Question

An inductor of inductance $2\, mH$ is connected to a $220 \, V , 50 \, Hz$ a.c. source. Let the inductive reactance in the circuit is $X _1$. If a $220\, V dc$ source replaces the ac source in the circuit, then the inductive reactance in the circuit is $X _2 . X _1$ and $X _2$ respectively are:

• A. $6.28\, \Omega$, zero
• B. $6.28\, \Omega$, infinity
• C. $0.628 \, \Omega$, zero
• D. $0.628\, \Omega$, infinity

Answer 1

Answer: (C)

For $A C X_L=\omega L$
$ X _1=100 \pi \times 2 \times 10^{-3} $
For DC, $\omega=0$
$ X _1=0.2 \pi \Omega$
$X_{ L }=\omega L $
$ X _2=0$
$ X _1=0.628 \Omega$