delivered at 220 V by the transformer. If the current in the primary of the transformer is 2 A and its efficiency is 80 \%, the output current would be:
Options:
A) 32 A
B) 8 A
C) 16 A
D) 4 A
17
MediumCOMEDK2025
A series LCR circuit having \mathrm{R}=44 \Omega, \mathrm{~L}=2 \mathrm{H} and \mathrm{C}=25 \mu \mathrm{~F} is connected to a variable frequency of 220 V . What is the average power transferred to the circuit in one complete cycle if the frequency of supply equals the natural frequency of the circuit?
Options:
A) 2.1 kW
B) 4.2 kW
C) 1.1 kW
D) 1.2 kW
18
MediumCOMEDK2025
In a pure inductive circuit, a sinusoidal voltage V(t)=200 \sin 250 t is applied to a pure inductance of \mathrm{L}=0.02 \mathrm{H}. The current through the coil is:
Options:
A) 40 \sin \left[250 t-\frac{\pi}{2}\right]
B) 40 \cos \left[250 t-\frac{\pi}{2}\right]
C) 40 \sin \left[250 t+\frac{\pi}{2}\right]
D) 40 \cos \left[250 t+\frac{\pi}{2}\right]
19
MediumCOMEDK2025
The instantaneous values of alternating current and voltages in a circuit are \mathrm{I}=\frac{3}{\sqrt{2}} \sin (200 \pi t) ampere and \mathrm{V}=\frac{3}{\sqrt{2}} \sin \left(200 \pi t+\frac{\pi}{6}\right) volt. What is the average power consumed in the circuit in watt ?
Options:
A) \frac{\sqrt{3}}{8}
B) \frac{6 \sqrt{3}}{8}
C) \frac{8 \sqrt{2}}{9}
D) \frac{9 \sqrt{3}}{8}
20
MediumCOMEDK2025
The ratio of the number of turns of the primary coil to the secondary coil of an ideal transformer is 5: 1. The primary is connected to 220 V supply. What is the output power of the transformer if the output resistance is 11 \Omega ?
Options:
A) 1760 W
B) 1100 W
C) 176 W
D) 100 W
21
MediumCOMEDK2025
In which of the following circuit do we find the current and voltage in phase?
Options:
A) A purely resistive circuit
B) A circuit in which an inductor and a capacitor are in series.
C) A purely Inductive circuit
D) A purely capacitive circuit
22
MediumCOMEDK2025
What should be the value of the inductance of the coil which is to be connected to 220 V , 50 Hz supply so that maximum current of 3 \sqrt{2} A flows through the circuit ?
Options:
A) L=\left(\frac{22}{15}\right) H
B) L=\left(\frac{15}{11 \pi}\right) H
C) L=\left(\frac{11}{15 \pi}\right) H
D) L=\left(\frac{22}{15} \sqrt{2}\right) H
23
MediumCOMEDK2025
An ideal inductor is connected across a capacitor. Oscillations of energy K are set up in the circuit. The capacitor plates are slowly drawn apart such that the frequency of oscillations is quadrupled. The work done in the process is
Options:
A) 15K
B) 13K
C) zero
D) 2K
24
MediumCOMEDK2025
If R and L denote resistance and inductance of a material, then the dimension of L R will be:
Options:
A) M^2 L^4 T^{-5} A^{-4}
B) M L T A^{-1}
C) M^0 L^0 T^0 A^0
D) M^{-1} L^4 T A^{-3}
25
MediumCOMEDK2025
A bulb of resistance 280 Ohm is supplied with a voltage \mathrm{V}=400 \sin \pi \mathrm{t}. The peak current is
Options:
A) 2.22 A
B) 2.02 A
C) 1.11 A
D) 1.43 A
26
MediumCOMEDK2025
An LCR series ac circuit is at resonance with 10 V each across \mathrm{L}, \mathrm{C} and R . If the resistance is halved, the respective voltage across R, C and L are
Options:
A) 5 \mathrm{~V}, 10 \mathrm{~V}, 10 \mathrm{~V}
B) 10 \mathrm{~V}, 5 \mathrm{~V}, 5 \mathrm{~V}
C) 5 \mathrm{~V}, 5 \mathrm{~V}, 5 \mathrm{~V}
D) 10 \mathrm{~V}, 20 \mathrm{~V}, 20 \mathrm{~V}
27
MediumCOMEDK2024
When an A.C. source is connected to a inductive circuit,
Options:
A) voltage and current are in same phase.
B) voltage is ahead of current in phase.
C) the phase between voltage and current depends upon the value of inductance
D) voltage lags behind current in phase.
28
MediumCOMEDK2024
In the $\mathrm{A} . \mathrm{C}. circuit given below, voltmeters \mathrm{V}_1 and \mathrm{V}_2 read 100 \mathrm{~V} each. Find the reading of the voltmeter \mathrm{V}_3 and the ammeter \mathrm{A}$.
Options:
A) 220 V, 2 A
B) 110 V, 2 A
C) 110 V, 4 A
D) 220 V, 1 A
29
MediumCOMEDK2024
A transformer has 400 turns in its primary winding and 800 turns in its secondary winding. The primary voltage is $20 \mathrm{~V}$ and the load in the secondary is 4 ohm. The current in the primary, assuming it to be an ideal transformer, is
Options:
A) 40 A
B) 20 A
C) 4 A
D) 2 A
30
MediumCOMEDK2024
A group of devices having a total power rating of 500 watt is supplied by an $\mathrm{AC} voltage E=200 \sin \left(3.14 t+\frac{\pi}{4}\right)$. Then the r.m.s. value of the circuit current is
Options:
A) 500 A
B) 1 A
C) 200 A
D) 5 A
31
MediumCOMEDK2024
An AC voltage source of variable angular frequency $\omega and fixed amplitude \mathrm{V}_0 is connected in series with a capacitance \mathrm{C} and an electric bulb of resistance \mathrm{R} (inductance zero). When \omega$ is decreased
Options:
A) the bulb switches off
B) total impedance of the circuit is unchanged
C) the bulb glows brighter
D) the bulb glows dimmer
32
MediumCOMEDK2024
A transformer which steps down $330 \mathrm{~V} to 33 \mathrm{~V} is to operate a device having impedance 110 \Omega$. The current drawn by the primary coil of the transformer is :
Options:
A) 0.3 A
B) 0.03 A
C) 3 A
D) 1.5 A
33
MediumCOMEDK2024
A coil of inductance $1 \mathrm{H} and resistance 100 \Omega is connected to an alternating current source of frequency \frac{50}{\pi} \mathrm{~Hz}$. What will be the phase difference between the current and voltage?
Options:
A) 90$^\circ
B) 30$^\circ
C) 60$^\circ
D) 45$^\circ
34
MediumCOMEDK2024
A coil offers a resistance of $20 \mathrm{~ohm}$ for a direct current. If we send an alternating current through the same coil, the resistance offered by the coil to the alternating current will be :
Options:
A) 0 \Omega
B) Greater than $20 \Omega
C) Less than $20 \Omega
D) 20 \Omega
35
MediumCOMEDK2024
The capacitance of a parallel plate capacitor is $400 \mathrm{~pF}. It is connected to an ac source of 100 \mathrm{~V} having an angular frequency 100 \mathrm{~rad~s}^{-1}. If the rms value of the current is 4 \mu \mathrm{A}$, the displacement current is:
Options:
A) 4 \times 10^{-2} \mu \mathrm{A}
B) 0.4 $\mu$A
C) 4 $\mu$A
D) 4 A
36
MediumCOMEDK2023
The instantaneous values of alternating current and voltages in a circuit given as $\begin{aligned} & i=\frac{1}{\sqrt{2}} \sin (100 \pi t) \mathrm{amp} \\ & e=\frac{1}{\sqrt{2}} \sin (100 \pi t+\pi / 3) \text { volt } \end{aligned}$ The average power (in watts) consumed in the circuit is
Options:
A) \frac{1}{4}
B) \frac{\sqrt{3}}{4}
C) \frac{1}{2}
D) \frac{1}{8}
37
MediumCOMEDK2023
In the series L-C-R circuit shown, the impedance is
Options:
A) 200$\Omega
B) 100$\Omega
C) 300$\Omega
D) 500$\Omega
38
MediumCOMEDK2023
In the case of an inductor
Options:
A) voltage lags the current by $\pi / 2
B) voltage leads the current by $\pi / 2
C) voltage leads the current by $\pi / 3
D) voltage leads the current by $\pi / 4
39
MediumCOMEDK2023
In an electrical circuit $R, L, C and \mathrm{AC} voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and the current in the circuit is \pi / 3. If instead C is removed from the circuit, the phase difference is again \pi / 3$. The power factor of the circuit is
Options:
A) 1 / 2
B) 1 \sqrt{2}
C) 1
D) \frac{\sqrt{3}}{2}
40
MediumCOMEDK2023
220 \mathrm{~V} ac is more dangerous than 220 \mathrm{~V}$ dc Why?
Options:
A) The peak value of ac is greater than the given value of dc
B) Shock received from ac is always repulsive
C) The frequency of ac is more than that of dc
D) The speed of ac is more than that of $\mathrm{dc}
41
MediumCOMEDK2023
What should be the inductance of an inductor connected to $200 \mathrm{~V}, 50 \mathrm{~Hz} source so that the maximum current of \sqrt{2}$ A flows through it?
Options:
A) \frac{\sqrt{2}}{\pi} H
B) 2 \pi H
C) \frac{2}{\pi} \mathrm{H}
D) \frac{\pi}{2} H
42
MediumCOMEDK2022
During the phenomenon of resonance
Options:
A) the amplitude of oscillation becomes large
B) the frequency of oscillation becomes large
C) the time period of oscillation becomes large
D) All of the above
43
MediumCOMEDK2022
A DC ammeter and a hot wire ammeter are connected to a circuit in series. When a direct current is passed through circuit, the DC ammeter shows 6 A. When AC current flows through circuit, what is the average readings in DC ammeter and the AC ammeter, if DC and AC currents flows simultaneously through the circuit?
Options:
A) DC = 6 A, AC = 10 A
B) DC = 3 A, AC = 5 A
C) DC = 5 A, AC = 8 A
D) DC = 2 A, AC = 3 A
44
MediumCOMEDK2022
A series L-C-R circuit is connected to an AC source of 220 V and 50 Hz shown in figure. If the readings of the three voltmeters $V_1,V_2 and V_3$ are 65 V, 415 V and 204 V respectively, the value of inductance and capacitance will be
Options:
A) 2.0 H, 5 $\mu$F
B) 1.0 H, 5 $\mu$F
C) 4.0 H, 6 $\mu$F
D) 1.0 H, 2 $\mu$F
45
MediumCOMEDK2022
An alternating voltage = 200 $\sin 100t is applied to a series combination of R=30\Omega$ and an inductor of 400 mH. The power factor of the circuit is,
Options:
A) 0.01
B) 0.6
C) 0.05
D) 0.042
46
MediumCOMEDK2022
The AC voltage across a resistance can be measured using a
Options:
A) hot wire voltmeter
B) moving coil galvanometer
C) potential coil galvanometer
D) moving magnetic galvanometer
47
MediumCOMEDK2021
The formula of capacitative reactance is
Options:
A) 2\pi fC
B) \frac{fC}{2\pi}
C) \frac{C}{2\pi f}
D) \frac{1}{2\pi fC}
48
MediumCOMEDK2021
For the same resonant frequency, if L is changed from L to ${L \over 3}$, then capacitance should change from C to
Options:
A) {C \over 3}
B) 3C
C) {2 \over 3}C
D) 2C
49
MediumCOMEDK2021
What should be the value of self-inductance of an inductor that should be connected to 220 V 50 Hz supply, so that a maximum current of 0.9 A flows through it?
Options:
A) 11 H
B) 2 H
C) 1.1 H
D) 5 H
50
MediumCOMEDK2021
If impedance is $\sqrt3$ times of resistance, then find phase difference.
Options:
A) Zero
B) 30$^\circ
C) 60$^\circ
D) Data is incomplete
51
MediumCOMEDK2020
For a series L-C-R circuit at resonance, which statement is not true?
Options:
A) Wattless current is zero.
B) Power factor is zero.
C) Peak energy stored by a capacitor = peak energy stored by an inductor.
D) Average power = apparent power.
52
HardJee Advance2025
A circuit with an electrical load having impedance Z is connected with an AC source as shown in the diagram. The source voltage varies in time as V(t)=300 \sin (400 t) \mathrm{V}, where t is time in s . List-I shows various options for the load. The possible currents i(t) in the circuit as a function of time are given in List-II. Choose the option that describes the correct match between the entries in List-I to those in ListII. List–I List–II (P) (1) (Q) (2) (R) (3) (S) (4) (5)
Options:
A) \mathrm{P} \rightarrow 3, \mathrm{Q} \rightarrow 5, \mathrm{R} \rightarrow 2, \mathrm{~S} \rightarrow 1
B) \mathrm{P} \rightarrow 1, \mathrm{Q} \rightarrow 5, \mathrm{R} \rightarrow 2, \mathrm{~S} \rightarrow 3
C) \mathrm{P} \rightarrow 3, \mathrm{Q} \rightarrow 4, \mathrm{R} \rightarrow 2, \mathrm{~S} \rightarrow 1
D) \mathrm{P} \rightarrow 1, \mathrm{Q} \rightarrow 4, \mathrm{R} \rightarrow 2, \mathrm{~S} \rightarrow 5
53
HardJee Advance2024
The circuit shown in the figure contains an inductor L, a capacitor C_0, a resistor R_0 and an ideal battery. The circuit also contains two keys \mathrm{K}_1 and \mathrm{K}_2. Initially, both the keys are open and there is no charge on the capacitor. At an instant, key \mathrm{K}_1 is closed and immediately after this the current in R_0 is found to be I_1. After a long time, the current attains a steady state value I_2. Thereafter, \mathrm{K}_2 is closed and simultaneously \mathrm{K}_1 is opened and the voltage across C_0 oscillates with amplitude V_0 and angular frequency \omega_0. Match the quantities mentioned in List-I with their values in List-II and choose the correct option. List-I List-II (P) The value of I_1 in Ampere is (1) 0 (Q) The value of I_2 in Ampere is (2) 2 (R) The value of \omega_0 in kilo-radians/s is (3) 4 (S) The value of V_0 in Volt is (4) 20 (5) 200
Options:
A) \mathrm{P} \rightarrow 1 ; \mathrm{Q} \rightarrow 3 ; \mathrm{R} \rightarrow 2 ; \mathrm{S} \rightarrow 5
B) \mathrm{P} \rightarrow 1 ; \mathrm{Q} \rightarrow 2 ; \mathrm{R} \rightarrow 3 ; \mathrm{S} \rightarrow 5
C) \mathrm{P} \rightarrow 1 ; \mathrm{Q} \rightarrow 3 ; \mathrm{R} \rightarrow 2 ; \mathrm{S} \rightarrow 4
D) \mathrm{P} \rightarrow 2 ; \mathrm{Q} \rightarrow 5 ; \mathrm{R} \rightarrow 3 ; \mathrm{S} \rightarrow 4
54
HardJee Advance2023
A series LCR circuit is connected to a 45 \sin (\omega t) Volt source. The resonant angular frequency of the circuit is 10^5 ~\mathrm{rad}~ \mathrm{s}^{-1} and current amplitude at resonance is I_0. When the angular frequency of the source is \omega=8 \times 10^4 ~\mathrm{rad} ~\mathrm{s}^{-1}, the current amplitude in the circuit is 0.05 I_0. If L=50 ~\mathrm{mH}, match each entry in List-I with an appropriate value from List-II and choose the correct option. List - I List - II (P) I_0 in \mathrm{mA} (1) 44.4 (Q) The quality factor of the circuit (2) 18 (R) The bandwidth of the circuit in \mathrm{rad}~ \mathrm{s}^{-1} (3) 400 (S) The peak power dissipated at resonance in Watt (4) 2250 (5) 500
Options:
A) P \rightarrow 2, Q \rightarrow 3, R \rightarrow 5, S \rightarrow 1
B) P \rightarrow 3, Q \rightarrow 1, R \rightarrow 4, S \rightarrow 2
C) P \rightarrow 4, Q \rightarrow 5, R \rightarrow 3, S \rightarrow 1
D) P \rightarrow 4, Q \rightarrow 2, R \rightarrow 1, S \rightarrow 5
55
EasyJee Advance2013
A thermal power plant produces electric power of 600 kW at 4000 V, which is to be transported to a place 20 km away from the power plant for consumers' usage. It can be transported either directly with a cable of large current carrying capacity or by using a combination of step-up and step-down transformers at the two ends. The drawback of the direct transmission is the large energy dissipation. In the method using transformers, the dissipation is much smaller. In this method, a step-up transformer is used at the plant side so that the current is reduced to a smaller value. At the consumers' end, a step-down transformer is used to supply power to the consumers at the specified lower voltage. It is reasonable to assume that the power cable is purely resistive and the transformers are ideal with power factor unity. All the currents and voltages mentioned are rms values.
Options:
A) 200 : 1
B) 150 : 1
C) 100 : 1
D) 50 : 1
56
EasyJee Advance2010
An AC voltage source of variable angular frequency $\omega and fixed amplitude V0 is connected in series with a capacitance C and an electric bulb of resistance R (inductance zero). When \omega$ is increased
Options:
A) the bulb glows dimmer.
B) the bulb glows brighter.
C) total impedance of the circuit is unchanged.
D) total impedance of the circuit increases.
57
HardJee Advance2010
You are given many resistances, capacitors and inductors. These are connected to a variable DC voltage source (the first two circuits) or an AC voltage source of 50 Hz frequency (the next three circuits) in different ways as shown in Column II. When a current I (steady state for DC or rms for AC) flows through the circuit, the corresponding voltage V_1 and V_2 (indicated in circuits) are related as shown in Column I. Match the two :
Options:
A) (A)→(R), (S), (T); (B)→(Q), (R), (S), (T); (C)→(P), (Q); (D)→(Q), (R), (S), (T)
B) (A)→(R), (S); (B)→(Q), (R), (S), (T); (C)→(P), (Q); (D)→(Q), (R), (T)
C) (A)→(R), (S), (T); (B)→(Q), (R), (S); (C)→(P), (Q); (D)→(Q), (R), (S)
D) (A)→(S), (T); (B)→(Q), (R), (S), (T); (C)→(P); (D)→(Q), (R), (S), (T)
58
MediumJee Advance2007
STATEMENT 1 A vertical iron rod has a coil of wire wound over it at the bottom end. An alternating current flows in the coil. The rod goes through a conducting ring as shown in the figure. The ring can float at a certain height above the coil. Because STATEMENT 2 In the above situation, a current is induced in the ring which interacts with the horizontal component of the magnetic field to produce an average force in the upward direction.
Options:
A) Statement-1 is True, Statement-2 is True; Statement-2 is a correct explanation for Statement-1.
B) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1.
C) Statement-1 is True, Statement-2 is False.
D) Statement-1 is False, Statement-2 is True.
59
MediumJee Advance2006
Match the following columns. Column I Column II (A) Dielectric ring uniformly charged. (P) Time independent electrostatic field out of system. (B) Dielectric ring uniformly charged rotating with angular velocity $\omega. (Q) Magnetic field. (C) Constant current in ring io (R) Induced electric field. (D) i=i_0\cos\omega t$ (S) Magnetic moment.
Options:
A) A $\to (P); B \to (Q, S); C \to (Q, S); D \to$ (Q, R, S)
B) A $\to (P); B \to (S); C \to (Q, S); D \to$ (R, S)
C) A $\to (P); B \to (Q); C \to (Q, S); D \to$ (S)
D) A $\to (P); B \to (S); C \to (Q); D \to$ (Q, R, S)
60
MediumJee Advance2006
The capacitor of capacitance C can be charged (with the help of a resistance R ) by a voltage source V , by closing switch \mathrm{S}_1 while keeping switch \mathrm{S}_2 open. The capacitor can be connected in series with an inductor L by closing switch \mathrm{S}_2 and opening \mathrm{S}_1.
Options:
A) after time interval \tau, charge on the capacitor is \frac{\mathrm{CV}}{2}.
B) after time interval 2 \tau, charge on the capacitor is \mathrm{CV}\left(1-e^{-2}\right).
C) the work done by the voltage source will be half of the heat dissipated when the capacitor is fully charged.
D) after time interval 2 \tau, charge on the capacitor is \mathrm{CV}\left(1-e^{-1}\right).
61
MediumJee Advance2006
The capacitor of capacitance C can be charged (with the help of a resistance R ) by a voltage source V , by closing switch \mathrm{S}_1 while keeping switch \mathrm{S}_2 open. The capacitor can be connected in series with an inductor L by closing switch \mathrm{S}_2 and opening \mathrm{S}_1.
Options:
A) at t=0, the energy stored in the circuit is purely in the form of magnetic energy.
B) at any time t>0, the current in the circuit is in the same direction.
C) at t>0, there is no exchange of energy between the inductor and the capacitor.
D) at any time t>0, the instantaneous current in the circuit may \mathrm{V} \sqrt{\frac{\mathrm{C}}{\mathrm{L}}}.
62
MediumJee Advance2006
The capacitor of capacitance C can be charged (with the help of a resistance R ) by a voltage source V , by closing switch \mathrm{S}_1 while keeping switch \mathrm{S}_2 open. The capacitor can be connected in series with an inductor L by closing switch \mathrm{S}_2 and opening \mathrm{S}_1.
Options:
A) the charge on the capacitor is
$ \mathrm{Q}=\mathrm{Q}_0 \cos \left(\frac{\pi}{2}+\frac{t}{\sqrt{\mathrm{LC}}}\right)
B) the charge on the capacitor is
$ \mathrm{Q}=\mathrm{Q}_0 \cos \left(\frac{\pi}{2}-\frac{1}{\sqrt{\mathrm{LC}}}\right) .
C) the charge on the capacitor is
$ \mathrm{Q}=-\mathrm{LC} \frac{d^2 \mathrm{Q}}{d t^2} .
D) the charge on the capacitor is
$ \mathrm{Q}=-\frac{1}{\sqrt{\mathrm{LC}}} \frac{d^2 \mathrm{Q}}{d t^2} .
63
MediumJee Advance2021
In a circuit, a metal filament lamp is connected in series with a capacitor of capacitance C $\muF across a 200 V, 50 Hz supply. The power consumed by the lamp is 500 W while the voltage drop across it is 100 V. Assume that there is no inductive load in the circuit. Take rms values of the voltages. The magnitude of the phase-angle (in degrees) between the current and the supply voltage is \varphi . Assume, \pi\sqrt 3 \approx $ 5.The value of C is ____________.
Options:
64
MediumJee Advance2021
In a circuit, a metal filament lamp is connected in series with a capacitor of capacitance C $\muF across a 200 V, 50 Hz supply. The power consumed by the lamp is 500 W while the voltage drop across it is 100 V. Assume that there is no inductive load in the circuit. Take rms values of the voltages. The magnitude of the phase-angle (in degrees) between the current and the supply voltage is \varphi . Assume, \pi\sqrt 3 \approx 5.The value of \varphi$ is ____________.
Options:
65
EasyJee Advance2011
A series RC combination is connected to an AC voltage of angular frequency $\omega = 500 rad/s. If the impedance of the RC circuit is R\sqrt{1.25}$, the time constant (in millisecond) of the circuit is __________.
Options:
66
HardJee Advance2017
The instantaneous voltages at three terminals marked $X,Y and Z are given by {V_x} = {V_0}\,\sin \,\omega t, {V_Y} = {V_0}\,\sin \left( {\omega t + {{2\pi } \over 3}} \right) and Vz = {V_0}\sin \left( {\omega t + {{4\pi } \over 3}} \right) An ideal voltmeter is configured to read rms value of the potential difference between its terminals. It is connected between points X and Y and then between Y and Z.$ The reading(s) of the voltmeter will be
Options:
A) V_{xy}^{rms} = {V_0}\sqrt {{3 \over 2}}
B) V_{YZ}^{rms} = {V_0}\sqrt {{1 \over 2}}
C) V_{XY}^{rms} = {V_0}
D) Independent of the choice of the two terminals
67
HardJee Advance2017
In the circuit shown, $L = 1\,\mu H,C = 1\,\mu F\, and R = 1\,k\Omega . They are connected in series with an a.c. source V = {V_0}\sin \omega t$ as shown. Which of the following options is/are correct?
Options:
A) The current will be in phase with the voltage if $\omega = {10^4} rad.{s^{ - 1}}
B) The frequency at which the current will be in phase with the voltage is independent of $R
C) At $\omega \sim 0$ the current flowing through the circuit becomes nearly zero
D) At $\omega > > {10^6}rad.{s^{ - 1}},$ the circuit behaves like a capacitor
68
HardJee Advance2014
At time t = 0, terminal A in the circuit shown in the figure is connected to B by a key and an alternating current I(t) = I0 cos ($\omegat), with I0 = 1 A and \omega = 500 rad s-1 starts flowing in it with the initial direction shown in the figure. At t = {{7\pi } \over {6\omega }}, the key is switched from B to D. Now onwards only A and D are connected. A total charge Q flows from the battery to charge the capacitor fully. If C = 20 \muF, R = 10 \Omega$ and the battery is ideal with emf of 50 V, identify the correct statement(s).
Options:
A) Magnitude of the maximum charge on the capacitor before $t = {{7\pi } \over {6\omega }} is 1 \times 10-$3 C
B) The current in the left part of the circuit just before $t = {{7\pi } \over {6\omega }}$ is clockwise
C) Immediately after A is connected to D, the current in R is 10 A
D) Q = 2 $\times 10-$3 C
69
MediumJee Advance2012
In the given circuit, the AC source has $\omega$ = 100 rad/s. Considering the inductor and capacitor to be ideal, the correct choice(s) is(are)
Options:
A) The current through the circuit, I is 0.3 A.
B) The current through the circuit, I is 0.3$\sqrt2$ A.
C) The voltage across 100 $\Omega resistor = 10\sqrt2$ V.
D) The voltage across 50 $\Omega$ resistor = 10 V.
70
MediumJee Advance2011
A series RC-current is connected to AC voltage source. Consider two cases : (A) When C is without a dielectric medium and (B) when C is filled with dielectric of constant 4. The current IR through the resistor and voltage VC across the capacitor are compared in the two cases. Which of the following is/are true?
Options:
A) I_R^A > I_R^B
B) I_R^A < I_R^B
C) V_C^A > V_C^B
D) V_C^A < V_C^B
71
MediumJEE Mains2026
An inductor stores 16 J of magnetic field energy and dissipates 32 W of thermal energy due to its resistance when an a.c. current of 2 A (rms) and frequency 50 Hz flows through it. The ratio of inductive reactance to its resistance is ______. (\pi = 3.14)
Options:
72
MediumJEE Mains2026
Using a variable frequency a.c. voltage source the maximum current measured in the given LCR circuit is 50 mA for V=5 \sin (100 t) The values of L and R are shown in the figure. The capacitance of the capacitor ( C ) used is \_\_\_\_ \mu \mathrm{F}.
Options:
73
EasyJEE Mains2025
An inductor of reactance 100 \Omega, a capacitor of reactance 50 \Omega, and a resistor of resistance 50 \Omega are connected in series with an AC source of 10 \mathrm{~V}, 50 \mathrm{~Hz}. Average power dissipated by the circuit is ___________ W.
Options:
74
MediumJEE Mains2025
For ac circuit shown in figure, \mathrm{R}=100 \mathrm{k} \Omega and \mathrm{C}=100 \mathrm{pF} and the phase difference between \mathrm{V}_{\text {in }} and \left(\mathrm{V}_{\mathrm{B}}-\mathrm{V}_{\mathrm{A}}\right) is 90^{\circ}. The input signal frequency is 10^x \mathrm{rad} / \mathrm{sec}, where ' x ' is __________ .
Options:
75
EasyJEE Mains2025
An inductor of self inductance 1 H is connected in series with a resistor of 100 \pi ohm and an ac supply of 100 \pi volt, 50 Hz . Maximum current flowing in the circuit is _________ A.
Options:
76
EasyJEE Mains2025
In a series LCR circuit, a resistor of 300 \Omega, a capacitor of 25 nF and an inductor of 100 mH are used. For maximum current in the circuit, the angular frequency of the ac source is _________ \times 10^4 radians \mathrm{s}^{-1}
Options:
77
EasyJEE Mains2024
A capacitor of reactance $4 \sqrt{3} \Omega and a resistor of resistance 4 \Omega are connected in series with an ac source of peak value 8 \sqrt{2} \mathrm{~V}$. The power dissipation in the circuit is __________ W.
Options:
78
MediumJEE Mains2024
When a coil is connected across a $20 \mathrm{~V} dc supply, it draws a current of 5 \mathrm{~A}. When it is connected across 20 \mathrm{~V}, 50 \mathrm{~Hz} ac supply, it draws a current of 4 \mathrm{~A}. The self inductance of the coil is __________ \mathrm{mH}. (Take \pi=3$)
Options:
79
EasyJEE Mains2024
An alternating emf $\mathrm{E}=110 \sqrt{2} \sin 100 \mathrm{t} volt is applied to a capacitor of 2 \mu \mathrm{F}, the rms value of current in the circuit is ________ \mathrm{mA}$.
Options:
80
EasyJEE Mains2024
For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is $2.5 \mathrm{~nF}. If resistance of 200 \Omega and 100 \mathrm{~mH} inductor is being used in the given circuit. The frequency of ac source is _________ \times 10^3 \mathrm{~Hz} (given \mathrm{a}^2=10$)
Options:
81
MediumJEE Mains2024
When a $d c voltage of 100 \mathrm{~V} is applied to an inductor, a d c current of 5 \mathrm{~A} flows through it. When an ac voltage of 200 \mathrm{~V} peak value is connected to inductor, its inductive reactance is found to be 20 \sqrt{3} \Omega$. The power dissipated in the circuit is _________ W.
Options:
82
MediumJEE Mains2024
An ac source is connected in given series LCR circuit. The rms potential difference across the capacitor of $20 \mu \mathrm{F}$ is __________ V.
Options:
83
MediumJEE Mains2024
A alternating current at any instant is given by $i=[6+\sqrt{56} \sin (100 \pi t+\pi / 3)] A. The r m s$ value of the current is ______ A.
Options:
84
EasyJEE Mains2024
A power transmission line feeds input power at $2.3 \mathrm{~kV} to a step down transformer with its primary winding having 3000 turns. The output power is delivered at 230 \mathrm{~V} by the transformer. The current in the primary of the transformer is 5 \mathrm{~A} and its efficiency is 90 \%. The winding of transformer is made of copper. The output current of transformer is _________ A$.
Options:
85
EasyJEE Mains2024
A series LCR circuit with $\mathrm{L}=\frac{100}{\pi} \mathrm{mH}, \mathrm{C}=\frac{10^{-3}}{\pi} \mathrm{F} and \mathrm{R}=10 \Omega, is connected across an ac source of 220 \mathrm{~V}, 50 \mathrm{~Hz}$ supply. The power factor of the circuit would be ________.
Options:
86
MediumJEE Mains2023
In the given figure, an inductor and a resistor are connected in series with a battery of emf E volt. $\frac{E^{a}}{2 b} \mathrm{~J} / s represents the maximum rate at which the energy is stored in the magnetic field (inductor). The numerical value of \frac{b}{a}$ will be __________.
Options:
87
EasyJEE Mains2023
A coil has an inductance of $2 \mathrm{H} and resistance of 4 ~\Omega. A 10 \mathrm{~V} is applied across the coil. The energy stored in the magnetic field after the current has built up to its equilibrium value will be ___________ \times 10^{-2} \mathrm{~J}$.
Options:
88
MediumJEE Mains2023
A series combination of resistor of resistance $100 ~\Omega, inductor of inductance 1 ~\mathrm{H} and capacitor of capacitance 6.25 ~\mu \mathrm{F}$ is connected to an ac source. The quality factor of the circuit will be __________
Options:
89
EasyJEE Mains2023
An oscillating LC circuit consists of a $75 ~\mathrm{mH} inductor and a 1.2 ~\mu \mathrm{F} capacitor. If the maximum charge to the capacitor is 2.7 ~\mu \mathrm{C}. The maximum current in the circuit will be ___________ \mathrm{mA}
Options:
90
EasyJEE Mains2023
An ideal transformer with purely resistive load operates at $12 ~\mathrm{kV} on the primary side. It supplies electrical energy to a number of nearby houses at 120 \mathrm{~V}. The average rate of energy consumption in the houses served by the transformer is 60 \mathrm{kW}. The value of resistive load (\mathrm{Rs}) required in the secondary circuit will be ___________ \mathrm{m} \Omega$.
Options:
91
EasyJEE Mains2023
A square shaped coil of area $70 \mathrm{~cm}^{2} having 600 turns rotates in a magnetic field of 0.4 ~\mathrm{wbm}^{-2}, about an axis which is parallel to one of the side of the coil and perpendicular to the direction of field. If the coil completes 500 revolution in a minute, the instantaneous emf when the plane of the coil is inclined at 60^{\circ} with the field, will be ____________ V. (Take \pi=\frac{22}{7}$)
Options:
92
EasyJEE Mains2023
A series LCR circuit is connected to an ac source of $220 \mathrm{~V}, 50 \mathrm{~Hz}. The circuit contain a resistance \mathrm{R}=100 ~\Omega and an inductor of inductive reactance \mathrm{X}_{\mathrm{L}}=79.6 ~\Omega. The capacitance of the capacitor needed to maximize the average rate at which energy is supplied will be _________ \mu \mathrm{F}$.
Options:
93
EasyJEE Mains2023
A series \mathrm{LCR} circuit consists of \mathrm{R}=80 \Omega, \mathrm{X}_{\mathrm{L}}=100 \Omega, and \mathrm{X}_{\mathrm{C}}=40 \Omega. The input voltage is 2500 \cos (100 \pi \mathrm{t}) \mathrm{V}. The amplitude of current, in the circuit, is _________ A.
Options:
94
EasyJEE Mains2023
An inductor of $0.5 ~\mathrm{mH}, a capacitor of 20 ~\mu \mathrm{F} and resistance of 20 ~\Omega are connected in series with a 220 \mathrm{~V} ac source. If the current is in phase with the emf, the amplitude of current of the circuit is \sqrt{x} A. The value of x$ is ___________
Options:
95
EasyJEE Mains2023
In an ac generator, a rectangular coil of 100 turns each having area 14 \times 10^{-2} \mathrm{~m}^{2} is rotated at 360 ~\mathrm{rev} / \mathrm{min} about an axis perpendicular to a uniform magnetic field of magnitude 3.0 \mathrm{~T}. The maximum value of the emf produced will be ________ V. \left(\right. Take \left.\pi=\frac{22}{7}\right)
Options:
96
EasyJEE Mains2023
An inductor of inductance 2 $\mathrm{\mu H} is connected in series with a resistance, a variable capacitor and an AC source of frequency 7 kHz. The value of capacitance for which maximum current is drawn into the circuit \frac{1}{x}\mathrm{F}, where the value of x is ___________. (Take \pi=\frac{22}{7}$)
Options:
97
EasyJEE Mains2023
A series LCR circuit is connected to an AC source of 220 V, 50 Hz. The circuit contains a resistance R = 80$\Omega, an inductor of inductive reactance \mathrm{X_L=70\Omega}, and a capacitor of capacitive reactance \mathrm{X_C=130\Omega}. The power factor of circuit is \frac{x}{10}. The value of x$ is :
Options:
98
EasyJEE Mains2023
An LCR series circuit of capacitance 62.5 nF and resistance of 50 $\Omega, is connected to an A.C. source of frequency 2.0 kHz. For maximum value of amplitude of current in circuit, the value of inductance is __________ mH. (Take \pi^2=10$)
Options:
99
MediumJEE Mains2023
In the circuit shown in the figure, the ratio of the quality factor and the band width is ___________ s.
Options:
100
MediumJEE Mains2022
A capacitor of capacitance 500 $\mu$F is charged completely using a dc supply of 100 V. It is now connected to an inductor of inductance 50 mH to form an LC circuit. The maximum current in LC circuit will be _______ A.
Options:
101
MediumJEE Mains2022
The frequencies at which the current amplitude in an LCR series circuit becomes $\frac{1}{\sqrt{2}} times its maximum value, are 212\,\mathrm{rad} \,\mathrm{s}^{-1} and 232 \,\mathrm{rad} \,\mathrm{s}^{-1}. The value of resistance in the circuit is R=5 \,\Omega. The self inductance in the circuit is __________ \mathrm{mH}$.
Options:
102
MediumJEE Mains2022
To light, a $50 \mathrm{~W}, 100 \mathrm{~V} lamp is connected, in series with a capacitor of capacitance \frac{50}{\pi \sqrt{x}} \mu F, with 200 \mathrm{~V}, 50 \mathrm{~Hz} \,\mathrm{AC} source. The value of x$ will be ___________.
Options:
103
MediumJEE Mains2022
The effective current I in the given circuit at very high frequencies will be ___________ A.
Options:
104
EasyJEE Mains2022
A series LCR circuit with $R = {{250} \over {11}}\,\Omega and {X_L} = {{70} \over {11}}\,\Omega is connected across a 220 V, 50 Hz supply. The value of capacitance needed to maximize the average power of the circuit will be _________ \muF. (Take : \pi = {{22} \over 7}$)
Options:
105
EasyJEE Mains2022
An inductor of 0.5 mH, a capacitor of 200 $\muF and a resistor of 2 \Omega are connected in series with a 220 V ac source. If the current is in phase with the emf, the frequency of ac source will be ____________ \times$ 102 Hz.
Options:
106
MediumJEE Mains2022
In the given circuit, the magnitude of VL and VC are twice that of VR. Given that f = 50 Hz, the inductance of the coil is ${1 \over {K\pi }}$ mH. The value of K is ____________.
Options:
107
MediumJEE Mains2022
An AC source is connected to an inductance of 100 mH, a capacitance of 100 $\muF and a resistance of 120 \Omega as shown in figure. The time in which the resistance having a thermal capacity 2 J/^\circC will get heated by 16^\circ$C is _____________ s.
Options:
108
MediumJEE Mains2022
A telegraph line of length 100 km has a capacity of 0.01 $\muF/km and it carries an alternating current at 0.5 kilo cycle per second. If minimum impedance is required, then the value of the inductance that needs to be introduced in series is _____________ mH. (if \pi = \sqrt{10}$)
Options:
109
EasyJEE Mains2022
A 220 V, 50 Hz AC source is connected to a 25 V, 5 W lamp and an additional resistance R in series (as shown in figure) to run the lamp at its peak brightness, then the value of R (in ohm) will be _____________.
Options:
110
MediumJEE Mains2022
A 110 V, 50 Hz, AC source is connected in the circuit (as shown in figure). The current through the resistance 55 $\Omega$, at resonance in the circuit, will be __________ A.
Options:
111
EasyJEE Mains2022
In a series LCR circuit, the inductance, capacitance and resistance are L = 100 mH, C = 100 $\muF and R = 10 \Omega$ respectively. They are connected to an AC source of voltage 220 V and frequency of 50 Hz. The approximate value of current in the circuit will be ___________ A.
Options:
112
EasyJEE Mains2022
As shown in the figure an inductor of inductance 200 mH is connected to an AC source of emf 220 V and frequency 50 Hz. The instantaneous voltage of the source is 0 V when the peak value of current is ${{\sqrt a } \over \pi } A. The value of a$ is ___________.
Options:
113
MediumJEE Mains2021
At very high frequencies, the effective impendence of the given circuit will be ________________ $\Omega$.
Options:
114
MediumJEE Mains2021
An ac circuit has an inductor and a resistor resistance R in series, such that XL = 3R. Now, a capacitor is added in series such that XC = 2R. The ratio of new power factor with the old power factor of the circuit is $\sqrt 5 :x$. The value of x is ___________.
Options:
115
MediumJEE Mains2021
The alternating current is given by $i = \left\{ {\sqrt {42} \sin \left( {{{2\pi } \over T}t} \right) + 10} \right\}A$The r.m.s. value of of this current is ................. A.
Options:
116
MediumJEE Mains2021
Consider an electrical circuit containing a two way switch 'S'. Initially S is open and then T1 is connected to T2. As the current in R = 6$\Omega attains a maximum value of steady state level, T1 is disconnected from T2 and immediately connected to T3. Potential drop across r = 3\Omega$ resistor immediately after T1 is connected to T3 is __________ V. (Round off to the Nearest Integer)
Options:
117
MediumJEE Mains2021
Two circuits are shown in the figure (a) & (b). At a frequency of ____________ rad/s the average power dissipated in one cycle will be same in both the circuits.
Options:
118
MediumJEE Mains2021
An inductor of 10 mH is connected to a 20V battery through a resistor of 10 k$\Omega and a switch. After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after 1 \mus is {x \over {100}} mA. Then x is equal to ___________. (Take e-$1 = 0.37)
Options:
119
EasyJEE Mains2021
A series LCR circuit of R = 5$\Omega, L = 20 mH and C = 0.5 \muF is connected across an AC supply of 250 V, having variable frequency. The power dissipated at resonance condition is ______________ \times$ 102 W.
Options:
120
MediumJEE Mains2021
In an LCR series circuit, an inductor 30 mH and a resistor 1 $\Omega are connected to an AC source of angular frequency 300 rad/s. The value of capacitance for which, the current leads the voltage by 45^\circ is {1 \over x} \times {10^{ - 3}}$ F. Then the value of x is ____________.
Options:
121
EasyJEE Mains2021
A sinusoidal voltage of peak value 250 V is applied to a series LCR circuit, in which R = 8$\Omega, L = 24 mH and C = 60 \mu$F. The value of power dissipated at resonant condition is 'x' kW. The value of x to the nearest integer is ____________.
Options:
122
MediumJEE Mains2021
In a series LCR resonant circuit, the quality factor is measured as 100. If the inductance is increased by two fold and resistance is decreased by two fold, then the quality factor after this change will be __________.
Options:
123
MediumJEE Mains2021
A transmitting station releases waves of wavelength 960 m. A capacitor of 2.56 $\muF is used in the resonant circuit. The self inductance of coil necessary for resonance is __________ \times 10-$8 H.
Options:
124
EasyJEE Mains2021
A series L-C-R circuit is designed to resonate at an angular frequency $\omega0 = 105 rad/s. The circuit draws 16W power from 120V source at resonance. The value of resistance 'R' in the circuit is _________ \Omega$.
Options:
125
EasyJEE Mains2021
A common transistor radio set requires 12 V (D.C.) for its operation. The D.C. source is constructed by using a transformer and a rectifier circuit, which are operated at 220 V (A.C.) on standard domestic A.C. supply. The number of turns of secondary coil are 24, then the number of turns of primary are ___________.
Options:
126
EasyJEE Mains2021
A resonance circuit having inductance and resistance 2 $\times 10-4 H and 6.28\Omega respectively oscillates at 10 MHz frequency. The value of quality factor of this resonator is ___________. [\pi$ = 3.14]
Options:
127
MediumJEE Mains2020
In a series LR circuit, power of 400W is dissipated from a source of 250 V, 50 Hz. The power factor of the circuit is 0.8. In order to bring the power factor to unity, a capacitor of value C is added in series to the L and R. Taking the value of C as $\left( {{n \over {3\pi }}} \right) \mu $F, then value of n is __________.
Options:
128
EasyJEE Mains2026
The electric current in the circuit is given as i=i_{\mathrm{o}}(t / T). The r.m.s current for the period t=0 to t=T is \_\_\_\_ .
Options:
A) \frac{i_{\mathrm{o}}}{\sqrt{2}}
B) \frac{i_o}{\sqrt{3}}
C) i_{\mathrm{o}}
D) \frac{i_o}{\sqrt{6}}
129
MediumJEE Mains2026
For the series LCR circuit connected with 220 \mathrm{~V}, 50 \mathrm{~Hz} a.c source as shown in the figure, the power factor is \frac{\alpha}{10}. The value of \alpha is \_\_\_\_ .
Options:
A) 4
B) 8
C) 6
D) 10
130
MediumJEE Mains2026
A capacitor C is first charged fully with potential difference of V_0 and disconnected from the battery. The charged capacitor is connected across an inductor having inductance L. In t s, 25% of the initial energy in the capacitor is transferred to the inductor. The value of t is ________ s.
Options:
A) \frac{\pi \sqrt{LC}}{3}
B) \frac{\pi \sqrt{LC}}{2}
C) \pi \sqrt{\frac{LC}{2}}
D) \frac{\pi \sqrt{LC}}{6}
131
MediumJEE Mains2025
An ac current is represented as $i=5 \sqrt{2}+10 \cos \left(650 \pi t+\frac{\pi}{6}\right) A m p$ The r.m.s value of the current is
Options:
A) 10 Amp
B) 5 \sqrt{2} \mathrm{~Amp}
C) 100 Amp
D) 50 Amp
132
EasyJEE Mains2025
An alternating current is represented by the equation, i=100 \sqrt{2} \sin (100 \pi t) ampere. The RMS value of current and the frequency of the given alternating current are
Options:
A) \frac{100}{\sqrt{2}} \mathrm{~A}, 100 \mathrm{~Hz}
B) 50 \sqrt{2} \mathrm{~A}, 50 \mathrm{~Hz}
C) 100 \sqrt{2} \mathrm{~A}, 100 \mathrm{~Hz}
D) 100 \mathrm{~A}, 50 \mathrm{~Hz}
133
EasyJEE Mains2025
An electric bulb rated as 100 \mathrm{~W}-220 \mathrm{~V} is connected to an ac source of rms voltage 220 V. The peak value of current through the bulb is :
Options:
A) 0.32 A
B) 0.64 A
C) 0.45 A
D) 2.2 A
134
MediumJEE Mains2025
An alternating current is given by \mathrm{I}=\mathrm{I}_{\mathrm{A}} \sin \omega \mathrm{t}+\mathrm{I}_{\mathrm{B}} \cos \omega \mathrm{t}. The r.m.s current will be
Options:
A) \frac{\sqrt{\mathrm{I}_{\mathrm{A}}^2+\mathrm{I}_{\mathrm{B}}^2}}{2}
B) \sqrt{\frac{\mathrm{I}_{\mathrm{A}}^2+\mathrm{I}_{\mathrm{B}}^2}{2}}
C) \frac{\left|\mathrm{I}_{\mathrm{A}}+\mathrm{I}_{\mathrm{B}}\right|}{\sqrt{2}}
D) \sqrt{\mathrm{I}_{\mathrm{A}}^2+\mathrm{I}_{\mathrm{B}}^2}
135
EasyJEE Mains2025
A series LCR circuit is connected to an alternating source of emf E. The current amplitude at resonant frequency is I_0. If the value of resistance R becomes twice of its initial value then amplitude of current at resonance will be
Options:
A) \frac{\mathrm{I}_0}{2}
B) \frac{\mathrm{I}_0}{\sqrt{2}}
C) 2 \mathrm{I}_0
D) \mathrm{I_0}
136
EasyJEE Mains2024
A bulb and a capacitor are connected in series across an ac supply. A dielectric is then placed between the plates of the capacitor. The glow of the bulb :
Options:
A) becomes zero
B) remains same
C) increases
D) decreases
137
MediumJEE Mains2024
A coil of negligible resistance is connected in series with $90 \Omega resistor across 120 \mathrm{~V}, 60 \mathrm{~Hz} supply. A voltmeter reads 36 \mathrm{~V}$ across resistance. Inductance of the coil is :
Options:
A) 0.91 H
B) 0.76 H
C) 2.86 H
D) 0.286 H
138
EasyJEE Mains2024
A LCR circuit is at resonance for a capacitor C, inductance L and resistance R. Now the value of resistance is halved keeping all other parameters same. The current amplitude at resonance will be now:
Options:
A) halved
B) same
C) Zero
D) double
139
MediumJEE Mains2024
Given below are two statements : Statement I : In an LCR series circuit, current is maximum at resonance. Statement II : Current in a purely resistive circuit can never be less than that in a series LCR circuit when connected to same voltage source. In the light of the above statements, choose the correct from the options given below :
Options:
A) Statement I is true but Statement II is false
B) Statement I is false but Statement II is true
C) Both Statement I and Statement II are true
D) Both Statement I and Statement II are false
140
EasyJEE Mains2024
A series LCR circuit is subjected to an ac signal of $200 \mathrm{~V}, 50 \mathrm{~Hz}. If the voltage across the inductor (\mathrm{L}=10 \mathrm{~mH}) is 31.4 \mathrm{~V}$, then the current in this circuit is _______.
Options:
A) 10 A
B) 10 mA
C) 68 A
D) 63 A
141
EasyJEE Mains2024
An alternating voltage of amplitude $40 \mathrm{~V} and frequency 4 \mathrm{~kHz} is applied directly across the capacitor of 12 \mu \mathrm{F}$. The maximum displacement current between the plates of the capacitor is nearly :
Options:
A) 10 A
B) 8 A
C) 13 A
D) 12 A
142
EasyJEE Mains2024
Match List I with List II LIST I LIST II A. Purely capacitive circuit I. B. Purely inductive circuit II. C. LCR series at resonance III. D. LCR series circuit IV. Choose the correct answer from the options given below:
Options:
A) A-IV. B-I, C-III, D-II
B) A-I. B-IV, C-II, D-III
C) A-IV. B-I, C-II, D-III
D) A-I. B-IV, C-III, D-II
143
MediumJEE Mains2024
In an ac circuit, the instantaneous current is zero, when the instantaneous voltage is maximum. In this case, the source may be connected to : A. pure inductor. B. pure capacitor. C. pure resistor. D. combination of an inductor and capacitor. Choose the correct answer from the options given below :
Options:
A) A, B and C only
B) A and B only
C) A, B and D only
D) B, C and D only
144
EasyJEE Mains2024
A parallel plate capacitor has a capacitance \mathrm{C}=200~ \mathrm{pF}. It is connected to 230 \mathrm{~V} ac supply with an angular frequency 300~ \mathrm{rad} / \mathrm{s}. The rms value of conduction current in the circuit and displacement current in the capacitor respectively are :
Options:
A) 14.3 ~\mu \mathrm{A} and 143 ~\mu \mathrm{A}
B) 13.8 ~\mu \mathrm{A} and 13.8 ~\mu \mathrm{A}
C) 13.8 ~\mu \mathrm{A} and 138 ~\mu \mathrm{A}
D) 1.38 ~\mu \mathrm{A} and 1.38 ~\mu \mathrm{A}
145
EasyJEE Mains2024
In series LCR circuit, the capacitance is changed from C to 4 C. To keep the resonance frequency unchanged, the new inductance should be:
Options:
A) increased by 2 \mathrm{~L}
B) reduced by \frac{1}{4} \mathrm{~L}
C) reduced by \frac{3}{4} \mathrm{~L}
D) increased to 4 \mathrm{~L}
146
EasyJEE Mains2024
An AC voltage $V=20 \sin 200 \pi t is applied to a series LCR circuit which drives a current I=10 \sin \left(200 \pi t+\frac{\pi}{3}\right)$. The average power dissipated is:
Options:
A) 21.6 W
B) 200 W
C) 173.2 W
D) 50 W
147
EasyJEE Mains2024
An alternating voltage $V(t)=220 \sin 100 \pi t volt is applied to a purely resistive load of 50 \Omega$. The time taken for the current to rise from half of the peak value to the peak value is:
Options:
A) 7.2 ms
B) 3.3 ms
C) 5 ms
D) 2.2 ms
148
EasyJEE Mains2024
Primary coil of a transformer is connected to $220 \mathrm{~V} ac. Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistances shown in figure. The output voltage \left(V_0\right)$ is :
Options:
A) 7 V
B) 44 V
C) 22 V
D) 15 V
149
MediumJEE Mains2024
A series L.R circuit connected with an ac source $E=(25 \sin 1000 t) V has a power factor of \frac{1}{\sqrt{2}}. If the source of emf is changed to \mathrm{E}=(20 \sin 2000 \mathrm{t}) \mathrm{V}$, the new power factor of the circuit will be :
Options:
A) \frac{1}{\sqrt{3}}
B) \frac{1}{\sqrt{2}}
C) \frac{1}{\sqrt{5}}
D) \frac{1}{\sqrt{7}}
150
EasyJEE Mains2024
In an a.c. circuit, voltage and current are given by: $V=100 \sin (100 t) V and I=100 \sin \left(100 t+\frac{\pi}{3}\right) \mathrm{mA}$ respectively. The average power dissipated in one cycle is:
Options:
A) 5 W
B) 25 W
C) 2.5 W
D) 10 W
151
EasyJEE Mains2024
A capacitor of capacitance $100 \mu \mathrm{F} is charged to a potential of 12 \mathrm{~V} and connected to a 6.4 \mathrm{~mH}$ inductor to produce oscillations. The maximum current in the circuit would be :
Options:
A) 2.0 A
B) 3.2 A
C) 1.5 A
D) 1.2 A
152
EasyJEE Mains2024
Primary side of a transformer is connected to $230 \mathrm{~V}, 50 \mathrm{~Hz} supply. Turns ratio of primary to secondary winding is 10: 1. Load resistance connected to secondary side is 46 \Omega$. The power consumed in it is :
Options:
A) 11.5 W
B) 12.5 W
C) 10.0 W
D) 12.0 W
153
EasyJEE Mains2023
Given below are two statements: Statement I : An AC circuit undergoes electrical resonance if it contains either a capacitor or an inductor. Statement II : An AC circuit containing a pure capacitor or a pure inductor consumes high power due to its non-zero power factor. In the light of above statements, choose the correct answer form the options given below:
Options:
A) Both Statement I and Statement II are false
B) Statement I is true but statement II is false
C) Statement I is false but statement II is true
D) Both Statement I and Statement II are true
154
EasyJEE Mains2023
Given below are two statements: Statement I : When the frequency of an a.c source in a series LCR circuit increases, the current in the circuit first increases, attains a maximum value and then decreases. Statement II : In a series LCR circuit, the value of power factor at resonance is one. In the light of given statements, choose the most appropriate answer from the options given below.
Options:
A) Both Statement I and Statement II are False.
B) Statement I is incorrect but Statement II is true.
C) Both Statement I and Statement II are true.
D) Statement I is correct but Statement II is false.
155
EasyJEE Mains2023
As per the given graph, choose the correct representation for curve $\mathrm{A} and curve B. Where \mathrm{X}_{\mathrm{C}}= reactance of pure capacitive circuit connected with A.C. source \mathrm{X}_{\mathrm{L}}= reactance of pure inductive circuit connected with \mathrm{A} . \mathrm{C}. source R = impedance of pure resistive circuit connected with A.C. source. \mathrm{Z}= Impedance of the LCR series circuit \}
Options:
A) \mathrm{A}=\mathrm{X}_{\mathrm{L}}, \mathrm{B}=\mathrm{R}
B) \mathrm{A}=\mathrm{X}_{L}, \mathrm{~B}=Z
C) \mathrm{A}=\mathrm{X}_{\mathrm{C}}, \mathrm{B}=\mathrm{X}_{\mathrm{L}}
D) \mathrm{A}=\mathrm{X}_{\mathrm{C}}, \mathrm{B}=\mathrm{R}
156
EasyJEE Mains2023
Given below are two statements: Statement I : Maximum power is dissipated in a circuit containing an inductor, a capacitor and a resistor connected in series with an AC source, when resonance occurs Statement II : Maximum power is dissipated in a circuit containing pure resistor due to zero phase difference between current and voltage. In the light of the above statements, choose the correct answer from the options given below:
Options:
A) Statement I is false but Statement II is true
B) Both Statement I and Statement II are false
C) Statement I is true but Statement II is false
D) Both Statement I and Statement II are true
157
EasyJEE Mains2023
A capacitor of capacitance $150.0 ~\mu \mathrm{F} is connected to an alternating source of emf given by \mathrm{E}=36 \sin (120 \pi \mathrm{t}) \mathrm{V}$. The maximum value of current in the circuit is approximately equal to :
Options:
A) \frac{1}{\sqrt{2}} A
B) 2 \sqrt{2} A
C) \sqrt{2} A
D) 2 A
158
EasyJEE Mains2023
Match List - I with List - II : List I List II A. AC generator I. Presence of both L and C B. Transformer II. Electromagnetic Induction C. Resonance phenomenon to occur III. Quality factor D. Sharpness of resonance IV. Mutual Induction Choose the correct answer from the options given below :
Options:
A) A-II, B-I, C-III, D-IV
B) A-IV, B-III, C-I, D-II
C) A-II, B-IV, C-I, D-III
D) A-IV, B-II, C-I, D-III
159
EasyJEE Mains2023
An alternating voltage source \mathrm{V}=260 \sin (628 \mathrm{t} ) is connected across a pure inductor of 5 \mathrm{mH} Inductive reactance in the circuit is :
Options:
A) 6.28 \Omega
B) 0.318 \Omega
C) 0.5 \Omega
D) 3.14 \Omega
160
EasyJEE Mains2023
If $\mathrm{R}, \mathrm{X}_{\mathrm{L}}, and \mathrm{X}_{\mathrm{C}}$ represent resistance, inductive reactance and capacitive reactance. Then which of the following is dimensionless :
Options:
A) \frac{R}{X_{L} X_{C}}
B) R X_{L} X_{C}
C) \frac{R}{\sqrt{X_{L} X_{C}}}
D) R \frac{X_{L}}{X_{C}}
161
MediumJEE Mains2023
In the given circuit, rms value of current \left(I_{\mathrm{rms}}\right) through the resistor R is:
Options:
A) 2 \sqrt{2} \mathrm{~A}
B) 2 \mathrm{~A}
C) \frac{1}{2} \mathrm{~A}
D) 20 \mathrm{~A}
162
MediumJEE Mains2023
In a series LR circuit with $\mathrm{X_L=R}, power factor P1. If a capacitor of capacitance C with \mathrm{X_C=X_L}$ is added to the circuit the power factor becomes P2. The ratio of P1 to P2 will be :
Options:
A) 1 : $\sqrt2
B) 1 : 3
C) 1 : 2
D) 1 : 1
163
MediumJEE Mains2023
For the given figures, choose the correct options :
Options:
A) The rms current in circuit (b) can be larger than that in (a)
B) The rms current in figure (a) is always equal to that in figure (b)
C) The rms current in circuit (b) can never be larger than that in (a)
D) At resonance, current in (b) is less than that in (a)
164
EasyJEE Mains2023
In an LC oscillator, if values of inductance and capacitance become twice and eight times, respectively, then the resonant frequency of oscillator becomes $x times its initial resonant frequency \omega_0. The value of x$ is :
Options:
A) 1/4
B) 1/16
C) 4
D) 16
165
MediumJEE Mains2022
A circuit element $\mathrm{X} when connected to an a.c. supply of peak voltage 100 \mathrm{~V} gives a peak current of 5 \mathrm{~A} which is in phase with the voltage. A second element \mathrm{Y} when connected to the same a.c. supply also gives the same value of peak current which lags behind the voltage by \frac{\pi}{2}. If \mathrm{X} and \mathrm{Y}$ are connected in series to the same supply, what will be the rms value of the current in ampere?
Options:
A) \frac{10}{\sqrt{2}}
B) \frac{5}{\sqrt{2}}
C) 5 \sqrt{2}
D) \frac{5}{2}
166
EasyJEE Mains2022
An alternating emf $\mathrm{E}=440 \sin 100 \pi \mathrm{t} is applied to a circuit containing an inductance of \frac{\sqrt{2}}{\pi} \mathrm{H}$. If an a.c. ammeter is connected in the circuit, its reading will be :
Options:
A) 4.4 A
B) 1.55 A
C) 2.2 A
D) 3.11 A
167
MediumJEE Mains2022
A coil of inductance 1 H and resistance $100 \,\Omega is connected to a battery of 6 V. Determine approximately : (a) The time elapsed before the current acquires half of its steady - state value. (b) The energy stored in the magnetic field associated with the coil at an instant 15 ms after the circuit is switched on. (Given \ln 2=0.693, \mathrm{e}^{-3 / 2}=0.25$)
Options:
A) t = 10 ms; U = 2 mJ
B) t = 10 ms; U = 1 mJ
C) t = 7 ms; U = 1 mJ
D) t = 7 ms; U = 2 mJ
168
EasyJEE Mains2022
A transformer operating at primary voltage $8 \,\mathrm{kV} and secondary voltage 160 \mathrm{~V} serves a load of 80 \mathrm{~kW}$. Assuming the transformer to be ideal with purely resistive load and working on unity power factor, the loads in the primary and secondary circuit would be
Options:
A) 800 \,\Omega and 1.06 \,\Omega
B) 10 \,\Omega and 500 \,\Omega
C) 800 \,\Omega and 0.32 \,\Omega
D) 1.06 \,\Omega and 500 \,\Omega
169
EasyJEE Mains2022
The equation of current in a purely inductive circuit is $5 \sin \left(49\, \pi t-30^{\circ}\right). If the inductance is 30 \,\mathrm{mH} then the equation for the voltage across the inductor, will be : \left\{\right. Let \left.\pi=\frac{22}{7}\right\}
Options:
A) 1.47 \sin \left(49 \pi t-30^{\circ}\right)
B) 1.47 \sin \left(49 \pi t+60^{\circ}\right)
C) 23.1 \sin \left(49 \pi t-30^{\circ}\right)
D) 23.1 \sin \left(49 \pi t+60^{\circ}\right)
170
MediumJEE Mains2022
A series LCR circuit has $\mathrm{L}=0.01\, \mathrm{H}, \mathrm{R}=10\, \Omega and \mathrm{C}=1 \mu \mathrm{F} and it is connected to ac voltage of amplitude \left(\mathrm{V}_{\mathrm{m}}\right) 50 \mathrm{~V}. At frequency 60 \%$ lower than resonant frequency, the amplitude of current will be approximately :
Options:
A) 466 mA
B) 312 mA
C) 238 mA
D) 196 mA
171
EasyJEE Mains2022
A direct current of $4 \mathrm{~A} and an alternating current of peak value 4 \mathrm{~A} flow through resistance of 3\, \Omega and 2\,\Omega$ respectively. The ratio of heat produced in the two resistances in same interval of time will be :
Options:
A) 3 : 2
B) 3 : 1
C) 3 : 4
D) 4 : 3
172
EasyJEE Mains2022
In a series $L R circuit X_{L}=R and power factor of the circuit is P_{1}. When capacitor with capacitance C such that X_{L}=X_{C} is put in series, the power factor becomes P_{2}. The ratio \frac{P_{1}}{P_{2}}$ is:
Options:
A) \frac{1}{2}
B) \frac{1}{\sqrt{2}}
C) \frac{\sqrt{3}}{\sqrt{2}}
D) 2 : 1
173
EasyJEE Mains2022
When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on :
Options:
A) Electromagnetic induction
B) Resonance in ac circuits
C) Mutual induction in ac circuits
D) Interference of electromagnetic waves
174
EasyJEE Mains2022
To increase the resonant frequency in series LCR circuit,
Options:
A) source frequency should be increased.
B) another resistance should be added in series with the first resistance.
C) another capacitor should be added in series with the first capacitor.
D) the source frequency should be decreased.
175
EasyJEE Mains2022
In series RLC resonator, if the self inductance and capacitance become double, the new resonant frequency (f2) and new quality factor (Q2) will be : (f1 = original resonant frequency, Q1 = original quality factor)
Options:
A) {f_2} = {{{f_1}} \over 2} and {Q_2} = {Q_1}
B) {f_2} = {f_1} and {Q_2} = {{{Q_1}} \over {{Q_2}}}
C) {f_2} = 2{f_1} and {Q_2} = {Q_1}
D) {f_2} = {f_1} and {Q_2} = 2{Q_1}
176
MediumJEE Mains2022
For a series LCR circuit, I vs $\omega curve is shown : (a) To the left of \omegar, the circuit is mainly capacitive. (b) To the left of \omegar, the circuit is mainly inductive. (c) At \omegar, impedance of the circuit is equal to the resistance of the circuit. (d) At \omega$r, impedance of the circuit is 0. Choose the most appropriate answer from the options given below :
Options:
A) (a) and (d) only.
B) (b) and (d) only.
C) (a) and (c) only.
D) (b) and (c) only.
177
EasyJEE Mains2022
If L, C and R are the self inductance, capacitance and resistance respectively, which of the following does not have the dimension of time?
Options:
A) RC
B) {L \over R}
C) \sqrt{LC}
D) {L \over C}
178
EasyJEE Mains2022
The current flowing through an ac circuit is given by I = 5 sin(120$\pi$t)A How long will the current take to reach the peak value starting from zero?
Options:
A) {1 \over {60}}$ s
B) 60 s
C) {1 \over {120}}$ s
D) {1 \over {240}}$ s
179
EasyJEE Mains2022
A sinusoidal voltage V(t) = 210 sin 3000 t volt is applied to a series LCR circuit in which L = 10 mH, C = 25 $\muF and R = 100 \Omega. The phase difference (\Phi $) between the applied voltage and resultant current will be :
Options:
A) tan$-$1(0.17)
B) tan$-$1(9.46)
C) tan$-$1(0.30)
D) tan$-$1(13.33)
180
EasyJEE Mains2022
Match List-I with List-II. List - I List -II (A) AC generator (I) Detects the presence of current in the circuit (B) Galvanometer (II) Converts mechanical energy into electrical energy (C) Transformer (III) Works on the principle of resonance in AC circuit (D) Metal detector (IV) Changes an alternating voltage for smaller or greater value Choose the correct answer from the options given below :
Options:
A) (A) - (II), (B) - (I), (C) - (IV), (D) - (III)
B) (A) - (II), (B) - (I), (C) - (III), (D) - (IV)
C) (A) - (III), (B) - (IV), (C) - (II), (D) - (I)
D) (A) - (III), (B) - (I), (C) - (II), (D) - (IV)
181
EasyJEE Mains2022
If wattless current flows in the AC circuit, then the circuit is :
Options:
A) Purely Resistive circuit
B) Purely Inductive circuit
C) LCR series circuit
D) RC series circuit only
182
EasyJEE Mains2022
Given below are two statements : Statement I : The reactance of an ac circuit is zero. It is possible that the circuit contains a capacitor and an inductor. Statement II : In ac circuit, the average power delivered by the source never becomes zero. In the light of the above statements, choose the correct answer from the options given below.
Options:
A) Both Statement I and Statement II are true.
B) Both Statement I and Statement II are false.
C) Statement I is true but Statement II is false.
D) Statement I is false but Statement II is true.
183
EasyJEE Mains2022
A resistance of 40 $\Omega$ is connected to a source of alternating current rated 220 V, 50 Hz. Find the time taken by the current to change from its maximum value to the rms value :
Options:
A) 2.5 ms
B) 1.25 ms
C) 2.5 s
D) 0.25 s
184
MediumJEE Mains2021
For the given circuit the current i through the battery when the key in closed and the steady state has been reached is __________.
Options:
A) 6 A
B) 25 A
C) 10 A
D) 0 A
185
EasyJEE Mains2021
In an ac circuit, an inductor, a capacitor and a resistor are connected in series with XL = R = XC. Impedance of this circuit is :
Options:
A) 2R2
B) Zero
C) R
D) R$\sqrt 2
186
MediumJEE Mains2021
In the given circuit the AC source has $\omega$ = 100 rad s-1. Considering the inductor and capacitor to be ideal, what will be the current I flowing through the circuit?
Options:
A) 5.9 A
B) 3.16 A
C) 0.94 A
D) 6 A
187
EasyJEE Mains2021
A series LCR circuit driven by 300 V at a frequency of 50 Hz contains a resistance R = 3 k$\Omega, an inductor of inductive reactance XL = 250 \pi\Omega and an unknown capacitor. The value of capacitance to maximize the average power should be : (Take \pi$2 = 10)
Options:
A) 4 $\mu$F
B) 25 $\mu$F
C) 400 $\mu$F
D) 40 $\mu$F
188
EasyJEE Mains2021
A 100$\Omega resistance, a 0.1 \mu$F capacitor and an inductor are connected in series across a 250 V supply at variable frequency. Calculate the value of inductance of inductor at which resonance will occur. Given that the resonant frequency is 60 Hz.
Options:
A) 0.70 H
B) 70.3 mH
C) 7.03 $\times 10-$5 H
D) 70.3 H
189
EasyJEE Mains2021
A 0.07 H inductor and a 12$\Omega resistor are connected in series to a 220V, 50 Hz ac source. The approximate current in the circuit and the phase angle between current and source voltage are respectively. [Take \pi as {{22} \over 7}$]
Options:
A) 8.8 A and ${\tan ^{ - 1}}\left( {{{11} \over 6}} \right)
B) 88 A and ${\tan ^{ - 1}}\left( {{{11} \over 6}} \right)
C) 0.88 A and ${\tan ^{ - 1}}\left( {{{11} \over 6}} \right)
D) 8.8 A and ${\tan ^{ - 1}}\left( {{{6} \over 11}} \right)
190
MediumJEE Mains2021
A 10 $\Omega resistance is connected across 220V -$ 50 Hz AC supply. The time taken by the current to change from its maximum value to the rms value is :
Options:
A) 2.5 ms
B) 1.5 ms
C) 3.0 ms
D) 4.5 ms
191
EasyJEE Mains2021
In a circuit consisting of a capacitance and a generator with alternating emf Eg = Eg0 sin$\omega$t, VC and IC are the voltage and current. Correct phasor diagram for such circuit is
Options:
A)
B)
C)
D)
192
MediumJEE Mains2021
Match List - I with List - II List - I List - II (a) $\omega L > {1 \over {\omega C}} (i) Current is in phase with emf (b) \omega L = {1 \over {\omega C}} (ii) Current lags behind the applied emf (c) \omega L < {1 \over {\omega C}}$ (iii) Maximum current occurs (d) Resonant frequency (iv) Current leads the emf Choose the correct answer from the options given below
Options:
A) a(ii), b(i), c(iv), d(iii)
B) a(ii), b(i), c(iii), d(iv)
C) a(iii), b(i), c(iv), d(ii)
D) a(iv), b(iii), c(ii), d(i)
193
EasyJEE Mains2021
For a series LCR circuit with R = 100 $\Omega, L = 0.5 mH and C = 0.1 pF connected across 220V-$50 Hz AC supply, the phase angle between current and supplied voltage and the nature of the circuit is :
Options:
A) 0$^\circ$, resistive circuit
B) \approx 90^\circ$, predominantly inductive circuit
C) 0$^\circ$, resonance circuit
D) \approx 90^\circ$, predominantly capacitive circuit
194
MediumJEE Mains2021
AC voltage V(t) = 20 sin$\omegat of frequency 50 Hz is applied to a parallel plate capacitor. The separation between the plates is 2 mm and the area is 1 m2. The amplitude of the oscillating displacement current for the applied AC voltage is _________. [Take \varepsilon 0 = 8.85 \times 10-$12 F/m]
Options:
A) 55.58 $\mu$A
B) 21.14 $\mu$A
C) 27.79 $\mu$A
D) 83.37 $\mu$A
195
EasyJEE Mains2021
In a series LCR circuit, the inductive reactance (XL) is 10$\Omega and the capacitive reactance (XC) is 4\Omega. The resistance (R) in the circuit is 6\Omega$. The power factor of the circuit is :
Options:
A) {1 \over 2}
B) {{\sqrt 3 } \over 2}
C) {1 \over {\sqrt 2 }}
D) {1 \over {2\sqrt 2 }}
196
EasyJEE Mains2021
In a series LCR resonance circuit, if we change the resistance only, from a lower to higher value :
Options:
A) The bandwidth of resonance circuit will increase.
B) The resonance frequency will increase.
C) The quality factor will increase.
D) The quality factor and the resonance frequency will remain constant.
197
EasyJEE Mains2021
An AC source rated 220 V, 50 Hz is connected to a resistor. The time taken by the current to change from its maximum to the rms value is :
Options:
A) 2.5 ms
B) 25 ms
C) 2.5 s
D) 0.25 ms
198
EasyJEE Mains2021
Match List - I with List - II List - I List - II (a) Phase difference between current and voltage in a purely resistive AC circuit (i) ${\pi \over 2}; current leads voltage (b) Phase difference between current and voltage in a pure inductive AC circuit (ii) zero (c) Phase difference between current and voltage in a pure capacitive AC circuit (iii) {\pi \over 2}; current lags voltage (d) Phase difference between current and voltage in an LCR series circuit (iv) {\tan ^{ - 1}}\left( {{{{X_C} - {X_L}} \over R}} \right)$ Choose the most appropriate answer from the options given below :
Options:
A) (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv)
B) (a)-(i), (b)-(iii), (c)-(iv), (d)-(ii)
C) (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
D) (a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)
199
EasyJEE Mains2021
What happens to the inductive reactance and the current in a purely inductive circuit if the frequency is halved?
Options:
A) Both, inducting reactance and current will be doubled.
B) Inductive reactance will be doubled and current will be halved.
C) Both, inductive reactance and current will be halved.
D) Inductive reactance will be halved and current will be doubled.
200
MediumJEE Mains2021
An AC current is given by I = I1 sin$\omegat + I2 cos\omega$t. A hot wire ammeter will give a reading :
Options:
A) {{{I_1} + {I_2}} \over {\sqrt 2 }}
B) \sqrt {{{I_1^2 - I_2^2} \over 2}}
C) \sqrt {{{I_1^2 + I_2^2} \over 2}}
D) {{{I_1} + {I_2}} \over {2\sqrt 2 }}
201
EasyJEE Mains2021
For the given circuit, comment on the type of transformer used.
Options:
A) Auxiliary transformer
B) Step down transformer
C) Step-up transformer
D) Auto transformer
202
MediumJEE Mains2021
An RC circuit as shown in the figure is driven by a AC source generating a square wave. The output wave pattern monitored by CRO would look close to :
Options:
A)
B)
C)
D)
203
MediumJEE Mains2021
Find the peak current and resonant frequency of the following circuit (as shown in figure).
Options:
A) 2 A and 100 Hz
B) 2 A and 50 Hz
C) 0.2 A and 100 Hz
D) 0.2 A and 50 Hz
204
MediumJEE Mains2021
An alternating current is given by the equation i = i1 sin $\omegat + i2 cos \omega$t. The rms current will be :
Options:
A) {1 \over {\sqrt 2 }}{\left( {i_1^2 + i_2^2} \right)^{{1 \over 2}}}
B) {1 \over {\sqrt 2 }}({i_1} + {i_2})
C) {1 \over {\sqrt 2 }}{({i_1} + {i_2})^2}
D) {1 \over 2}{\left( {i_1^2 + i_2^2} \right)^{{1 \over 2}}}
205
MediumJEE Mains2021
An LCR circuit contains resistance of 110$\Omega and a supply of 220 V at 300 rad/s angular frequency. If only capacitance is removed from the circuit, current lags behind the voltage by 45^\circ. If on the other hand, only inductor is removed the current leads by 45^\circ$ with the applied voltage. The rms current flowing in the circuit will be :
Options:
A) 1 A
B) 2.5 A
C) 2 A
D) 1.5 A
206
EasyJEE Mains2021
Match List I with List II. List I List II (a) Rectifier (i) Used either for stepping up or stepping down the a.c. voltage (b) Stabilizer (ii) Used to convert a.c. voltage into d.c. voltage (c) Transformer (iii) Used to remove any ripple in the rectified output voltage (d) Filter (iv) Used for constant output voltage even when the input voltage or load current change Choose the correct answer from the options given below :
Options:
A) (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii)
B) (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
C) (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
D) (a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)
207
MediumJEE Mains2021
The angular frequency of alternating current in a L-C-R circuit is 100 rad/s. The components connected are shown in the figure. Find the value of inductance of the coil and capacity of condenser.
Options:
A) 0.8 H and 150 $\mu$F
B) 0.8 H and 250 $\mu$F
C) 1.33 H and 150 $\mu$F
D) 1.33 H and 250 $\mu$F
208
MediumJEE Mains2021
The current (i) at time t = 0 and t = $\infty $ respectively for the given circuit is :
Options:
A) {{18E} \over {55}},{{5E} \over {18}}
B) {{5E} \over {18}},{{18E} \over {55}}
C) {{5E} \over {18}},{{10E} \over {33}}
D) {{10E} \over {33}},{{5E} \over {18}}
209
MediumJEE Mains2020
An AC circuit has R= 100 $\Omega , C = 2 \mu $F and L = 80 mH, connected in series. The quality factor of the circuit is :
Options:
A) 20
B) 2
C) 0.5
D) 400
210
MediumJEE Mains2020
A series L-R circuit is connected to a battery of emf V. If the circuit is switched on at t = 0, then the time at which the energy stored in the inductor reaches $\left( {{1 \over n}} \right)$ times of its maximum value, is :
Options:
A) {L \over R}\ln \left( {{{\sqrt n } \over {\sqrt n + 1}}} \right)
B) {L \over R}\ln \left( {{{\sqrt n } \over {\sqrt n - 1}}} \right)
C) {L \over R}\ln \left( {{{\sqrt n + 1} \over {\sqrt n - 1}}} \right)
D) {L \over R}\ln \left( {{{\sqrt n - 1} \over {\sqrt n }}} \right)
211
MediumJEE Mains2020
A 750 Hz, 20 V (rms) source is connected to a resistance of 100 $\Omega , an inductance of 0.1803 H and a capacitance of 10 \mu $F all in series. The time in which the resistance (heat capacity 2 J/oC) will get heated by 10oC. (assume no loss of heat to the surroudnings) is close to :
Options:
A) 348 s
B) 418 s
C) 245 s
D) 365 s
212
MediumJEE Mains2020
An inductance coil has a reactance of 100 $\Omega $. When an AC signal of frequency 1000 Hz is applied to the coil, the applied voltage leads the current by 45o. The self-inductance of the coil is
Options:
A) 6.7 $ \times $ 10–7 H
B) 1.1 $ \times $ 10–1 H
C) 5.5 $ \times $ 10–5 H
D) 1.1 $ \times $ 10–2 H
213
MediumJEE Mains2020
In LC circuit the inductance L = 40 mH and capacitance C = 100 $\mu $F. If a voltage V(t) = 10sin(314t) is applied to the circuit, the current in the circuit is given as :
Options:
A) 0.52 cos 314 t
B) 5.2 cos 314 t
C) 0.52 sin 314 t
D) 10 cos 314 t
214
MediumJEE Mains2020
An emf of 20 V is applied at time t = 0 to a circuit containing in series 10 mH inductor and 5 $\Omega resistor. The ratio of the currents at time t = \infty $ and at t = 40 s is close to : (Take e2 = 7.389)
Options:
A) 1.06
B) 0.84
C) 1.15
D) 1.46
215
MediumJEE Mains2020
A LCR circuit behaves like a damped harmonic oscillator. Comparing it with a physical spring-mass damped oscillator having damping constant 'b', the correct equivalence would be:
Options:
A) L $ \leftrightarrow k, C \leftrightarrow b, R \leftrightarrow $ m
B) L $ \leftrightarrow m, C \leftrightarrow k, R \leftrightarrow $ b
C) L $ \leftrightarrow m, C \leftrightarrow {1 \over k}, R \leftrightarrow $ b
D) L $ \leftrightarrow {1 \over b}, C \leftrightarrow {1 \over m}, R \leftrightarrow {1 \over k}
216
MediumJEE Mains2019
Consider the LR circuit shown in the figure. If the switch S is closed at t = 0 then the amount of charge that passes through the battery between t = 0 and t = ${L \over R}$ is :
Options:
A) {{2.7EL} \over {{R^2}}}
B) {{EL} \over {2.7{R^2}}}
C) {{7.3EL} \over {{R^2}}}
D) {{EL} \over {7.3{R^2}}}
217
MediumJEE Mains2019
A coil of self inductance 10 mH and resistance 0.1 $\Omega is connected through a switch to a battery of internal resistance 0.9 \Omega $. After the switch is closed, the time taken for the current to attain 80% of the saturation value is: [take ln 5 = 1.6]
Options:
A) 0.324 s
B) 0.002 s
C) 0.103 s
D) 0.016 s
218
MediumJEE Mains2019
A transformer consisting of 300 turns in the primary and 150 turns in the secondary gives output power of 2.2 kW. If the current in the secondary coil is 10A, then the input voltage and current in the primary coil are :
Options:
A) 220 V and 20 A
B) 220 V and 10A
C) 440 V and 5A
D) 440 V and 20 A
219
MediumJEE Mains2019
A circuit connected to an ac source of emf e = e0sin(100t) with t in seconds, gives a phase difference of $\pi $/4 between the emf e and current i. Which of the following circuits will exhibit this ?
Options:
A) RC circuit with R = 1 k$\Omega $ and C = 1μF
B) RL circuit with R = 1k$\Omega $ and L = 1mH
C) RC circuit with R = 1k$\Omega $ and C = 10 μF
D) RL circuit with R = 1 k$\Omega $ and L = 10 mH
220
MediumJEE Mains2019
An alternating voltage v(t) = 220 sin 100 $\pi t volt is applied to a purely resistance load of 50\Omega $ . The time taken for the current to rise from half of the peak value to the peak value is :
Options:
A) 5 ms
B) 2.2 ms
C) 3.3 ms
D) 7.2 ms
221
MediumJEE Mains2019
In the above circuit, C = ${{\sqrt 3 } \over 2}\mu F, R2 = 20 \Omega , L = {{\sqrt 3 } \over {10}} H and R1 = 10 \Omega . Current in L-R1 path is I1 and in C-R2 path it is I2 . The voltage of A.C. source is given by, V = 200 {\sqrt 2 }$ sin (100 t) volts . The phase difference between I1 and I2 is :
Options:
A) 150o
B) 90o
C) 30o
D) 0o
222
MediumJEE Mains2019
In the figure shown, a circuit contains two identical resistors with resistance R = 5$\Omega $ and an inductance with L = 2mH. An ideal battery of 15 V is connected in the circuit. What will be the current through the battery long after the switch is closed ?
Options:
A) 6 A
B) 7.5 A
C) 3 A
D) 5.5 A
223
MediumJEE Mains2019
In the circuit shown, the switch S1 is closed at time t = 0 and the switch S2 is kept open. At some later time(t0), the switch S1 is opened and S2 is closed. The behavior of the current I as a function of time 't' is given by :
Options:
A)
B)
C)
D)
224
MediumJEE Mains2019
A series AC circuit containing an inductor (20 mH), a capacitor (120 $\mu F) and a resistor (60 \Omega $) is driven by an AC source of 24V/50 Hz. The energy dissipated in the circuit in 60 s is :
Options:
A) 5.65 $ \times $ 102J
B) 2.26 $ \times $ 103J
C) 5.17 $ \times $ 102 J
D) 3.39 $ \times $ 103 J
225
MediumJEE Mains2019
A power transmission line feeds input power at 2300 V to a srep down transformer with its primary windings having 4000 turns. The output power is delivered at 230 V by the transformer. If the current in the primary of the transformer is 5A and its efficiency is 90%, the output current would be :
Options:
A) 50 A
B) 45 A
C) 35 A
D) 25 A
226
MediumJEE Mains2018
A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns, giving the output power at 230 V. If the current in the primary of the transformer is 5 A, and its efficiency is 90%, the output current would be ;
Options:
A) 50 A
B) 45 A
C) 25 A
D) 20 A
227
MediumJEE Mains2018
For an RLC circuit driven with voltage of amplitude vm and frequency ${\omega _0} = {1 \over {\sqrt {LC} }}$ the current exhibits resonance. The quality factor, Q is given by :
Options:
A) {{CR} \over {{\omega _0}}}
B) {{{\omega _0}L} \over R}
C) {{{\omega _0}R} \over L}
D) {R \over {\left( {{\omega _0}C} \right)}}
228
MediumJEE Mains2018
In an a.c. circuit, the instantaneous e.m.f. and current are given by e = 100 sin 30 t i = 20 sin $\left( {30t - {\pi \over 4}} \right)$ In one cycle of a.c., the average power consumed by the circuit and the wattless current are, respectively
Options:
A) 50, 0
B) 50, 10
C) {{1000} \over {\sqrt 2 }},10
D) {{50} \over {\sqrt 2 }}
229
MediumJEE Mains2018
An ideal capacitor of capacitance $0.2\,\mu F is charged to a potential difference of 10 V. The charging battery is then disconnected. The capacitor is then connected to an ideal inductor of self inductance 0.5 mH. The current at a time when the potential difference across the capacitor is 5 V,$ is :
Options:
A) 0.34\,\,A
B) 0.25\,\,A
C) 0.17\,\,A
D) 0.15\,\,A
230
MediumJEE Mains2017
A sinusoidal voltage of peak value 283 V and angular frequency 320/s is applied to a series LCR circuit. Given that R=5 $\Omega , L=25 mH and C=1000 \mu $F. The total impedance, and phase difference between the voltage across the source and the current will respectively be :
Options:
A) 10 $\Omega and tan-1 \left( {{5 \over 3}} \right)
B) 7\,\Omega $ and 45o
C) 10\,\Omega and tan-1\left( {{8 \over 3}} \right)
D) 7\,\Omega and tan-1\left( {{5 \over 3}} \right)
231
MediumJEE Mains2016
A series LR circuit is connected to a voltage source with V(t) = V0 sin$\Omega t. After very large time, current I(t) behaves as (t0 >> {L \over R}$) :
Options:
A)
B)
C)
D)
232
MediumJEE Mains2016
An arc lamp requires a direct current of 10 A at 80 V to function. If it is connected to a 220 V (rms), 50 Hz AC supply, the series inductor needed for it to work is close to :
Options:
A) 0.044 H
B) 0.065 H
C) 80 H
D) 0.08 H
233
MediumJEE Mains2015
An $LCR circuit is equivalent to a damped pendulum. In an LCR circuit the capacitor is charged to {Q_0} and then connected to the L and R as shown below : If a student plots graphs of the square of maximum charge \left( {Q_{Max}^2} \right) on the capacitor with time(t) for two different values {L_1} and {L_2} \left( {{L_1} > {L_2}} \right) of L then which of the following represents this graph correctly ? \left( {plots\,\,are\,\,schematic\,\,and\,\,niot\,\,drawn\,\,to\,\,scale} \right)
Options:
A)
B)
C)
D)
234
MediumJEE Mains2015
An inductor $(L=0.03 H) and a resistor \left( {R = 0.15\,k\Omega } \right) are connected in series to a battery of 15V EMF in a circuit shown below. The key {K_1} has been kept closed for a long time. Then at t=0, {K_1} is opened and key {K_2} is closed simultaneously. At t=1 ms, the current in the circuit will be : \left( {{e^5} \cong 150} \right)
Options:
A) 6.7 mA
B) 0.67 mA
C) 100 mA
D) 67 mA
235
MediumJEE Mains2014
In the circuit shown here, the point $'C' is kept connected to point 'A' till the current flowing through the circuit becomes constant. Afterward, suddenly, point 'C' is disconnected from point 'A' and connected to point 'B' at time t=0. Ratio of the voltage across resistance and the inductor at t=L/R$ will be equal to :
Options:
A) {e \over {1 - e}}
B) 1
C) -1
D) {{1 - e} \over e}
236
MediumJEE Mains2013
In an $LCR circuit as shown below both switches are open initially. Now switch {S_1} is closed, {S_2} kept open. (q is charge on the capacitor and \tau =RC$ is Capacitance time constant). Which of the following statement is correct ?
Options:
A) Work done by the battery is half of the energy dissipated in the resistor
B) t = \,\tau ,\,q = CV/2
C) At $t = \,2\tau ,\,q = CV\left( {1 - {e^{ - 2}}} \right)
D) At $t = \,2\tau ,\,q = CV\left( {1 - {e^{ - 1}}} \right)
237
MediumJEE Mains2011
A resistor $'R' and 2\mu F capacitor in series is connected through a switch to 200 V direct supply. Across the capacitor is a neon bulb that lights up at 120 V. Calculate the value of R to make the bulb light up 5 s after the switch has been closed. \left( {{{\log }_{10}}2.5 = 0.4} \right)
Options:
A) 1.7 \times {10^5}\,\Omega
B) 2.7 \times {10^6}\,\Omega
C) 3.3 \times {10^7}\,\Omega
D) 1.3 \times {10^4}\,\Omega
238
MediumJEE Mains2011
A fully charged capacitor $C with initial charge {q_0} is connected to a coil of self inductance L at t=0.$ The time at which the energy is stored equally between the electric and the magnetic fields is :
Options:
A) {\pi \over 4}\sqrt {LC}
B) 2\pi \sqrt {LC}
C) \sqrt {LC}
D) \pi \sqrt {LC}
239
MediumJEE Mains2010
In a series $LCR circuit R = 200\Omega and the voltage and the frequency of the main supply is 220V and 50 Hz respectively. On taking out the capacitance from the circuit the current lags behind the voltage by {30^ \circ }. On taking out the inductor from the circuit the current leads the voltage by {30^ \circ }. The power dissipated in the LCR$ circuit is
Options:
A) 305 W
B) 210 W
C) zero W
D) 242 W
240
MediumJEE Mains2010
In the circuit shown below, the key $K is closed at t=0.$ The current through the battery is
Options:
A) {{V{R_1}{R_2}} \over {\sqrt {R_1^2 + R_2^2} }} at t=0 and {V \over {{R_2}}} at t = \infty
B) {V \over {{R_2}}} at \,t = 0 and {{V\left( {{R_1} + {R_2}} \right)} \over {{R_1}{R_2}}} at t = \infty
C) {V \over {{R_2}}} at \,t = 0 and {{V{R_1}{R_2}} \over {\sqrt {R_1^2 + R_2^2} }} at t = \infty
D) {{V\left( {{R_1} + {R_2}} \right)} \over {{R_1}{R_2}}} at t=0 and {V \over {{R_2}}} at t = \infty
241
MediumJEE Mains2009
An inductor of inductance $L=400 mH and resistors of resistance {R_1} = 2\Omega and {R_2} = 2\Omega are connected to a battery of emf 12 V as shown in the figure. The internal resistance of the battery is negligible. The switch S is closed at t=0. The potential drop across L$ as a function of time is :
Options:
A) {{12} \over t}{e^{ - 3t}}V
B) 6\left( {1 - {e^{ - t/0.2}}} \right)V
C) 12{e^{ - 5t}}V
D) 6{e^{ - 5t}}V
242
MediumJEE Mains2007
In an $a.c. circuit the voltage applied is E = {E_0}\,\sin \,\omega t. The resulting current in the circuit is I = {I_0}\sin \left( {\omega t - {\pi \over 2}} \right).$ The power consumption in the circuit is given by
Options:
A) P = \sqrt 2 {E_0}{I_0}
B) P = {{{E_0}{I_0}} \over {\sqrt 2 }}
C) P=zero
D) P = {{{E_0}{I_0}} \over 2}
243
MediumJEE Mains2006
In a series resonant $LCR circuit, the voltage across R is 100 volts and R = 1\,k\Omega with C = 2\mu F. The resonant frequency \omega is 200 rad/s. At resonance the voltage across L$ is
Options:
A) 2.5 \times {10^{ - 2}}V
B) 40 V
C) 250 V
D) 4 \times {10^{ - 3}}V
244
MediumJEE Mains2006
In an $AC generator, a coil with N turns, all of the same area A and total resistance R, rotates with frequency \omega in a magnetic field B. The maximum value of emf$ generated in the coil is
Options:
A) N.A.B.R.\omega
B) N.A.B
C) N.A.B.R.
D) N.A.B.\omega
245
MediumJEE Mains2005
The self inductance of the motor of an electric fan is $10 H. In order to impart maximum power at 50 Hz$, it should be connected to a capacitance of
Options:
A) 8\mu F
B) 4\mu F
C) 2\mu F
D) 1\mu F
246
MediumJEE Mains2005
A circuit has a resistance of $12 ohm and an impedance of 15 ohm$. The power factor of the circuit will be
Options:
A) 0.4
B) 0.8
C) 0.125
D) 1.25
247
MediumJEE Mains2005
The phase difference between the alternating current and $emf is {\pi \over 2}.$ Which of the following cannot be the constituent of the circuit?
Options:
A) R,L
B) C$ alone
C) L$ alone
D) L, C
248
MediumJEE Mains2004
In an $LCR series a.c. circuit, the voltage across each of the components, L,C and R is 50V. The voltage across the L.C$ combination will be :
Options:
A) 100V
B) 50\sqrt 2
C) 50 V
D) 0 V$ (zero)
249
MediumJEE Mains2004
In a $LCR circuit capacitance is changed from C to 2 C. For the resonant frequency to remain unchaged, the inductance should be changed from L$ to
Options:
A) L/2
B) 2L
C) 4L
D) L/4
250
MediumJEE Mains2004
Alternating current can not be measured by $D.C.$ ammeter because
Options:
A) Average value of current for complete cycle is zero
B) A.C.$ Changes direction
C) A.C. can not pass through D.C.$ Ammeter
D) D.C.$ Ammeter will get damaged.
251
MediumJEE Mains2003
The core of any transformer is laminated so as to
Options:
A) reduce the energy loss due to eddy currents
B) make it light weight
C) make it robust and strong
D) increase the secondary voltage
252
MediumJEE Mains2003
In an oscillating $LC circuit the maximum charge on the capacitor is Q$. The charge on the capacitor when the energy is stored equally between the electric and magnetic field is
Options:
A) {Q \over 2}
B) {Q \over {\sqrt 3 }}
C) {Q \over {\sqrt 2 }}
D) Q
253
MediumJEE Mains2002
In a transformer, number of turns in the primary coil are $140 and that in the secondary coil are 280. If current in primary coil is 4A,$ then that in the secondary coil is
Options:
A) 4A
B) 2A
C) 6A
D) 10A
254
MediumJEE Mains2002
The power factor of $AC circuit having resistance (R) and inductance (L) connected in series and an angular velocity \omega $ is
Options:
A) R/\omega L
B) R/{\left( {{R^2} + {\omega ^2}{L^2}} \right)^{1/2}}
C) \omega L/R
D) R/{\left( {{R^2} - {\omega ^2}{L^2}} \right)^{1/2}}
255
MediumMHT CET2025
In an LC circuit, angular frequency at resonance is \omega. The new angular frequency when inductance is made four times and capacitance is made eight times is
Options:
A) \frac{\omega}{2 \sqrt{2}}
B) \frac{\omega}{4 \sqrt{2}}
C) \frac{\omega}{4}
D) \frac{\omega}{\sqrt{2}}
256
MediumMHT CET2025
The value of alternating e.m.f. (E) in the given circuit is
Options:
A) 30 V
B) 60 V
C) 50 V
D) 110 V
257
MediumMHT CET2025
An inductor of \left(\frac{100}{\pi}\right) \mathrm{mH}, capacitor of capacitance \left(\frac{10^{-3}}{2 \pi}\right) \mathrm{F} and resistance of 10 \Omega are connected in series with an AC voltage source of 110 \mathrm{~V}, 50 \mathrm{~Hz} supply. The tangent of the phase angle ' \phi ' between voltage and current is
Options:
A) 4
B) 3
C) 2
D) 1
258
MediumMHT CET2025
\text { The frequency at resonance for the circuit is }
Options:
A) \frac{1}{4 \pi \sqrt{\mathrm{LC}}}
B) \frac{1}{2 \pi \sqrt{\mathrm{LC}}}
C) \frac{1}{\pi \sqrt{\mathrm{LC}}}
D) \frac{2}{\pi \sqrt{\mathrm{LC}}}
259
MediumMHT CET2025
In an a.c. circuit containing L, C, R in series the ratio of true power to apparent power is ( \mathrm{Z}= impedance of the circuit and R is the resistance)
Options:
A) \frac{\mathrm{Z}}{\mathrm{R}}
B) \tan \phi
C) \cot \phi
D) \frac{R}{Z}
260
MediumMHT CET2025
In series LCR circuit R =18 \Omega and impedance is 30 \Omega. An rms voltage 210 V is applied across the circuit. The true power consumed in AC circuit is nearly
Options:
A) 210 W
B) 400 W
C) 800 W
D) 900 W
261
MediumMHT CET2025
A resistor of 5 . \Omega, inductor of self inductance \left(\frac{2}{\pi^2}\right) \mathrm{H} and a capacitor of unknown capacity are connected in series to an a.c. source of 100 \mathrm{~V}, 50 \mathrm{~Hz} supply. When the voltage and current are in phase, the value of capacitance is
Options:
A) 10 \mu \mathrm{~F}
B) 20 \mu \mathrm{~F}
C) 40 \mu \mathrm{~F}
D) 50 \mu \mathrm{~F}
262
MediumMHT CET2025
\mathrm{L}, \mathrm{C} and R are connected in series to an a. c. source. Which one of the following is true? Phase relation between current and voltage is such that
Options:
A) both are out of phase with each other in ' R '.
B) both are in phase in ' L ' and out of phase in ' C '.
C) both are out of phase in ' L ' and in phase in 'C'.
D) both are out of phase in both ' C ' and ' L '.
263
MediumMHT CET2025
In series LCR circuit C =2 \mu \mathrm{~F}, \mathrm{~L}=5 \mathrm{mH} and \mathrm{R}=5 \Omega. The ratio of energy stored in the inductor to that in capacitor, when maximum current flows through the circuit is
Options:
A) 200: 1
B) 100: 1
C) 300: 1
D) 500: 1
264
MediumMHT CET2025
In an L R circuit, the value of L is \left(\frac{0.3}{\pi}\right) henry and the value of R is 40 \Omega, If in the circuit, an alternating e.m.f of 230 V at 50 cycles per second is connected, the impedance of the circuit and current will be respectively
Options:
A) 12.5 \Omega, 9.2 \mathrm{~A}
B) 46.4 \Omega, 6.4 \mathrm{~A}
C) 23.2 \Omega, 5 \mathrm{~A}
D) 50 \Omega, 4.6 \mathrm{~A}
265
MediumMHT CET2025
In an a.c. circuit, a resistance ' R ' is connected in series with an inductance ' L '. If phase angle between voltage and current is 45^{\circ}, the value of inductive reactance will be \left(\tan 45^{\circ}=1\right)
Options:
A) R
B) \frac{\mathrm{R}}{2}
C) \frac{\mathrm{R}}{4}
D) \frac{\mathrm{R}}{\sqrt{2}}
266
MediumMHT CET2025
An a.c. source of frequency ' f ' is connected to a circuit containing an inductance ' L ' and resistance ' R ' in series. The impedance of this circuit is
Options:
A) \sqrt{\mathrm{R}^2+2 \pi \mathrm{fL}^2}
B) \sqrt{\mathrm{R}^2+\mathrm{L}^2}
C) \mathrm{R}+2 \pi \mathrm{fL}
D) \sqrt{\mathrm{R}^2+4 \pi^2 \mathrm{f}^2 \mathrm{~L}^2}
267
MediumMHT CET2025
The reactance of a capacitor is \mathrm{X}_{\mathrm{C}}. If the frequency and the capacitance are doubled, then the new reactance will be
Options:
A) \frac{X_C}{2}
B) \mathrm{X}_{\mathrm{C}}
C) \frac{X_C}{4}
D) 2 X_C
268
MediumMHT CET2025
An a. c. voltage is applied to pure inductor. The current in the inductor
Options:
A) leads the voltage by \left(\frac{\pi}{4}\right)^c
B) leads the voltage by \left(\frac{\pi}{2}\right)^c
C) lags behind the voltage by \left(\frac{\pi}{2}\right)^c
D) lags behind the voltage by \left(\frac{3 \pi}{4}\right)^c
269
MediumMHT CET2025
The power factor of a CR circuit is \frac{1}{\sqrt{2}}, If the frequency of a.c. signal is halved, then the power factor of the circuit will become
Options:
A) \frac{1}{\sqrt{3}}
B) \frac{1}{\sqrt{5}}
C) \frac{1}{\sqrt{7}}
D) \frac{1}{\sqrt{11}}
270
MediumMHT CET2025
In LCR series circuit, when ' L ' is removed from the circuit, the phase difference between voltage and current in the circuit is \frac{\pi}{3}. If ' C ' is removed from the circuit instead of L then phase difference is again \frac{\pi}{3}. The power factor of the circuit is \left(\tan 60^{\circ}=\sqrt{3}\right)
Options:
A) \frac{\sqrt{3}}{2}
B) \sqrt{2}
C) \frac{1}{\sqrt{2}}
D) 1
271
MediumMHT CET2025
If the power factor changes from 0.5 to 0.25 because impedance changes from Z_1 to Z_2 then \mathrm{Z}_1=\mathrm{xZ}_2. The value of x is (Resistance remains constant)
Options:
A) 0.1
B) 0.5
C) 0.7
D) 0.4
272
MediumMHT CET2025
Same current is flowing in two different a.c. circuits. First circuit contains only inductance and second contains only capacitance. If the frequency of a.c. is increased in both circuits, the current will
Options:
A) increase in the first circuit and decrease in second.
B) increase in both circuits.
C) decrease in both circuits.
D) decrease in first circuit and increase in second.
273
MediumMHT CET2025
An a. c. source is connected across a pure inductor. Which one of the following figures shows the correct phase relation between the current and e.m.f.?
Options:
A) D
B) B
C) A
D) C
274
MediumMHT CET2025
In an a.c. circuit with pure capacitance ' C ' and a.c. source E=E_0 \sin \omega t, the equation of instantaneous current is given by
Options:
A) \mathrm{I}=\mathrm{E}_0 \omega \mathrm{c} \sin (\omega \mathrm{t})
B) I=E_0 \omega c \sin \left(\omega t+\frac{\pi}{2}\right)
C) \mathrm{I}=\frac{\mathrm{E}_0}{\omega \mathrm{c}} \sin (\omega \mathrm{t})
D) \mathrm{I}=\frac{\mathrm{E}_0}{\omega \mathrm{c}} \sin \left(\omega \mathrm{t}+\frac{\pi}{2}\right)
275
MediumMHT CET2025
A current of 5 A is flowing at 220 V in a primary coil of a transformer. If the voltage produced in the secondary coil is 2200 V and 50 \% of power is lost, then the current in the secondary coil will be
Options:
A) 2.5 A
B) 5 A
C) 0.25 A
D) \quad 0.025 \mathrm{~A}
276
MediumMHT CET2025
Figure shows the combination of inductances and capacitances. Resonant frequency of the \mathrm{L}-\mathrm{C} circuit is
Options:
A) \frac{1}{2 \pi \sqrt{\mathrm{LC}}}
B) \frac{1}{3 \pi \sqrt{\mathrm{LC}}}
C) \frac{1}{4 \pi \sqrt{\mathrm{LC}}}
D) \frac{1}{6 \pi \sqrt{\mathrm{LC}}}.
277
MediumMHT CET2025
An alternating e.m.f. is given by e=e_0 \sin \omega t. In how much time the e.m.f. will have half its maximum value, if e starts from zero ? $ \left(\mathrm{T}=\text { Time Period, } \sin 30^{\circ}=\frac{1}{2}\right)
Options:
A) \frac{\mathrm{T}}{8}
B) \frac{\mathrm{T}}{4}
C) \frac{T}{12}
D) \frac{T}{16}
278
MediumMHT CET2025
A coil has inductance 2 H . The ratio of its reactance when it is connected first to an a.c. source and then to a d.c. source is
Options:
A) -1
B) zero
C) \infty
D) +1
279
MediumMHT CET2025
When a capacitor is connected in series LR circuit, the alternating current flowing in the circuit
Options:
A) remains constant
B) increases
C) decreases
D) is zero
280
MediumMHT CET2025
When alternating current is passed through \mathrm{L}-\mathrm{R} series circuit, the power factor is \frac{\sqrt{3}}{2} and \mathrm{R}=50 \Omega, then the value of L is $ \left[\cos \frac{\pi}{6}=\frac{\sqrt{3}}{2}, \sin \frac{\pi}{6}=\frac{1}{2}, \tan \frac{\pi}{6}=\frac{1}{\sqrt{3}}\right]
Options:
A) \frac{1}{2} \pi
B) \frac{\sqrt{3}}{2} \pi
C) \frac{1}{2 \sqrt{3} \pi}
D) \frac{1}{\sqrt{3} \pi}
281
MediumMHT CET2025
An a.c. e.m.f. of peak value 230 V and frequency 50 Hz is connected to a circuit with \mathrm{R}=11.5 \Omega, \mathrm{~L}=2.5 \mathrm{H} and a capacitor all in series. The value of capacitance is ' C ' for the current in the circuit to be maximum. The value of ' C ' and maximum current are respectively ( \pi^2=10 )
Options:
A) 4 \mu \mathrm{~F}, 20 \mathrm{~A}
B) 5 \mu \mathrm{~F}, 10 \mathrm{~A}
C) 2 \mu \mathrm{~F}, 20 \mathrm{~A}
D) 8 \mu \mathrm{~F}, 12 \mathrm{~A}
282
MediumMHT CET2025
An ideal inductor of \left(\frac{1}{\pi}\right) \mathrm{H} is connected in series with a 300 \Omega resistor. If a 20 \mathrm{~V}, 200 \mathrm{~Hz} alternating source is connected across the combination, the phase difference between the voltage and current is
Options:
A) \tan ^{-1}\left(\frac{3}{4}\right)
B) \tan ^{-1}\left(\frac{4}{3}\right)
C) \tan ^{-1}\left(\frac{5}{4}\right)
D) \tan ^{-1}\left(\frac{4}{5}\right)
283
MediumMHT CET2025
An alternating e.m.f. having voltage \mathrm{V}=\mathrm{V}_0 \sin \omega t is applied to a series L-C-R circuit. Given : \left|X_L-X_C\right|=R. The r.m.s. value of potential difference across capacitor will be
Options:
A) \quad \mathrm{V}_0 \mathrm{R} \omega \mathrm{C}
B) \frac{\mathrm{V}_0}{\mathrm{R} \omega \mathrm{C}}
C) \frac{\mathrm{V}_0}{2 \mathrm{R} \omega \mathrm{C}}
D) \frac{\mathrm{V}_0}{\sqrt{2} \mathrm{R} \omega \mathrm{C}}
284
MediumMHT CET2025
In an electrical circuit ' R ', ' L ', ' C ' and an a.c. voltage source are all connected in series. When ' L ' is removed from the circuit, the phase difference between the voltage and the current in the circuit is \frac{\pi}{3}. If instead ' C ' is removed from the circuit, the phase difference is again \frac{\pi}{3}. The power factor of the circuit is \left(\tan \frac{\pi}{3}=\sqrt{3}\right)
Options:
A) \frac{\sqrt{3}}{2}
B) \frac{1}{2}
C) \frac{1}{\sqrt{2}}
D) 1
285
MediumMHT CET2025
In series LCR resonant circuit, R =800 \Omega, \mathrm{C}=2 \mu \mathrm{~F} and voltage across resistance is 200 V . The angular frequency is 250 \mathrm{rad} / \mathrm{s}. At resonance, the voltage across the inductance is
Options:
A) 400 V
B) 250 V
C) 1000 V
D) 500 V
286
MediumMHT CET2025
If maximum energy is stored in a capacitor at \mathrm{t}=0 then the time after which, current in the circuit will be maximum is
Options:
A) \pi \times 10^{-3} \mathrm{~s}
B) 2 \pi \times 10^{-3} \mathrm{~s}
C) 2 \pi \times 10^{-4} \mathrm{~s}
D) \pi \times 10^{-4} \mathrm{~s}
287
MediumMHT CET2025
In LCR series circuit, R = 18 \Omega and impedance 33 \Omega. An r.m.s. voltage of 220 V is applied across the circuit. The true power consumed in a.c. circuit is
Options:
A) 400 W
B) 600 W
C) 800 W
D) 900 W
288
MediumMHT CET2025
An a.c. e.m.f. of peak value =230 \mathrm{~V} and frequency 50 Hz is connected to a circuit with \mathrm{R}=11.5 \Omega, \mathrm{~L}=2.5 \mathrm{H} and a capacitor all in series. The value of capacitance is ' C ' for the current in the circuit to be maximum. The value of C and maximum current are respectively \left(\pi^2=10\right).
Options:
A) 2 \mu \mathrm{~F}, 10 \mathrm{~A}
B) 4 \mu \mathrm{~F}, 20 \mathrm{~A}
C) 6 \mu \mathrm{~F}, 10 \mathrm{~A}
D) 8 \mu \mathrm{~F}, 20 \mathrm{~A}
289
MediumMHT CET2025
An e.m.f. e=E_0 \cos \omega t is applied to a circuit containing L, C and R in series where X_L=3 R and \mathrm{X}_{\mathrm{C}}=\mathrm{R}. The average power dissipated in the circuit is
Options:
A) \frac{E_0^2}{5 R}
B) \frac{E_0^2}{10 R}
C) \frac{\mathrm{E}_0^2}{15 \mathrm{R}}
D) \frac{E_0^2}{20 R}
290
MediumMHT CET2025
An ideal transformer converts 220 a.c. to 3.3 kV a.c. to transmit a power of 4.4 kW . If primary coil has 600 turns then alternating current in secondary coil is
Options:
A) \frac{5}{3} \mathrm{~A}
B) \frac{1}{4} \mathrm{~A}
C) \frac{4}{3} \mathrm{~A}
D) \frac{2}{3} \mathrm{~A}
291
MediumMHT CET2025
A coil of self-inductance L is connected in series with a bulb and an a. c. source. Brightness of the bulb decreases when
Options:
A) an iron rod is inserted in the coil.
B) frequency of a.c. source is decreased.
C) number of turns in the coil is reduced.
D) a capacitance of reactance \left(\mathrm{X}_{\mathrm{C}}-\mathrm{X}_{\mathrm{L}}\right) is included in the same circuit.
292
MediumMHT CET2025
A 20 \Omega resistance, 10 mH inductance coil and 15 \mu \mathrm{~F} capacitor are joined in series. When a suitable frequency alternating current source is joined to this combination, the circuit resonates. If the resistance is made \frac{1}{3} \mathrm{rd}, the resonant frequency
Options:
A) remains unchanged.
B) is doubled.
C) is quadrupled.
D) is halved.
293
MediumMHT CET2025
A resistance of 200 \Omega and an inductor of \frac{1}{2 \pi} \mathrm{H} are connected in series to a.c. voltage of 40 V and 100 Hz frequency. The phase angle between the voltage and current is
Options:
A) \tan ^{-1}(1 / 5)
B) \tan ^{-1}(1 / 4)
C) \tan ^{-1}(1 / 3)
D) \tan ^{-1}(0.5)
294
MediumMHT CET2025
A coil of resistance 450 \Omega and self-inductance 1.5 henry is connected to an a.c. source of frequency \frac{150}{\pi} \mathrm{~Hz}. The phase difference between voltage and current is
Options:
A) \tan ^{-1}(0.5)
B) \tan ^{-1}(1)
C) \tan ^{-1}(1.5)
D) \tan ^{-1}(2.0)
295
MediumMHT CET2025
In an L-R circuit, the inductive reactance is equal to \sqrt{3} times the resistance ' R ' of the circuit. An e.1n.f. \mathrm{E}=\mathrm{E}_0 \sin (\omega \mathrm{t}) is applied to the circuit. The power consumed in the circuit is
Options:
A) \frac{\mathrm{E}_0^2}{4 \mathrm{R}}
B) \frac{E_0^2}{6 R}
C) \frac{\mathrm{E}_0^2}{8 \mathrm{R}}
D) \frac{E_0^2}{12 R}
296
MediumMHT CET2025
An a.c. source is applied to a series LR circuit with \mathrm{X}_{\mathrm{L}}=3 \mathrm{R} and power factor is \mathrm{X}_1. Now a capacitor with \mathrm{X}_{\mathrm{c}}=\mathrm{R} is added in series to LR circuit and the power factor is \mathrm{X}_2. The ratio \mathrm{X}_1 to \mathrm{X}_2 is
Options:
A) 1: 2
B) 2: 1
C) 1: \sqrt{2}
D) \sqrt{2}: 1
297
MediumMHT CET2025
A series LCR circuit is connected to an a.c. source of 230 \mathrm{~V}, 50 \mathrm{~Hz}. The circuit contains resistance of 80 \Omega an inductor having inductive reactance 70 \Omega and a capacitor of capacitive reactance 130 \Omega. The power factor of the circuit is x. The value of x is
Options:
A) 0.4
B) 0.8
C) 0.6
D) 0.9
298
MediumMHT CET2025
An alternating voltage \mathrm{E}=100 \sqrt{2} \sin (50 \mathrm{t}) is connected to a 2 \mu \mathrm{~F} capacitor through an a.c. ammeter. The ammeter reading will be
Options:
A) 10 mA
B) 5 mA
C) 20 mA
D) 30 mA
299
MediumMHT CET2025
The instantaneous value of current in an a.c. circuit is I=3 \sin \left(50 \pi t+\frac{\pi}{4}\right) \mathrm{A}. The current will be maximum for the first time at
Options:
A) \frac{1}{50} \mathrm{~s}
B) \frac{1}{100} \mathrm{~s}
C) \frac{1}{200} \mathrm{~s}
D) \frac{1}{600} \mathrm{~s}
300
MediumMHT CET2024
An inductance of 2 mH , a condenser of 20 \mu \mathrm{~F} and a resistance of 50 \Omega are connected in series to an a.c. source. The reactance of inductor and condenser are same. The reactance of either of them will be
Options:
A) 100 \Omega
B) 50 \Omega
C) 40 \Omega
D) 10 \Omega
301
MediumMHT CET2024
In an L C R circuit, if ' V ' is the effective value of the applied voltage, V_R is the voltage across ' R ', ' \mathrm{V}_{\mathrm{L}} ' and ' \mathrm{V}_{\mathrm{C}} ' is the effective voltage across ' L ' and ' C ' respectively then
Options:
A) \mathrm{V}=\mathrm{V}_{\mathrm{R}}+\mathrm{V}_{\mathrm{L}}+\mathrm{V}_{\mathrm{C}}
B) \mathrm{V}^2=\mathrm{V}_{\mathrm{R}}^2+\mathrm{V}_{\mathrm{L}}^2+\mathrm{V}_{\mathrm{C}}^2
C) \mathrm{V}^2=\mathrm{V}_{\mathrm{R}}^2+\left(\mathrm{V}_{\mathrm{L}}-\mathrm{V}_{\mathrm{c}}\right)^2
D) \mathrm{V}^2=\mathrm{V}_{\mathrm{L}}^2+\left(\mathrm{V}_{\mathrm{R}}-\mathrm{V}_{\mathrm{C}}\right)^2
302
MediumMHT CET2024
A light bulb connected in series with a capacitor and an a.c. source is glowing with a certain brightness. On reducing the capacity of capacitance and frequency of source, the brightness of the lamp (respectively)
Options:
A) is reduced, is increased
B) is reduced, is reduced
C) is increased, is reduced
D) is increased, is increased
303
MediumMHT CET2024
If a transformer of an audio amplifier has output impedance 8000 \Omega and the speaker has input impedance 8 \Omega, the primary and secondary turns of this transformer connected between the output of amplifier and to loudspeaker should have the ratio
Options:
A) 1000: 1
B) 100: 1
C) 1: 32
D) 32: 1
304
MediumMHT CET2024
In LCR series circuit, an alternating e.m.f. 'e' and current ' i ' are given by equations \mathrm{e}=160 \sin (100 \mathrm{t}) Volt and \mathrm{i}=250 \sin \left(100 \mathrm{t}+\frac{\pi}{3}\right) \mathrm{mA}. The average power dissipated in the circuit is
Options:
A) 2.5 W
B) 4.0 W
C) 10 W
D) 100 W
305
MediumMHT CET2024
An electric lamp connected in series with a capacitor and an a.c. source is glowing with certain brightness. On increasing the value of capacitance the brightness of the lamp
Options:
A) is increased.
B) is decreased.
C) remains the same.
D) becomes zero.
306
MediumMHT CET2024
The alternating voltage is given by \mathrm{v}=\mathrm{v}_0 \sin \left(\omega \mathrm{t}+\frac{\pi}{3}\right) when will be the voltage maximum for first time?
Options:
A) \frac{\mathrm{T}}{6}
B) \frac{\mathrm{T}}{3}
C) \frac{T}{2}
D) \frac{\mathrm{T}}{12}
307
MediumMHT CET2024
The core used in transformers are laminated to
Options:
A) increase the magnetic field.
B) increase the level of the magnetic saturation of the core.
C) reduce the residual magnetism in the core.
D) reduce eddy current losses in the core.
308
MediumMHT CET2024
A coil has inductance H . The ratio of its reactance when it is connected first to an a.c. source and then to d.c. source is
Options:
A) \infty
B) zero
C) one
D) two
309
MediumMHT CET2024
A resistor of 50 \Omega, inductor of self inductance \left(\frac{3}{\pi^2}\right) \mathrm{H} and a capacitor of unknown capacity are connected in series to an a.c. source of 100 V and 50 Hz . When the voltage and current are in phase, the value of capacitance is (nearly)
Options:
A) 0.66 \times 10^{-4} \mathrm{~F}
B) 0.33 \times 10^{-4} \mathrm{~F}
C) 0.66 \times 10^{-2} \mathrm{~F}
D) 0.33 \times 10^{-2} \mathrm{~F}
310
MediumMHT CET2024
Which one of the following graph represent correctly the variation of impedance (\mathrm{Z}) of a series LCR circuit with the frequency (v) of applied a.c.?
Options:
A) A
B) B
C) C
D) D
311
MediumMHT CET2024
When a coil is connected to a d.c. source of e.m.f. 12 volt; then the current of 4 A flows in it . If the same coil is connected to a 12 volt, 50 Hz a.c. source, then the current flowing in it is 2.4 A . Then self-inductance of the coil will be
Options:
A) 48 H
B) 12 H
C) \frac{4}{\pi} \times 10^{-2} \mathrm{H}
D) \frac{8}{\pi} \times 10^{-2} \mathrm{H}
312
MediumMHT CET2024
In an a.c. circuit, the reactance of a coil is \sqrt{3} times its resistance. The phase difference between the voltage across the coil to the current through the coil will be
Options:
A) \tan ^{-1}(0)
B) \tan ^{-1} \frac{1}{\sqrt{3}}
C) \tan ^{-1}(1)
D) \tan ^{-1}(\sqrt{3})
313
MediumMHT CET2024
A series \mathrm{L}-\mathrm{C}-\mathrm{R} circuit containing a resistance ' R ' has angular frequency ' \omega '. At resonance the voltage across resistance and inductor are ' V_R ' and ' \mathrm{V}_{\mathrm{L}} ' respectively, then value of capacitance will be
Options:
A) \frac{V_R}{V_L \omega R}
B) \frac{V_L}{V_R R \omega^2}
C) \frac{V_R}{V_L R \omega^2}
D) \frac{V_L R}{V_R \omega}
314
MediumMHT CET2024
Alternating current of peak value \left(\frac{2}{\pi}\right) A flows through the primary coil of a transformer. The coefficient of mutual inductance between primary and secondary coils is 1 H . The peak e.m.f. induced in secondary coil (Frequency of a.c. =50 \mathrm{~Hz} )
Options:
A) 50 V
B) 100 V
C) 150 V
D) 200 V
315
MediumMHT CET2024
When 100 V d.c. is applied across a solenoid, a current of 1 A flows in it. When 100 a.c. is applied across it, the current drops to 0.5 A. If the frequency is 50 Hz , the impedance and inductance is
Options:
A) 200 \Omega, \sqrt{3} / \pi \mathrm{H}
B) 100 \Omega, \sqrt{3} \mathrm{H}
C) 200 \Omega, 1 \mathrm{H}
D) 100 \Omega, 1 \mathrm{H}
316
MediumMHT CET2024
A 1 \mu \mathrm{~F} capacitor is charged to 50 V and is then discharged through 10 mH inductor of negligible resistance. The maximum current in the inductor is
Options:
A) 0.5 A
B) 1.5 A
C) 1 A
D) 0.15 A
317
MediumMHT CET2024
In LCR resonant circuit, the current and voltage have phase difference
Options:
A) \frac{\pi}{4}
B) \frac{\pi}{2}
C) -\frac{\pi}{2}
D) zero
318
MediumMHT CET2024
An inductance of \frac{300}{\pi} \mathrm{mH}, a capacitance of \frac{1}{\pi} \mathrm{mF} and a resistance of 20 \Omega are connected in series with an a.c. source of 240 \mathrm{~V}, 50 \mathrm{~Hz}. The phase angle of the circuit is
Options:
A) \tan ^{-1}(0)
B) \tan ^{-1}\left(\frac{1}{\sqrt{3}}\right)
C) \tan ^{-1}(1)
D) \tan ^{-1}(\sqrt{3})
319
MediumMHT CET2024
With an alternating voltage source frequency ' f ', inductor ' L ', capacitor ' C ' and resistance ' R ' are connected in series. The voltage leads the current by 45^{\circ}. The value of ' L ' is \left(\tan 45^{\circ}=1\right)
Options:
A) \left(\frac{1+2 \pi \mathrm{fCR}}{4 \pi^2 \mathrm{f}^2 \mathrm{C}}\right)
B) \left(\frac{1-2 \pi f C R}{4 \pi^2 \mathrm{f}^2 \mathrm{C}}\right)
C) \left(\frac{4 \pi^2 \mathrm{f}^2 \mathrm{C}}{1+2 \pi \mathrm{fCR}}\right)
D) \left(\frac{4 \pi^2 \mathrm{f}^2 \mathrm{C}}{1-2 \pi \mathrm{fCR}}\right)
320
MediumMHT CET2024
With gradual increase in frequency of an a.c. supply, the impedance of an LCR series circuit
Options:
A) increases.
B) decreases.
C) remains constant
D) first decreases, becomes minimum and then increases.
321
MediumMHT CET2024
An a.c. voltage source \mathrm{V}=\mathrm{V}_0 \sin \omega \mathrm{t} is connected across resistance ' R ' and capacitance ' C ' in series. It is given that R=\frac{1}{\omega c} and the peak current is \mathrm{I}_0. If the angular frequency of the voltage source is changed to \left(\frac{\omega}{\sqrt{3}}\right), then the new peak current in the circuit is
Options:
A) \frac{\mathrm{I}_0}{2}
B) \frac{\mathrm{I}_0}{\sqrt{2}}
C) \sqrt{2} \mathrm{I}_0
D) \sqrt{3} \mathrm{I}_0
322
MediumMHT CET2024
A transformer has 120 turns in the primary coil and carries 5 A current. Input power is one kilowatt. To have 560 V output, the number of turns in secondary coil will be
Options:
A) 168
B) 200
C) 336
D) 400
323
MediumMHT CET2024
In series LCR circuit, 'R' represents resistance of electric bulb. If the frequency of a.c. supply is doubled, the value of inductance ' L ' and capacitance 'C' should be
Options:
A) both doubled.
B) made four times.
C) made eight times.
D) both halved simultaneously.
324
MediumMHT CET2024
For the series L C R circuit, R=\frac{X_L}{2}=2 \mathrm{X}_{\mathrm{c}}. The impedance of the circuit and the phase difference between V and I will be
Options:
A) \frac{\sqrt{5}}{2} \mathrm{R}, \tan ^{-1}\left(\frac{1}{2}\right)
B) \frac{\sqrt{13}}{2} R, \tan ^{-1}\left(\frac{3}{2}\right)
C) \sqrt{5} R, \tan ^{-1}(1)
D) \sqrt{13} \mathrm{R}, \tan ^{-1}(2)
325
MediumMHT CET2024
An e.m.f. E=E_0 \cos \omega t is applied to the L-R circuit. The inductive reactance is equal to the resistance ' R ' of the circuit. The power consumed in the circuit is
Options:
A) \frac{E_0^2}{\sqrt{2} R}
B) \frac{E_0^2}{2 R}
C) \frac{E_0^2}{4 R}
D) \frac{E_0^2}{R}
326
MediumMHT CET2024
A series resonant circuit consists of inductor ' L ' of negligible resistance and a capacitor ' C ' which produces resonant frequency ' f '. If L is changed to 3 L and ' C ' is changed to 6 C , the resonant frequency will become.
Options:
A) \frac{\mathrm{f}}{6}
B) \frac{\mathrm{f}}{3}
C) \frac{\mathrm{f}}{2 \sqrt{2}}
D) \frac{\mathrm{f}}{3 \sqrt{2}}
327
MediumMHT CET2024
The inductive reactance of a coil is ' R ' \Omega. If inductance of a coil is tripled and frequency of a.c supply is also tripled, then new inductive reactance will be
Options:
A) \frac{\mathrm{R}}{9}
B) \frac{\mathrm{R}}{3}
C) \mathrm{3 R}
D) \mathrm{9 R}
328
MediumMHT CET2024
An e.m.f. E=E_0 \cos \omega t is applied to circuit containing L and R in series. If \mathrm{X}_{\mathrm{L}}=2 \mathrm{R}, then the power dissipated in the circuit is
Options:
A) \frac{\mathrm{E}_0{ }^2}{12 \mathrm{R}}
B) \frac{\mathrm{E}_0{ }^2}{10 \mathrm{R}}
C) \frac{\mathrm{E}_0{ }^2}{8 \mathrm{R}}
D) \frac{\mathrm{E}_0{ }^2}{6 \mathrm{R}}
329
MediumMHT CET2024
When a capacitor is connected in series LR circuit, the alternating current flowing in the circuit
Options:
A) is zero.
B) remains constant.
C) increases.
D) decreases.
330
MediumMHT CET2024
Average power associated with an ideal inductor and ideal capacitor over a complete cycle of a.c. is respectively
Options:
A) zero, one
B) one, zero
C) zero, zero
D) one, one
331
MediumMHT CET2024
LC series resonant circuit produces resonant frequency ' f '. If ' L ' is tripled and ' C ' is increased by 3 C, the resonant frequency will be
Options:
A) \frac{\mathrm{f}}{3}
B) \frac{\mathrm{f}}{2 \sqrt{3}}
C) \mathrm{6 f}
D) \frac{\mathrm{f}}{2 \sqrt{2}}
332
MediumMHT CET2024
When a capacitor is connected in series LR circuit, the alternating current flowing in the circuit
Options:
A) is zero.
B) increases.
C) decreases.
D) remain constant.
333
MediumMHT CET2024
An alternating current is given by \mathrm{I}=100 \sin (50 \pi \mathrm{t}). How many times will the current become zero in one second?
Options:
A) 50 times
B) 25 times
C) 40 times
D) 100 times
334
MediumMHT CET2024
A coil of self inductance L is connected in series with a bulb B and an a.c. source. Brightness of the bulb decreases when
Options:
A) frequency of a.c. source is decreased.
B) number of turns in the coil is reduced.
C) a capacitance of reactance \left(\mathrm{X}_{\mathrm{L}}-\mathrm{X}_{\mathrm{C}}\right) is included in the same circuit.
D) an iron rod is inserted in the coil.
335
MediumMHT CET2024
In series LCR resonant circuit, the capacitance is changed from C to 3 C . To obtain the same resonant frequency, the inductance should be changed from L to
Options:
A) \frac{\mathrm{L}}{3}
B) \frac{\mathrm{L}}{2}
C) \frac{\mathrm{L}}{\sqrt{3}}
D) \mathrm{3 L}
336
MediumMHT CET2024
For the given figure, choose the correct option.
Options:
A) The r.m.s. current in circuit (B) can never be greater than that in circuit (A)
B) The r.m.s. current in circuit (A) is always equal to that in circuit (B)
C) The r.m.s. current in circuit (B) can be greater than in circuit (A)
D) At resonance, current in (B) is less than that in circuit (A)
337
MediumMHT CET2024
In LCR series circuit if the frequency is increased, the impedance of the circuit
Options:
A) increases
B) decreases
C) either increases or decreases
D) first decreases then become minimum and then increases.
338
MediumMHT CET2024
An inductor of inductance 2 \mu \mathrm{H} is connected in series with a resistance, a variable capacitor and an a.c. source of frequency 5 kHz . The value of capacitance for which maximum current is drawn into the circuit is \frac{1}{\mathrm{x}} \mathrm{F}, where the value of ' x ' is (Take \pi^2=10)
Options:
A) 500
B) 1000
C) 2000
D) 4000
339
MediumMHT CET2024
When 80 volt d.c. is applied across a solenoid, a current of 0.8 A flows in it. When 80 volt a.c. is applied across the same solenoid, the current becomes 0.4 A . If the frequency of a.c. source is 50 Hz , the impedance and inductance of the solenoid is nearly
Options:
A) 200 \Omega, 0.55 \mathrm{H}
B) 100 \Omega, 0.8 \mathrm{H}
C) 300 \Omega, 1.2 \mathrm{H}
D) 200 \Omega, 1.5 \mathrm{H}
340
MediumMHT CET2024
A transformer is used to set up an alternating e.m.f. of 220 V to 4.4 kV to transmit 6.6 kW of power. The primary coil has 1000 turns. The current rating of the secondary coil is (Transformer is ideal)
Options:
A) 0.8 A
B) 1.2 A
C) 1.5 A
D) 1.8 A
341
MediumMHT CET2024
A series LCR circuit containing a resistance ' R ' has angular frequency ' \omega '. At resonance the voltage across resistance and inductor are ' \mathrm{V}_{\mathrm{R}} ' and ' V_L ' respectively, then value of inductance ' L ' will be
Options:
A) \frac{V_R R}{V_L \omega}
B) \frac{V_L}{V_R R \omega}
C) \frac{V_R \omega}{V_L R}
D) \frac{\mathrm{V}_{\mathrm{L}} \mathrm{R}}{\mathrm{V}_{\mathrm{R}} \omega}
342
MediumMHT CET2024
A 42 mH inductor is connected to 200 \mathrm{~V}, 50 \mathrm{~Hz} a.c. supply. The r.m.s. value of current in the circuit will be nearly [ Take \pi=\frac{22}{7} ]
Options:
A) 15.15 \mathrm{~A}
B) 9.15 A
C) 8.15 A
D) 6 . 15 \mathrm{~A}
343
MediumMHT CET2024
An alternating voltage \mathrm{v}=200 \sqrt{2} \sin (100 \mathrm{t}) is connected to a 1 \mu \mathrm{~F} capacitor through an a. c. ammeter. The reading of the ammeter shall be
Options:
A) 10 mA
B) 20 mA
C) 40 mA
D) 80 mA
344
MediumMHT CET2024
Three inductances are connected as shown in figure. The equivalent inductance is
Options:
A) \mathrm{\frac{L}{4}}
B) \frac{5}{4} \mathrm{~L}
C) \frac{7}{4} \mathrm{~L}
D) \mathrm{L}
345
MediumMHT CET2024
In an A C circuit E=200 \sin (50 t) volt and \mathrm{I}=100 \sin \left(50 \mathrm{t}+\frac{\pi}{3}\right) \mathrm{mA}. The power dissipated in the circuit is $\binom{\sin 30^{\circ}=\cos 60^{\circ}=0.5}{\sin 60^{\circ}=\cos 30^{\circ}=\sqrt{3} / 2}
Options:
A) 20 watt
B) 15 watt
C) 10 watt
D) 5 watt
346
MediumMHT CET2024
A transformer having efficiency 90 \% is working on 200 V and 3 kw power supply. If the current in the secondary coil is 6 A , the voltage across the secondary coil and the current in the primary coil are respectively
Options:
A) 300 \mathrm{~V}, 15 \mathrm{~A}
B) 450 \mathrm{~V}, 15 \mathrm{~A}
C) 450 \mathrm{~V}, 13 \cdot 5 \mathrm{~A}
D) 600 \mathrm{~V}, 15 \mathrm{~A}
347
MediumMHT CET2024
An inductance coil has a resistance of 80 \Omega. When on AC signal of frequency 480 Hz is applied to the coil, the voltage leads the current by 45^{\circ}. The inductance of the coil in henry is \left[\sin 45^{\circ}=\cos 45^{\circ}=1 / \sqrt{2}\right]
Options:
A) \frac{1}{24 \pi}
B) \frac{\pi}{20}
C) \frac{\pi}{40}
D) \frac{1}{12 \pi}
348
MediumMHT CET2024
\mathrm{L}=2 \mathrm{H}, \mathrm{C}=5 \mathrm{mF} and \mathrm{R}=12 \Omega are connected in series to an a.c. generator of frequency 50 Hz . Then
Options:
A) at resonance, impedance of the circuit is zero.
B) at resonance, impedance of the circuit is 12 \Omega.
C) the resonant frequency of the circuit is 1 / 2 \pi.
D) the inductive reactance is less than the capacitive reactance.
349
MediumMHT CET2024
The magnetic energy in an inductor changes from maximum value to minimum value in 5 ms . When connected to an a.c. source, the frequency of the source is
Options:
A) 50 Hz
B) 200 Hz
C) 500 Hz
D) 20 Hz
350
MediumMHT CET2024
The core used in transformer and other electromagnetic devices is laminated to
Options:
A) increase the magnetic field.
B) increase the level of magnetic saturation of the core.
C) reduce the residual magnetism in the core.
D) reduce eddy current.
351
MediumMHT CET2024
In an a.c. circuit \mathrm{I}=100 \sin 200 \pi \mathrm{t}. The time required for the current to achieve its peak value will be
Options:
A) \frac{1}{100} \mathrm{~s}
B) \frac{1}{200} \mathrm{~s}
C) \frac{1}{300} \mathrm{~s}
D) \frac{1}{400} \mathrm{~s}
352
MediumMHT CET2024
In an A.C. circuit, the potential difference ' V ' and current 'I' are given respectively by \mathrm{V}=100 \sin (100 \mathrm{t}) \mathrm{V}, \mathrm{I}=100 \sin \left(100 \mathrm{t}+\frac{\pi}{3}\right) \mathrm{mA} The power dissipated in the circuit will be [Given \rightarrow \cos \frac{\pi}{3}=\frac{1}{2}]
Options:
A) 10^4 \mathrm{~W}
B) 10 W
C) 2.5 W
D) 5 W
353
MediumMHT CET2024
In the given circuit, when S_1 is closed, the capacitor gets fully charged. Now \mathrm{S}_1 is open and \mathrm{S}_2 is closed. Then
Options:
A) there is no exchange of energy between L and C .
B) the current in the circuit is in the same direction.
C) the instantaneous current in the circuit may be \mathrm{V}\left(\sqrt{\frac{\mathrm{C}}{\mathrm{L}}}\right).
D) the energy stored in the circuit is purely in the form of magnetic energy.
354
MediumMHT CET2023
The power factor of an R-L circuit is $\frac{1}{\sqrt{2}}. If the frequency of \mathrm{AC}$ is doubled the power factor will now be
Options:
A) \frac{1}{\sqrt{3}}
B) \frac{1}{\sqrt{5}}
C) \frac{1}{\sqrt{7}}
D) \frac{1}{\sqrt{11}}
355
MediumMHT CET2023
An alternating voltage $E=200 \sqrt{2} \sin (100 t) volt is connected to a 1 \mu \mathrm{f}$ capacitor through an a.c. ammeter. The reading of the ammeter shall
Options:
A) 10 mA
B) 20 mA
C) 40 mA
D) 80 ma
356
MediumMHT CET2023
What will be the phase difference between virtual voltage and virtual current when current in the circuit is wattless?
Options:
A) 60^{\circ}
B) 45^{\circ}
C) 90^{\circ}
D) 180^{\circ}
357
MediumMHT CET2023
A coil having an inductance of $\frac{1}{\pi} \mathrm{H} is connected in series with a resistance of 300 \Omega. If 20 \mathrm{~V} from a 200 \mathrm{~Hz}$ source are impressed across the combination, the value of the phase angle between the voltage and the current is
Options:
A) \tan ^{-1}\left(\frac{5}{4}\right)
B) \tan _{-1}\left(\frac{4}{5}\right)
C) \tan ^{-1}\left(\frac{3}{4}\right)
D) \tan ^{-1}\left(\frac{4}{3}\right)
358
MediumMHT CET2023
An alternating voltage is applied to a series LCR circuit. If the current leads the voltage by $45^{\circ}, then \left(\tan 45^{\circ}=1\right)
Options:
A) \mathrm{X}_{\mathrm{L}}=\mathrm{X}_{\mathrm{C}}-\mathrm{R}
B) \mathrm{X}_{\mathrm{L}}=\mathrm{X}_{\mathrm{C}}+\mathrm{R}
C) \mathrm{X}_{\mathrm{C}}=\sqrt{\mathrm{X}_{\mathrm{L}}^2+\mathrm{R}^2}
D) \mathrm{X}_{\mathrm{L}}=\sqrt{\mathrm{X}_{\mathrm{C}}^2+\mathrm{R}^2}
359
MediumMHT CET2023
For a purely inductive or a purely capacitive circuit, the power factor is
Options:
A) zero
B) 0.5
C) 1
D) \infty
360
MediumMHT CET2023
The reciprocal of the total effective resistance of LCR a.c. circuit is called
Options:
A) impedance
B) admittance
C) resistance
D) inductive and capacitive reactance
361
MediumMHT CET2023
The number of turns in the primary and the secondary of a transformer are 1000 and 3000 , respectively. If $80 \mathrm{~V} \mathrm{~AC}$ is applied to the primary coil of the transformer, then the potential difference per turn of the secondary coil would be
Options:
A) 240 V
B) 2400 V
C) 0.24 V
D) 0.08 V
362
MediumMHT CET2023
A group of lamps having total power rating of $1000 \mathrm{~W} is supplied by an AC voltage of E=200 \sin \left(310 t+60^{\circ}\right)$, the rms value of current flowing through the circuit is
Options:
A) 10 \mathrm{~A}
B) 5 \sqrt{2} \mathrm{~A}
C) 20 \mathrm{~A}
D) 10 \sqrt{2} \mathrm{~A}
363
MediumMHT CET2023
At a particular angular frequency, the reactance of capacitor and that of inductor is same. If the angular frequency is doubled, the ratio of the reactance of the capacitor to that of the inductor will be
Options:
A) 1/4
B) 1/2
C) 2
D) 4
364
MediumMHT CET2023
In a $L-R circuit the inductive reactance is equal to the resistance R in the circuit. An emf E=E_0 \cos \omega t$ is applied to the circuit. The power consumed in the circuit is
Options:
A) \frac{E_0^2}{\sqrt{2} R}
B) \frac{E_0^2}{4 R}
C) \frac{E_0^2}{2 R}
D) \frac{E_0^2}{8 R}
365
MediumMHT CET2023
In an oscillating LC circuit, the maximum charge on the capacitor is '$Q$'. When the energy is stored equally between the electric and magnetic fields, the charge on the capacitor becomes
Options:
A) \frac{\mathrm{Q}}{4}
B) \mathrm{\frac{Q}{2}}
C) \frac{\mathrm{Q}}{\sqrt{2}}
D) \frac{\mathrm{Q}}{\sqrt{3}}
366
MediumMHT CET2023
With increase in frequency of a.c. supply, the impedance of an L-C-R series circuit
Options:
A) remains constant.
B) increases.
C) decreases.
D) decreases at first, becomes minimum and then increases.
367
MediumMHT CET2023
In an a.c. circuit the instantaneous current and emf are represented as $\mathrm{I}=\mathrm{I}_0, \sin [\omega \mathrm{t}-\pi / 6] and \mathrm{E}=\mathrm{E}_0 \sin [\omega \mathrm{t}+\pi / 3]$ respectively. The voltage leads the current by
Options:
A) \frac{\pi}{2}
B) \frac{\pi}{4}
C) \frac{\pi}{3}
D) \frac{\pi}{6}
368
MediumMHT CET2023
When an inductor '$L' and a resistor 'R' in series are connected across a 15 \mathrm{~V}, 50 \mathrm{~Hz} a.c. supply, a current of 0.3 \mathrm{~A} flows in the circuit. The current differs in phase from applied voltage by \left(\frac{\pi}{3}\right)^c. The value of 'R' is \left(\sin \frac{\pi}{6}=\cos \frac{\pi}{3}=\frac{1}{2}, \sin \frac{\pi}{3}=\cos \frac{\pi}{6}=\frac{\sqrt{3}}{2}\right)
Options:
A) 10 \Omega
B) 15 \Omega
C) 20 \Omega
D) 25 \Omega
369
MediumMHT CET2023
An a.c. source of $15 \mathrm{~V}, 50 \mathrm{~Hz} is connected across an inductor (L) and resistance (R) in series R.M.S. current of 0.5 \mathrm{~A} flows in the circuit. The phase difference between applied voltage and current is \left(\frac{\pi}{3}\right) radian. The value of resistance (\mathrm{R}) is \left(\tan 60^{\circ}=\sqrt{3}\right)
Options:
A) 10 \Omega
B) 12 \Omega
C) 15 \Omega
D) 20 \Omega
370
MediumMHT CET2023
Resistor of $2\Omega, inductor of 100 \mu \mathrm{H} and capacitor of 400 \mathrm{pF} are connected in series across a source of \mathrm{e}_{\mathrm{rms}}=0.1$ Volt. At resonance, voltage drop across inductor is
Options:
A) 25 V
B) 2.5 V
C) 250 V
D) 20 V
371
MediumMHT CET2023
In the given circuit, r.m.s. value of current through the resistor $\mathrm{R}$ is
Options:
A) 2 \mathrm{~A}
B) 0.5 \mathrm{~A}
C) 20 \mathrm{~A}
D) 2 \sqrt{2} \mathrm{~A}
372
MediumMHT CET2023
In the given circuit, if $\frac{\mathrm{dI}}{\mathrm{dt}}=-1 \mathrm{~A} / \mathrm{s} then the value of \left(V_A-V_B\right)$ at this instance will be
Options:
A) 30 V
B) 24 V
C) 18 V
D) 9 V
373
MediumMHT CET2023
An inductor of $0.5 \mathrm{~mH}, a capacitor of 20 ~\mu \mathrm{F} and a resistance of 20 \Omega are connected in series with a 220 \mathrm{~V} a.c. source. If the current is in phase with the e.m.f. the maximum current in the circuit is \sqrt{x} A. The value of 'x$' is
Options:
A) 44
B) 82
C) 146
D) 242
374
MediumMHT CET2023
The a.c. source is connected to series LCR circuit. If voltage across $R is 40 \mathrm{~V}, that across \mathrm{L} is 80 \mathrm{~V} and that across \mathrm{C} is 40 \mathrm{~V}, then the e.m.f. 'e$' of a.c. source is
Options:
A) 40 V
B) 40$\sqrt2$ V
C) 80 V
D) 160 V
375
MediumMHT CET2023
In a series LCR circuit, $\mathrm{C}=2 \mu \mathrm{F}, \mathrm{L}=1 \mathrm{mH} and \mathrm{R}=10 \Omega$. The ratio of the energies stored in the inductor and the capacitor, when the maximum current flows in the circuit, is
Options:
A) 5: 1
B) 3: 2
C) 1: 2
D) 1: 5
376
MediumMHT CET2023
The a.c. source of e.m.f. with instantaneous value '$e' is given by e=200 \sin (50 t) volt. The r.m.s. value of current in a circuit of resistance 50 \Omega$ is
Options:
A) 0.2828 A
B) 2.828 A
C) 28.28 A
D) 282.8 A
377
MediumMHT CET2023
With the gradual increase in frequency of an a. c. source, the impedance of an LCR series circuit
Options:
A) first decreases, becomes minimum and then increases.
B) increases.
C) decreases.
D) remains constant.
378
MediumMHT CET2023
In series LCR circuit, the voltage across the inductance and the capacitance are not
Options:
A) out of phase with the voltage across the resistance by $90^{\circ}$.
B) equal in magnitude at resonance.
C) out of phase with each other by $180^{\circ}$.
D) in phase with the source voltage.
379
MediumMHT CET2023
With an alternating voltage source of frequency '$f', inductor 'L', capacitor 'C' and resistance 'R' are connected in series. The voltage leads the current by 45^{\circ}. The value of 'L' is \left(\tan 45^{\circ}=1\right)
Options:
A) \left(\frac{1+2 \pi \mathrm{fCR}}{4 \pi^2 \mathrm{f}^2 \mathrm{C}}\right)
B) \left(\frac{1-2 \pi \mathrm{fCR}}{4 \pi^2 \mathrm{f}^2 \mathrm{C}}\right)
C) \left(\frac{4 \pi^2 \mathrm{f}^2 \mathrm{C}}{1+2 \pi \mathrm{fCR}}\right)
D) \left(\frac{4 \pi^2 \mathrm{f}^2 \mathrm{C}}{1-2 \pi \mathrm{fCR}}\right)
380
MediumMHT CET2023
The capacitive reactance of a capacitor '$C' is \mathrm{X} \Omega$. Both, the frequency of a.c. supply and capacitance of the above capacitor are doubled. The new capacitive reactance will be
Options:
A) \frac{\mathrm{X}}{4} \Omega
B) \frac{\mathrm{X}}{2} \Omega
C) 2 \mathrm{X} \Omega
D) 4 \mathrm{X} \Omega
381
MediumMHT CET2023
A $100 \mathrm{~mH} coil carries a current of 1 \mathrm{~A}$. Energy stored in the form of magnetic field is
Options:
A) 0.025 J
B) 0.050 J
C) 0.075 J
D) 0.100 J
382
MediumMHT CET2023
In the circuit given below, the current through inductor is $0.9 \mathrm{~A} and through the capacitor is 0.6 \mathrm{~A}$. The current drawn from the a.c. source is
Options:
A) 1.5 A
B) 0.9 A
C) 0.6 A
D) 0.3 A
383
MediumMHT CET2023
The inductive reactance of a coil is '$\mathrm{X}_{\mathrm{L}}$'. If the inductance of a coil is tripled and frequency of a.c. supply is doubled, then the new inductive reactance will be
Options:
A) \frac{2}{3} X_L
B) \frac{3}{2} X_L
C) \frac{1}{6} X_L
D) 6 \mathrm{X}_{\mathrm{L}}
384
MediumMHT CET2023
In the circuit shown the ratio of quality factor and the bandwidth is
Options:
A) 10 s
B) 8 s
C) 6 s
D) 4 s
385
MediumMHT CET2023
In a series LR circuit, $X_L=R, power factor is P_1. If a capacitor of capacitance C with X_C=X_L is added to the circuit the power factor becomes P_2. The ratio of P_1 to P_2$ will be
Options:
A) 1: 3
B) 1: \sqrt{2}
C) 1: 1
D) 1: 2
386
MediumMHT CET2023
An e.m.f. $E=4 \cos (1000 t) volt is applied to an LR circuit of inductance 3 \mathrm{~mH} and resistance 4 ~\Omega$. The maximum current in the circuit is
Options:
A) \frac{4}{\sqrt{7}} \mathrm{~A}
B) 1.0 \mathrm{~A}
C) \frac{4}{7} \mathrm{~A}
D) 0.8 \mathrm{~A}
387
MediumMHT CET2023
An alternating voltage of frequency '$\omega' is induced in electric circuit consisting of an inductance 'L' and capacitance 'C$', connected in parallel. Then across the inductance coil
Options:
A) current is maximum when $\omega^2=\frac{1}{\mathrm{LC}}
B) current is zero
C) voltage is minimum when $\omega^2=\frac{1}{\text { LC }}
D) voltage is maximum when $\omega^2=\frac{1}{\mathrm{LC}}
388
MediumMHT CET2023
The reactance of capacitor at $50 \mathrm{~Hz} is 5 \Omega. If the frequency is increased to 100 \mathrm{~Hz}$, the new reactance is
Options:
A) 5 \Omega
B) 10 \Omega
C) 2.5 \Omega
D) 125 \Omega
389
MediumMHT CET2023
The coil of an a.c. generator has 100 turns, each of cross-sectional area $2 \mathrm{~m}^2. It is rotating at constant angular speed 30 ~\mathrm{rad} / \mathrm{s}, in a uniform magnetic field of 2 \times 10^{-2} \mathrm{~T}. If the total resistance of the circuit is 600 ~\Omega$ then maximum power dissipated in the circuit is
Options:
A) 6 \mathrm{~W}
B) 9 \mathrm{~W}
C) 12 \mathrm{~W}
D) 24 \mathrm{~W}
390
MediumMHT CET2023
A capacitor, an inductor and an electric bulb are connected in series to an a.c. supply of variable frequency. As the frequency of the supply is increased gradually, then the electric bulb is found to
Options:
A) increase in brightness.
B) decrease in brightness.
C) increase, reach a maximum and then decrease in brightness.
D) show no change in brightness.
391
MediumMHT CET2023
In an $\mathrm{AC} circuit, the current is \mathrm{i}=5 \sin \left(100 \mathrm{t}-\frac{\pi}{2}\right) \mathrm{A} and voltage is \mathrm{e}=200 \sin (100 \mathrm{t}) volt. Power consumption in the circuit is \left(\cos 90^{\circ}=0\right)
Options:
A) 200 \mathrm{~W}
B) 0 \mathrm{~W}
C) 40 \mathrm{~W}
D) 1000 \mathrm{~W}
392
MediumMHT CET2022
A capacitor of capacitance $50 \mu \mathrm{F} is connected to a.c. source \mathrm{e}=220 \sin 50 \mathrm{t} (\mathrm{e} in volt, \mathrm{t}$ in second). The value of peak current is
Options:
A) \frac{0.55}{\sqrt{2}} \mathrm{~A}
B) \frac{\sqrt{2}}{0.55} \mathrm{~A}
C) 0.55 \mathrm{~A}
D) \sqrt{2} \mathrm{~A}
393
MediumMHT CET2022
The resistance offered by an inductor $\left(X_L\right)$ in an a.c. circuit is
Options:
A) inversely proportional to inductance and frequency of the alternating current
B) inversely proportional to frequency of alternating current and directly proportional to inductance
C) inversely proportional to inductance and directly proportional to the frequency of alternating current
D) directly proportional to inductance and frequency of alternating current
394
MediumMHT CET2022
A coil having an inductance of $\frac{1}{\pi} \mathrm{H} is connected in series with a resistance of 300 \Omega. If A.C. Source (20 \mathrm{~V}-200 \mathrm{~Hz})$ is connected across the combination, the phase angle between voltage and current is
Options:
A) \tan ^{-1}\left(\frac{3}{4}\right)
B) \tan ^{-1}\left(\frac{4}{3}\right)
C) \tan ^{-1}\left(\frac{5}{4}\right)
D) \tan ^{-1}\left(\frac{4}{5}\right)
395
MediumMHT CET2022
In a full wave rectifier circuit without filter, the output current is
Options:
A) an eddy current
B) a constant direct current
C) a sinusoidal current
D) unidirectional but not steady current
396
MediumMHT CET2021
A rejector circuit is the resonant circuit in which
Options:
A) \mathrm{L}-\mathrm{C}-\mathrm{R}$ are connected in parallel.
B) \mathrm{L}-\mathrm{C}-\mathrm{R}$ are connected in series.
C) \mathrm{C}-\mathrm{R}$ are connected in series.
D) L-R are connected in series.
397
MediumMHT CET2021
In series LCR circuit, at resonance the peak value of current will be [$\mathrm{E_0} is peak emf, R is resistance, \omega \mathrm{L} is inductive reactance and \omega \mathrm{C}$ is capacitive]
Options:
A) \frac{E_0}{R}
B) \frac{E_0}{\sqrt{2} R}
C) \frac{E_0}{\sqrt{R^2+\left(\omega L-\frac{1}{\omega C}\right)^2}}
D) \frac{E_0}{\sqrt{2} \sqrt{R^2+\left(\omega L-\frac{1}{\omega C}\right)^2}}
398
MediumMHT CET2021
An alternating e.m.f. is $\mathrm{e}=\mathrm{e}_0 \sin \omega \mathrm{t}. In what time the e.m.f. will have half its maximum value, if '\mathrm{e}' starts from zero? (\mathrm{T}= time period, \sin 30^{\circ}=0.5$)
Options:
A) \frac{\mathrm{T}}{12}
B) \mathrm{\frac{T}{16}}
C) \frac{\mathrm{T}}{4}
D) \mathrm{\frac{T}{8}}
399
MediumMHT CET2021
A step up transformer operates on $220 \mathrm{~V} and supplies current of 2 \mathrm{~A}. The ratio of primary and secondary windings is 1: 20$. The current in the primary is
Options:
A) 5 A
B) 2 A
C) 40 A
D) 20 A
400
MediumMHT CET2021
In the part of an a.c. circuit as shown, the resistance $R=0.2 \Omega. At a certain instant (\mathrm{V_A-V_B})= 0.5 \mathrm{~V}, \mathrm{I}=0.5 \mathrm{~A} and \frac{\Delta \mathrm{I}}{\Delta \mathrm{t}}=8 \mathrm{~A} / \mathrm{s}$. The inductance of the coil is
Options:
A) 0.04 H
B) 0.02 H
C) 0.08 H
D) 0.05 H
401
MediumMHT CET2021
In the circuit shown in the figure, a.c. source gives voltage $\mathrm{V}=20 \cos (2000 \mathrm{t})$. Impedance and r.m.s. current respectively will be
Options:
A) 10 \Omega, 0.5 \mathrm{~A}
B) 5 \Omega, 2 \mathrm{~A}
C) 10 \Omega, \sqrt{2} \mathrm{~A}
D) 5 \Omega, 1 \mathrm{~A}
402
MediumMHT CET2021
Which graph shows the correct variation of r.m.s. current 'I' with frequency 'f' of a.c. in case of (LCR) parallel resonance circuit?
Options:
A) Q
B) P
C) R
D) S
403
MediumMHT CET2021
The peak value of an alternating emf '$\mathrm{e}' given by \mathrm{e}=\mathrm{e}_0 \cos \omega \mathrm{t} is 10 volt and its frequency is 50 \mathrm{~Hz}. At time \mathrm{t}=\frac{1}{600} \mathrm{~s}, the instantaneous e.m.f is \left(\cos \frac{\pi}{6}=\sin \frac{\pi}{3}=\frac{\sqrt{3}}{2}\right)
Options:
A) 10 \mathrm{~V}
B) \frac{1}{\sqrt{3}} \mathrm{~V}
C) 5 \mathrm{~V}
D) 5 \sqrt{3} \mathrm{~V}
404
MediumMHT CET2021
A circuit containing resistance R$_1, inductance L_1 and capacitance C_1 connected in series resonates at the same frequency 'f_0' as another circuit containing R_2, L_2 and C_2$ in series. If two circuits are connected in series then the new frequency at resonance is
Options:
A) \mathrm{\frac{3}{4} f_r}
B) \frac{3}{2} \mathrm{f}_{\mathrm{r}}
C) \mathrm{2 f_r}
D) \mathrm{f}_{\mathrm{r}}
405
MediumMHT CET2021
A series L-C-R circuit containing a resistance of $120 ~\Omega has angular frequency 4 \times 10^5 \mathrm{~rad} \mathrm{~s}^{-1}. At resonance the voltage across resistance and inductor are 60 \mathrm{~V} and 40 \mathrm{~V}$ respectively, then the value of inductance will be
Options:
A) 0.2 \mathrm{~mH}
B) 0.4 \mathrm{~mH}
C) 0.8 \mathrm{~mH}
D) 0.6 \mathrm{~mH}
406
MediumMHT CET2021
For series LCR circuit, which one of the following is a CORRECT statement?
Options:
A) Potential difference across resistance $\mathrm{R} and that across capacitor have phase difference \frac{\pi^{\mathrm{c}}}{2}$.
B) Applied e.m.f. and potential difference across resistance '$R$' are in the same phase
C) Applied e.m.f. and potential difference inductor coil has phase difference of $\frac{\pi^{\mathrm{c}}}{2}
D) Potential difference across capacitor and that across inductor have phase difference of $\frac{\pi^{\mathrm{c}}}{2}$.
407
MediumMHT CET2021
In an LCR series a.c. circuit, the voltage across each of the components L, C and R is 60 V. The voltage across the LC combination is
Options:
A) 120 V
B) 60 V
C) zero V
D) \frac{60}{\sqrt{3}}$ V
408
MediumMHT CET2021
If we increase the frequency of an a.c. supply, then inductive reactance
Options:
A) increases directly with the square of frequency
B) increases as it directly proportional to frequency
C) decreases inversely with the square of frequency
D) decreases as it is inversely proportional to the frequency
409
MediumMHT CET2021
A capacitor of capacity '$C' is charged to a potential 'V'. It is connected in parallel to an inductor of inductance '\mathrm{L}$'. The maximum current that will flow in the circuit is
Options:
A) V \sqrt{\frac{L}{C}}
B) \mathrm{V} \sqrt{\mathrm{LC}}
C) V \sqrt{\frac{C}{L}}
D) \frac{\mathrm{VC}^2}{\mathrm{~L}}
410
MediumMHT CET2021
A step down transformer is used to reduce the main supply from '$V_1' volt to 'V_2' volt. The primary coil draws a current '\mathrm{I}_1' \mathrm{A} and the secondary coil draws '\mathrm{I}_2' A. (\mathrm{I}_1<\mathrm{I}_2)$. The ratio of input power to output power is
Options:
A) \frac{V_1 V_2}{I_1 I_2}
B) \frac{V_1 I_1}{V_2 I_2}
C) \frac{\mathrm{I}_1 \mathrm{I}_2}{\mathrm{~V}_1 \mathrm{~V}_2}
D) \frac{\mathrm{V}_1 \mathrm{I}_2}{\mathrm{~V}_2 \mathrm{I}_1}
411
MediumMHT CET2021
For the circuit shown below, instantaneous current through inductor '$\mathrm{L}' and capacitor '\mathrm{C}$' is respectively.
Options:
A) \frac{-\mathrm{e}_0}{\omega \mathrm{L}} \cos \omega \mathrm{t} ; \mathrm{e}_0 \omega \mathrm{c} \cos \omega \mathrm{t}
B) \frac{-\mathrm{e}_0}{\omega \mathrm{L}} \sin \omega t ; \frac{\mathrm{e}_0}{\omega \mathrm{C}} \cos \omega \mathrm{t}
C) \frac{\mathrm{e}_0 \mathrm{C}}{\mathrm{L}} \cos \omega \mathrm{t}; \frac{\mathrm{e}_0 \mathrm{~L}}{\mathrm{C}} \sin \omega \mathrm{t}
D) \frac{-\mathrm{e}_0 \mathrm{C}}{\mathrm{L}} \sin \omega \mathrm{t} ; \frac{\mathrm{e}_0 \mathrm{~L}}{\mathrm{C}} \cos \omega \mathrm{t}
412
MediumMHT CET2021
A parallel plate capacitor having plates of radius 6 cm has capacitance 100 pF. It is connected to 230 V a.c. supply with angular frequency 300 rad/s. The r.m.s. value of current is
Options:
A) 6.9\times10^{-6}$ A
B) 2.3\times10^{-5}$ A
C) 6.9\times10^{-5}$ A
D) 6.9\times10^{-7}$ A
413
MediumMHT CET2021
A step down transformer has turns ratio $20: 1. If 8 \mathrm{~V} is applied across 0.4 \mathrm{~ohm}$ secondary then the primary current will be
Options:
A) 2 A
B) 1 A
C) 0.5 A
D) 4 A
414
MediumMHT CET2021
An a.c. source of angular frequency '$\omega' is fed across a resistor 'R' and a capacitor 'C' in series. The current registered is I. If now the frequency of source is changed to \frac{\omega}{3} (but maintaining the same voltage), the current in the circuit is found to be halved. The ratio of reactance to resistance at the original frequency '\omega$' will be
Options:
A) \sqrt{\frac{2}{5}}
B) \sqrt{\frac{1}{5}}
C) \sqrt{\frac{4}{5}}
D) \sqrt{\frac{3}{5}}
415
MediumMHT CET2021
In an a.c. circuit, a resistance R = 40 $\Omega and an inductance 'L' are connected in series. If the phase angle between voltage and current is 45^\circ, then the value of the inductive reactance is (tan 45^\circ$ = 1)
Options:
A) 50$\Omega
B) 40$\Omega
C) 10$\Omega
D) 20$\Omega
416
MediumMHT CET2021
The frequency of the output signal of an LC oscillator circuit is '$\mathrm{F}' Hz with a capacitance of 0.1 \mu \mathrm{F}. If the value of the capacitor is increased to 0.2~ \mu \mathrm{F}$, then the frequency of the output signal will be
Options:
A) \frac{\mathrm{F}}{\sqrt{2}} \mathrm{~Hz}
B) \frac{\mathrm{F}}{\sqrt{3}} \mathrm{~Hz}
C) \frac{\mathrm{F}}{2} \mathrm{~Hz}
D) 2 \mathrm{~F} \mathrm{~Hz}
417
MediumMHT CET2021
In LCR series resonant circuit, at resonance, voltage across 'L' and 'C' will cancel each other because they are
Options:
A) 90$^\circ$ out of phase
B) 90$^\circ$ in phase
C) 180$^\circ$ in phase
D) 180$^\circ$ out of phase
418
MediumMHT CET2021
The inductive reactance of a coil is R$\Omega$. If the inductance of a coil is doubled and frequency of a.c. supply is also doubled then the new inductive reactance will be
Options:
A) 2R
B) 8R
C) \mathrm{\frac{R}{2}}
D) 4R
419
MediumMHT CET2021
Three pure inductors each of inductance 6H are connected as shown in the figure. Their equivalent inductance between the points 'P' and 'Q' is
Options:
A) 0.5 H
B) 18 H
C) 6.3 H
D) 2 H
420
MediumMHT CET2021
The instantaneous value of an alternating current is given by $\mathrm{i}=50 \sin (100 \pi \mathrm{t}). It will achieve a value of 25 \mathrm{~A} after a time interval of \left(\sin 30^{\circ}=0.5\right)
Options:
A) \frac{1}{300} \mathrm{~S}
B) \frac{1}{100} \mathrm{~S}
C) \frac{1}{200} \mathrm{~S}
D) \frac{1}{600} \mathrm{~S}
421
MediumMHT CET2021
In a step up transformer, which one of the following statements is correct?
Options:
A) Number of turns in the secondary coil is less than in primary coil.
B) Voltage in secondary coil is less than voltage is primary coil.
C) Current in the primary coil is more than current in the secondary coil.
D) Current in the primary coil is equal to current in the secondary coil.
422
MediumMHT CET2021
In the graphical representation of e.m.f. '$\mathrm{e}' and current '\mathrm{i}' versus '\omega \mathrm{t}$' for an a.c. circuit, both emf and current reach zero, minimum and maximum value at the same time. The circuit element connected to the source will be
Options:
A) pure capacitor
B) combination of capacitor and inductor
C) pure resistor
D) pure inductor
423
MediumMHT CET2021
An alternating voltge is represented by $\mathrm{V}=80 \sin (100 \pi \mathrm{t}) \cos (100 \pi \mathrm{t})$ volt. The peak voltage is
Options:
A) 20 \mathrm{~V}
B) 40 \mathrm{~V}
C) 30 \mathrm{~V}
D) 50 \mathrm{~V}
424
MediumMHT CET2021
A series combination of resistor 'R' and capacitor 'C' is connected to an a.c. source of angular frequency '$\omega'. Keeping the voltage same, if the frequency is changed to \frac{\omega}{3}$ the current becomes half of the original current. Then the ratio of capacitive reactance and resistance at the former frequency is
Options:
A) \sqrt{0.6}
B) \sqrt{6}
C) \sqrt{3}
D) \sqrt{2}
425
MediumMHT CET2021
An inductive coil has a resistance of $100 ~\Omega. When an a.c. signal of frequency 1000 \mathrm{~Hz} is applied to the coil the voltage leads the current by 45^{\circ}. The inductance of the coil is \left(\tan 45^{\circ}=1\right.$)
Options:
A) \frac{0.25}{2 \pi} \mathrm{H}
B) \frac{0.05}{\pi} \mathrm{H}
C) \frac{0.25}{\pi} \mathrm{H}
D) \frac{0.5}{\pi} \mathrm{H}
426
MediumMHT CET2021
In an ideal step down transformer, out of the following quantities, which quantity increases in the secondary coil?
Options:
A) Power
B) Voltage
C) Current
D) Frequency
427
MediumMHT CET2021
A series LCR circuit with resistance (R) $500 ~\mathrm{ohm} is connected to an a.c. source of 250 \mathrm{~V}. When only the capacitance is removed, the current lags behind the voltage by 60^{\circ}. When only the inductance is removed, the current leads the voltage by 60^{\circ}. The impedance of the circuit is \left(\tan \frac{\pi}{3}=\sqrt{3}\right)
Options:
A) \frac{500}{\sqrt{3}} \Omega
B) 500 \sqrt{3} \Omega
C) 250 \Omega
D) 500 \Omega
428
MediumMHT CET2021
When a d.c. voltage of $200 \mathrm{~V} is applied to a coil of self-inductance \left(\frac{2 \sqrt{3}}{\pi}\right) \mathrm{H}, a current of 1 \mathrm{~A} flows through it. But by replacing d.c. source with a.c. source of 200 \mathrm{~V}, the current in the coil is reduced to 0.5 \mathrm{~A}$. Then the frequency of a.c. supply is
Options:
A) 100 Hz
B) 60 Hz
C) 75 Hz
D) 50 Hz
429
MediumMHT CET2021
An inductor coil wound uniformly has self inductance 'L' and resistance 'R'. The coil is broken into two identical parts. The two parts are then connected in parallel across a battery of 'E' volt of negligible internal resistance. The current through battery at steady state is
Options:
A) \mathrm{\frac{2E}{R}}
B) \mathrm{\frac{3E}{R}}
C) \mathrm{\frac{4E}{R}}
D) \mathrm{\frac{E}{R}}
430
MediumMHT CET2021
An inductor coil takes current 8A when connected to an 100 V and 50 Hz a.c. source. A pure resistor under the same condition takes current of 10A. If inductor coil and resistor are connected in series to an 100V and 40 Hz a.c. supply, then the current in the series combination of above resistor and inductor is
Options:
A) \frac{10}{\sqrt3}$A
B) \frac{5}{\sqrt2}$A
C) 10$\sqrt2$A
D) 5$\sqrt2$A
431
MediumMHT CET2020
An AC circuit contains resistance of 12 \Omega and inductive reactance 5 \Omega. The phase angle between current and potential difference will be
Options:
A) \sin ^{-1}\left(\frac{12}{13}\right)
B) \cos ^{-1}\left(\frac{5}{12}\right)
C) \sin ^{-1}\left(\frac{5}{12}\right)
D) \cos ^{-1}\left(\frac{12}{13}\right)
432
MediumMHT CET2020
A step-up transformer has 300 turns of primary winding and 450 turns of secondary winding. A primary is connected to 150 V and the current flowing through it is 9A. The current and voltage in the secondary are
Options:
A) 13.5 \mathrm{~A}, 100 \mathrm{~V}
B) 13.5 \mathrm{~A}, 225 \mathrm{~V}
C) 4.5 \mathrm{~A}, 100 \mathrm{~V}
D) 6.0 \mathrm{~A}, 225 \mathrm{~V}
433
MediumMHT CET2020
An alternating emf of $0.2 \mathrm{~V} is applied across an L-C-R series circuit having R=4 \Omega, C=80 \mu \mathrm{F} and L=200 \mathrm{~mH}$. At resonance the voltage drop across the inductor is
Options:
A) 10V
B) 2.5V
C) 1V
D) 5V
434
MediumMHT CET2019
A 220 V input is supplied to a transformer. The output circuit draws a current of 2.0 A at 440 V . If the ratio of output to input power is 0.8 , then the current drawn by primary winding is
Options:
A) 3.6 A
B) 5.0 A
C) 2.5 A
D) 2.8 A
435
MediumMHT CET2019
A coil has inductance 2 H . The ratio of its reactance, when it is connected first to an A C source and then to DC source, is
Options:
A) zero
B) 1
C) less than 1
D) infinity
436
MediumMHT CET2019
An alternating voltage is given by E=100 \sin \left(\omega+\frac{\pi}{6}\right) \mathrm{V}. The voltage will be maximum for the first time when is [ T= periodic time)
Options:
A) \frac{T}{12}
B) \frac{T}{2}
C) \frac{T}{6}
D) \frac{T}{3}
437
MediumMHT CET2019
In a series L C R circuit R=300 \Omega, L=0.9 \mathrm{H}, C=2 \mu \mathrm{~F}, \omega=1000 \mathrm{rad} / \mathrm{s}. The impedance of the circuit is
Options:
A) 500 \Omega
B) 1300 \Omega
C) 400 \Omega
D) 900 \Omega
438
EasyNEET2025
To an ac power supply of 220 V at 50 Hz , a resistor of 20 \Omega, a capacitor of reactance 25 \Omega and an inductor of reactance 45 \Omega are connected in series. The corresponding current in the circuit and the phase angle between the current and the voltage is, respectively
Options:
A) 15.6 A and 30^{\circ}
B) 15.6 A and 45^{\circ}
C) 7.8 A and 30^{\circ}
D) 7.8 A and 45^{\circ}
439
MediumNEET2024
In the circuit shown below, the inductance $L is connected to an ac source. The current flowing in the circuit is I=I_0 \sin \omega t. The voltage drop \left(V_L\right) across L$ is
Options:
A) \omega L I_0 \sin \omega t
B) \frac{I_0}{\omega L} \sin \omega t
C) \frac{I_0}{\omega L} \cos \omega t
D) \omega L I_0 \cos \omega t
440
MediumNEET2024
A step up transformer is connected to an ac mains supply of $220 \mathrm{~V} to operate at 11000 \mathrm{~V}, 88$ watt. The current in the secondary circuit, ignoring the power loss in the transformer, is
Options:
A) 8 mA
B) 4 mA
C) 0.4 A
D) 4 A
441
MediumNEET2024
The amplitude of the charge oscillating in a circuit decreases exponentially as $Q=Q_0 e^{-R t/2 L}, where Q_0 is the charge at t=0 \mathrm{~s}. The time at which charge amplitude decreases to 0.50 Q_0 is nearly: [Given that R=1.5 \Omega, L=12 \mathrm{~mH}, \ln (2)=0.693$]
Options:
A) 19.01 ms
B) 11.09 ms
C) 19.01 s
D) 11.09 s
442
MediumNEET2024
In an ideal transformer, the turns ratio is $\frac{N_P}{N_S}=\frac{1}{2}. The ratio V_S: V_P$ is equal to (the symbols carry their usual meaning) :
Options:
A) 1: 2
B) 2: 1
C) 1: 1
D) 1: 4
443
MediumNEET2024
A $10 \mu \mathrm{F} capacitor is connected to a 210 \mathrm{~V}, 50 \mathrm{~Hz} source as shown in figure. The peak current in the circuit is nearly (\pi=3.14)$ :
Options:
A) 0.58 A
B) 0.93 A
C) 1.20 A
D) 0.35 A
444
MediumNEET2023
An ac source is connected in the given circuit. The value of \phi will be :
Options:
A) 60^{\circ}
B) 90^{\circ}
C) 30^{\circ}
D) 45^{\circ}
445
MediumNEET2023
If Z$_1 and Z_2$ are the impedances of the given circuits (a) and (b) as shown in figures, then choose the correct option
Options:
A) Z$_1 < Z_2
B) Z$_1 + Z_2 = 20 \Omega
C) Z$_1 = Z_2
D) Z$_1 > Z_2
446
MediumNEET2023
The maximum power is dissipated for an ac in a/an:
Options:
A) resistive circuit
B) LC circuit
C) inductive circuit
D) capacitive circuit
447
MediumNEET2023
For very high frequencies, the effective impedance of the circuit (shown in the figure) will be:-
Options:
A) 4 $\Omega
B) 6 $\Omega
C) 1 $\Omega
D) 3 $\Omega
448
MediumNEET2023
In a series LCR circuit, the inductance $L is 10 ~\mathrm{mH}, capacitance C is 1 ~\mu \mathrm{F} and resistance R is 100 ~\Omega$. The frequency at which resonance occurs is :-
Options:
A) 15.9 kHz
B) 1.59 rad/s
C) 1.59 kHz
D) 15.9 rad/s
449
MediumNEET2023
A $12 \mathrm{~V}, 60 \mathrm{~W} lamp is connected to the secondary of a step down transformer, whose primary is connected to ac mains of 220 \mathrm{~V}$. Assuming the transformer to be ideal, what is the current in the primary winding ?
Options:
A) 2.7 A
B) 3.7 A
C) 0.37 A
D) 0.27 A
450
MediumNEET2023
An ac source is connected to a capacitor C. Due to decrease in its operating frequency
Options:
A) displacement current increases.
B) displacement current decreases.
C) capacitive reactance remains constant.
D) capacitive reactance decreases.
451
MediumNEET2023
The magnetic energy stored in an inductor of inductance $4 ~\mu \mathrm{H} carrying a current of 2 \mathrm{~A}$ is :
Options:
A) 4 \mathrm{~mJ}
B) 8 \mathrm{~mJ}
C) 8 ~\mu \mathrm{J}
D) 4 ~\mu \mathrm{J}
452
MediumNEET2023
The net impedance of circuit (as shown in figure) will be :
Options:
A) 15 \Omega
B) 5 \sqrt{5} \Omega
C) 25 \Omega
D) 10 \sqrt{2} \Omega
453
MediumNEET2022
Given below are two statements Statement I : In an a.c circuit, the current through a capacitor leads the voltage across it. Statement II : In a.c circuit containing pure capacitance only, the phase difference between the current and voltage is $\pi$. In the light of the above statements, choose the most appropriate answer from the options given below
Options:
A) Statement I is incorrect but Statement II is correct
B) Both Statement I and Statement II are correct
C) Both Statement I and Statement II are incorrect
D) Statement I is correct but Statement II is incorrect
454
MediumNEET2022
An inductor of inductance 2 mH is connected to a 220 V, 50 Hz ac source. Let the inductive reactance in the circuit is X1. If a 220 V dc source replace the ac source in the circuit, then the inductive reactance in the circuit is X2. X1 and X2 respectively are :
Options:
A) 0.628 $\Omega$, infinity
B) 6.28 $\Omega$, zero
C) 6.28 $\Omega$, infinity
D) 0.628 $\Omega$, zero
455
MediumNEET2022
A standard filament lamp consumes 100 W when connected to 200 V ac mains supply. The peak current through the bulb will be :
Options:
A) 2 A
B) 0.707 A
C) 1 A
D) 1.414 A
456
MediumNEET2022
The peak voltage of the ac source is equal to
Options:
A) The value of voltage supplied to the circuit
B) The rms value of the ac source
C) \sqrt2$ times the rms value of the ac source
D) 1/$\sqrt2$ times the rms value of the ac source
457
MediumNEET2022
A series LCR circuit with inductance 10 H, capacitance 10 $\muF, resistance 50 \Omega$ is connected to an ac source of voltage, V = 200sin(100t) volt. If the resonant frequency of the LCR circuit is v0 and the frequency of the ac source is v, then
Options:
A) {v_0} = v = 50$ Hz
B) {v_0} = v = {{50} \over \pi }$ Hz
C) {v_0} = {{50} \over \pi } Hz, v = 50$ Hz
D) v = 100 Hz, {v_0} = {{100} \over \pi }$ Hz
458
MediumNEET2021
An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance 'R' are connected in series to an ac source of potential difference 'V' volts as shown in figure. Potential difference across L, C and R is 40V, 10V and 40V, respectively. The amplitude of current flowing through LCR series circuit is 10$\sqrt 2 $ A. The impedance of the circuit is :
Options:
A) 5$\Omega
B) 4$\sqrt 2 \Omega
C) 5/$\sqrt 2 \Omega
D) 4$\Omega
459
MediumNEET2021
A capacitor of capacitance 'C', is connected across an ac source of voltage V, given by V = V0sin$\omega$tThe displacement current between the plates of the capacitor, would then be given by :
Options:
A) {I_d} = {V_0}\omega C\sin \omega t
B) {I_d} = {V_0}\omega C\cos \omega t
C) {I_d} = {{{V_0}} \over {\omega C}}\cos \omega t
D) {I_d} = {{{V_0}} \over {\omega C}}\sin \omega t
460
MediumNEET2021
A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit ?
Options:
A) 4A
B) 0.2A
C) 0.4A
D) 2A
461
MediumNEET2021
A series LCR circuit containing 5.0 H inductor, 80$\muF capacitor and 40\Omega$ resistor is connected to 230V variable frequency ac source. The angular frequencies of the source at which power transferred to the circuit is half the power at the resonant angular frequency are likely to be :
Options:
A) 42 rad/s and 58 rad/s
B) 25 rad/s and 75 rad/s
C) 50 rad/s and 25 rad/s
D) 46 rad/s and 54 rad/s
462
MediumNEET2020
A 40 $\mu $F capacitor is connected to a 200 V. 50 Hz ac supply. The rms value of the current on the circuit is, nearly :
Options:
A) 2.05 A
B) 2.5 A
C) 25.1 A
D) 1.7 A
463
MediumNEET2020
A series LCR circuit is connected to an ac voltage source. When L is removed from the circuit, the phase difference between current and voltage is ${\pi \over 3}. If instead C is removed from the circuit, the phase difference is again {\pi \over 3}$ between current and voltage. The power factor of the circuit is :
Options:
A) 0.5
B) 1.0
C) - $
1.0
D) zero
464
MediumNEET2018
The magnetic potential energy stored in a certain inductor is 25 mJ, when the current in the inductor is 60 mA. This inductor is of inductance
Options:
A) 0.138 H
B) 138.88 H
C) 1.389 H
D) 13.89 H
465
MediumNEET2018
An inductor 20 mH, a capacitor 100 $\mu F and a resistor 50 \Omega $ are connected in series across a source of emf, V = 10 sin 314 t. The power loss in the circuit is
Options:
A) 0.79 W
B) 0.43 W
C) 2.74 W
D) 1.13 W
466
MediumNEET2017
Figure shows a circuit that contains three identical resistors with resistance R = 9.0 $\Omega each, two identical inductors with inductance L = 2.0 mH each, and an ideal battery with emf \varepsilon = 18V. The current i$ through the battery just after the switch closed is
Options:
A) 0.2 A
B) 4 A
C) 0 ampere
D) 2 mA
467
MediumNEET2016
Which of the following combinations should be selected for better tuning of an L-C-R circuit used for combination ?
Options:
A) R = 20 $\Omega , L = 1.5 H, C = 35 \mu $F
B) R = 25 $\Omega , L = 2.5 H, C = 45 \mu $F
C) R = 15 $\Omega , L = 3.5 H, C = 30 \mu $F
D) R = 25 $\Omega , L = 1.5 H, C = 45 \mu $F
468
MediumNEET2016
The potential differences across the resistance, capacitance and inductance are 80 V, 40 V and 100 V respectively in an L-C-R circuit. The power factor of this circuit is
Options:
A) 0.4
B) 0.5
C) 0.8
D) 1.0
469
MediumNEET2016
A 100 $\Omega resistance and a capacitor of 100 \Omega $ reactance are connected in series across a 220 V source. When the capacitor is 50% charged, the peak value of the displacement current is
Options:
A) 2.2 A
B) 11 A
C) 4.4 A
D) 11$\sqrt 2 A
470
MediumNEET2016
A small signal voltage V(t) = V0 sin$\omega $t is applied across an ideal capacitor C
Options:
A) Current $I(t) is in phase with voltage V(t)$.
B) Current $I(t)$ leads voltage V(t) by 180o
C) Current $I(t), legs voltage V(t)$ by 90o.
D) Over a full cycle the capacitor C foes not consume any energy from the voltage source.
471
MediumNEET2016
An inductor 20 mH, a capacitor 50 $\mu F and a resistor 40 \Omega $ are connected in series across a source of emf V = 10 sin 340t. The power loss in A.C. circuit is
Options:
A) 0.76 W
B) 0.89 W
C) 0.51 W
D) 0.67 W
472
MediumNEET2015
A series R-C circuit is connected to an alternating voltage source. Consider two situations : (a) When capacitor is air filled. (b) When capacitor is mica filled. Current through resistor is $I and voltage across capacitor is V$ then
Options:
A) {i_a} > {i_b}
B) {V_a} = {V_b}
C) {V_a} < {V_b}
D) {V_a} > {V_b}
473
MediumNEET2015
A resistance 'R' draws power 'P' when connected to an AC source. If an inductance is now placed in series with the resistance, such that the impedance of the circuit becomes 'Z'. the power drawn will be
Options:
A) P\left( {{R \over Z}} \right)
B) P
C) P{\left( {{R \over Z}} \right)^2}
D) P\sqrt {{R \over Z}}
474
MediumNEET2014
A transformer having efficiency of 90% is working on 200 V and 3 kW power supply. If the current in the secondary coil is 6 A, the voltage across the secondary coil and the current in the primary coil respectively are
Options:
A) 300 V, 15 A
B) 450 V, 15 A
C) 450 V, 13.5 A
D) 600 V, 15 A
475
MediumNEET2013
The primary of a transformer when connected to a dc battery of 10 Volt draws a current of 1 mA. The number of turns of the primary and secondary windings are 50 and 100 respectively. The voltage in the secondary and the current drawn by the circuit in the secondary are respectively
Options:
A) 20 V and 2.0 mA
B) 10 V and 0.5 mA
C) Zero volt and therefore no current
D) 20 V and 0.5 mA
476
MediumNEET2013
A coil of self-inductance L is connected in series with a bulb B and an AC source. Brightness of the bulb decreases when
Options:
A) a capacitance of reactance XC = XL is included in the same citcuit.
B) an iron rod is inserted in the coil.
C) frequency of the AC source is decreased.
D) number of turns in the coil is reduced.
477
MediumNEET2012
The instantaneous values of alternating current and voltage in a circuit are given as $i = {1 \over {\sqrt 2 }} sin (100 \pi t) ampere e = {1 \over {\sqrt 2 }}\sin \left( {100\pi t + {\pi \over 3}} \right)$ Volt The average power in watts consumed in the circuit is
Options:
A) {1 \over 4}
B) {{\sqrt 3 } \over 4}
C) {1 \over 2}
D) {1 \over 8}
478
MediumNEET2012
The current $(I)$ in the inductance is varying with time according to the plot shown in figure. Which one of the following is the correct variation of voltage with time in the coil ?
Options:
A)
B)
C)
D)
479
MediumNEET2012
In an electrical circuit R, L, C and a.c. voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and the current in the circuit is If instead, C is removed from the circuit, the phase difference is again. The power factor of the circuit is
Options:
A) {1 \over 2}
B) {1 \over {\sqrt 2 }}
C) 1
D) {{\sqrt 3 } \over 2}
480
MediumNEET2011
A coil has resistance 30 ohm and inductive reactance 20 ohm at 50 Hz frequency. If an ac source, of 200 volt, 100 Hz, is connected across the coil, the current in the coil will be
Options:
A) 2.0 A
B) 4.0 A
C) 8.0 A
D) {{20} \over {\sqrt {13} }}A
481
MediumNEET2011
The r.m.s. value of potential difference V shown in the figure is
Options:
A) {{{V_0}} \over {\sqrt 3 }}
B) V0
C) {{{V_0}} \over {\sqrt 2 }}
D) {{{V_0}} \over 2}
482
MediumNEET2011
An ac voltage is applied to a resistance R and an inductor L in series. If R and the inductive reactance are both equal to 3 $\Omega $, the phase difference between the applied voltage and the current in the circuit is
Options:
A) \pi /6
B) \pi /4
C) \pi /2
D) zero
483
MediumNEET2011
In the ac circuit an alternating voltage e = $200\sqrt 2 sin100t volts is connected to a capacitor of capacity 1 \mu $F. The r.m.s. value of the current in the circuit is
Options:
A) 10 mA
B) 100 mA
C) 200 mA
D) 20 mA
484
MediumNEET2010
A condenser of capacity C is charged to a potential difference of V1. The plates of th condenser are then connected to an ideal inductor of inductance L. The current through the inductor when the potential difference across the condenser reduces to V2 is
Options:
A) {\left( {{{C{{\left( {{V_1} - {V_2}} \right)}^2}} \over L}} \right)^{{1 \over 2}}}
B) {{C\left( {V_1^2 - V_2^2} \right)} \over L}
C) {{C\left( {V_1^2 + V_2^2} \right)} \over L}
D) {\left( {{{C\left( {V_1^2 - V_2^2} \right)} \over L}} \right)^{{1 \over 2}}}
485
MediumNEET2010
A 220 volt input is supplied to a transformer. The output circuit draws a current of 2.0 ampere at 440 volts. If the efficiency of the transformer is 80%, the current drwn by the primary windings of the transformer is
Options:
A) 3.6 ampere
B) 2.8 ampere
C) 2.5 ampere
D) 5.0 ampere
486
MediumNEET2010
In the given circuit the reading of voltmeter V1 and V2 are 300 volts each. The reading of the voltmeter V3 and ammeter A are respectively
Options:
A) 150V, 2.2A
B) 220V, 2.2A
C) 220V, 2.0A
D) 100V, 2.0A
487
MediumNEET2009
Power dissipated in an LCR series circuit connected to an A.C. source of emf $\varepsilon $ is
Options:
A) {{{\varepsilon ^2}\sqrt {{R^2} + {{\left( {L\omega - {1 \over {\omega }}} \right)}^2}} } \over R}
B) {{{\varepsilon ^2}\sqrt {{R^2} + {{\left( {L\omega - {1 \over {C\omega }}} \right)}^2}} } \over R}
C) {{{\varepsilon ^2}R} \over {\sqrt {{R^2} + {{\left( {L - {1 \over {C\omega }}} \right)}^2}} }}
D) {{{\varepsilon ^2}R} \over {\left[ {{R^2} + {{\left( {L\omega - {1 \over {C\omega }}} \right)}^2}} \right]}}
488
MediumNEET2008
In an a.c. circuit the e.m.f. ($\varepsilon ) and the current (i) at any instant are given respectively by \varepsilon = E0sin\omega t, i = I0sin(\omega t - \phi $) The average power in the circuit over one cycle of a.c. is
Options:
A) {{{E_0}{I_0}} \over 2}\cos \phi
B) {{E_0}{I_0}}
C) {{{E_0}{I_0}} \over 2}
D) {{{E_0}{I_0}} \over 2}\sin \phi
489
MediumNEET2007
A transformer is used to light a 100 W and 110 V lamp from a 220 V mains. If the main current is 0.5 amp, the efficiency of the transformer is approximately
Options:
A) 50%
B) 90%
C) 10%
D) 30%
490
MediumNEET2007
What is the value of inductance L for which the current is maximum in a series LCR circuit with C = 10 $\mu F and \omega = 1000 s-$1 ?
Options:
A) 1 mH
B) cannot be calculated unless R is known
C) 10 mH
D) 100 mH
491
MediumNEET2007
The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux $\phi linked with the primary coil is given by \phi = \phi 0 + 4t, where \phi is webers, t is time in seconds and \phi $0 is a constant, the output voltage across the secondary coil is
Options:
A) 120 volt
B) 220 volts
C) 30 volts
D) 90 volts.
492
MediumNEET2006
A coil of inductive reactance 31 $\Omega has a resistance of 8 \Omega . It is placed in series with a condenser of capacitative reactance 25 \Omega $. The combination is connected to an a.c. source of 110 V. The power factor of the circuit is
Options:
A) 0.33
B) 0.56
C) 0.64
D) 0.80
493
MediumNEET2006
A transistor-oscillator using a resonant circuit with an inductor L (of negligible resistance) and a capacitor C in series produce oscillations of frequency $f$. If L is doubled and C is changed to 4C, the frequency will be
Options:
A) f/2
B) f/4
C) 8f
D) f/2\sqrt 2
494
MediumNEET2006
The core of a transformer is laminated because
Options:
A) ratio of voltage in primary and secondary may be increased
B) energy losses due to eddy currents may be minimised
C) the weight of the transformer may be reduced
D) rusting of the core may be prevented.
495
MediumNEET2005
In a circuit L, C and R are connected in series with an alternating voltage source of frquency $f.$ The current leads the voltage by 45o. The value of C is
Options:
A) {1 \over {\pi f\left( {2\pi f\,L - R} \right)}}
B) {1 \over {2\pi f\left( {2\pi f\,L - R} \right)}}
C) {1 \over {\pi f\left( {2\pi f\,L + R} \right)}}
D) {1 \over {2\pi f\left( {2\pi f\,L + R} \right)}}
496
MediumNEET2004
A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is
Options:
A) 5 seconds
B) 1/5 seconds
C) 40 seconds
D) 20 seconds
497
MediumNEET2002
For a series LCR circuit the power loss at resonance is
Options:
A) {{{V^2}} \over {\left[ {\omega L - {1 \over {\omega C}}} \right]}}
B) {I^2}L\omega
C) {I^2}R
D) {{{V^2}} \over {C\omega }}
498
MediumNEET2001
A capacitor of capacity C has reactance X. If capacitance and frequency become double then reactance will be
Options:
A) 4X
B) X/2
C) X/4
D) 2X
499
MediumNEET2001
The value of quality factor is
Options:
A) {{\omega R} \over L}
B) {1 \over {\omega RC}}
C) \sqrt {LC}
D) L/R
500
MediumVITEEE2024
A transformer has 200 windings in the primary and 400 windings in the secondary. The primary is connected to an AC supply of 110 V and a current of 10 A flows in it. The voltage across the secondary and the current in it, respectively, are
Options:
A) 55 \mathrm{~V}, 20 \mathrm{~A}
B) 440 \mathrm{~V}, 5 \mathrm{~A}
C) 220 \mathrm{~V}, 10 \mathrm{~A}
D) 220 \mathrm{~V}, 5 \mathrm{~A}
501
MediumVITEEE2024
Which of the following graphs represents the correct variation of inductive reactance X_L with angular frequency \omega ?
Options:
A)
B)
C)
D)
502
MediumVITEEE2024
In an electric circuit, a capacitor of reactance 55 \Omega is connected across the source of 220 V . The value of displacement current is
Options:
A) 2 A
B) 4 A
C) 6 A
D) 8 A
503
MediumVITEEE2024
The primary of a transformer has 400 turns while the secondary has 2000 turns. If the power output from the secondary at 1000 V is 12 kW . The resistance of the primary is 0.2 \Omega and that of the secondary is 2 \Omega. If the efficiency of the transformer is 80 \%, then the power loss in the primary is
Options:
A) 288 W
B) 1125 W
C) 2000 W
D) 725 W
504
MediumVITEEE2021
The alternating current in a circuit is given by $I=50 \sin 314 t$. The peak value and frequency of the current are
Options:
A) I_0=25 \mathrm{~A} and f=100 \mathrm{~Hz}
B) I_0=50 \mathrm{~A} and f=50 \mathrm{~Hz}
C) I_0=50 \mathrm{~A} and f=100 \mathrm{~Hz}
D) I_0=25 \mathrm{~A} and f=50 \mathrm{~Hz}
505
MediumVITEEE2021
A $50 \mathrm{~Hz} \mathrm{AC} signal is applied in a circuit of inductance of (1 / \pi) \mathrm{H} and resistance 2100 \Omega$. The impedance offered by the circuit is
Options:
A) 1500 \Omega
B) 1700 \Omega
C) 2102 \Omega
D) 2500 \Omega
506
MediumVITEEE2021
If the alternating current $I=I_1 \cos \omega t+ I_2 \sin \omega t$ then the rms current is given by
Options:
A) \frac{I_1+I_2}{\sqrt{2}}
B) \frac{\left|I_1+I_2\right|}{\sqrt{2}}
C) \sqrt{\left(\frac{I_1^2+I_2^2}{2}\right)}
D) \sqrt{\frac{I_1^2+I_2^2}{\sqrt{2}}}
506
Total Questions
87
Easy
412
Medium
7
Hard
Study Tips
Before You Start
- • Review the chapter concepts thoroughly
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- • Practice similar problems from your textbook
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After Practice
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- • Make notes of common mistakes
- • Practice similar questions again later