Pyq- Electromagnetic Induction & Alternating Currents L10

Question: An inductor of inductance $2 \mathrm{mH}$ is connected to a $220 \mathrm{~V}, 50 \mathrm{~Hz}$ ac source. Let the inductive reactance in the circuit is $X_1$. If a $220 \mathrm{~V}$ dc source replace the ac source in the circuit, then the inductive reactance in the circuit is $X_2 . X_1$ and $X_2$ respectively are: (NEET-2022)#

A) $0.628 \Omega$, infinity

B) $6.28 \Omega$, zero

C) $6.28 \Omega$, infinity

D) $0.628 \Omega$, zero

Answer: $0.628 \Omega$, zero#

Explanation#

We know, for A.C. source

$ X_L=\omega L$

$=2 \pi f(L)$

$=100 \pi\left(2 \times 10^{-3}\right)$

$=0.2 \pi \Omega=0.628 \Omega$

For D.C. source

The inductor behaves as a closed circuit offering no resistance at all (at steady state) as $\omega=0$ (For D.C.)

$\therefore X_L=0 \Omega$