Question 91: AC fundamentals

Question

For the given figures, choose the correct options :

Accepted Answer

For (a), $$i = {V \over R} = {{220} \over {40}} = 5.5\,A$$
for (b), $${X_C} = {1 \over {2\pi fC}} = {1 \over {2\pi  	imes 50 	imes 0.5 	imes {{10}^{ - 6}}}} = {{{{10}^6}} \over {50\pi }}\Omega $$
$${X_L} = 2\pi fL = 2\pi  	imes 50 	imes 50 	imes {10^{ - 3}} = 50\pi \,\Omega $$
$${X_C} > {X_L}$$, hence impedance is greater than 40 $$\Omega$$.
$${i_{rms}} = {{220} \over Z}$$
$$	herefore$$ $${\left. {{i_{rms}}} ight|_b} < {\left. {{i_{rms}}} ight|_a}$$

Answer

The rms current in circuit (b) can be larger than that in (a)

Answer

The rms current in figure (a) is always equal to that in figure (b)

Answer

The rms current in circuit (b) can never be larger than that in (a)

Answer

At resonance, current in (b) is less than that in (a)

AC fundamentals

For the given figures, choose the correct options :

Choose the correct answer: