Question 10: Current Electricity

Question

In the adjoining circuit diagram, the
readings of ammeter and voltmeter are 2 A
and 120 V, respectively. If the value of R is
75$$\Omega$$, then the voltmeter resistance will be

Accepted Answer

$$\because V_{A B}=\left(I-I_gight) R=I_g \cdot G$$
where, G = voltmeter (resistance).
$$\begin{array}{ll}
	ext { Given, } & V_{A B}=120 \mathrm{~V}, I=2 \mathrm{~A}, R=75 \Omega \\
\Rightarrow & 120=\left(2-I_gight) 75 \Rightarrow I_g=0.4 \mathrm{~A} \\
	ext { Now, } & V_{A B}=I_g G \Rightarrow G=\frac{120}{0.4}=300 \Omega
\end{array}$$

Answer

100 $$\Omega$$

Answer

150 $$\Omega$$

Answer

300 $$\Omega$$

Answer

75 $$\Omega$$

Current Electricity

In the adjoining circuit diagram, the readings of ammeter and voltmeter are 2 A and 120 V, respectively. If the value of R is 75$\Omega$, then the voltmeter resistance will be

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