Question

The inductice reactance for a coil of inductance `5 mH` when an alternating source of 220 V, 50 Hz is connected to it is `X_(1)`. The inductive reactance for the same coil connected to it is `X_(1)`. The inductive reactance for the same coil connected to a battery of e.m.f. 220 V is `X_(2)`. The ratio `X_(1)//X_(2)` is
A. 1
B. `pi/2`
C. `oo`
D. zero

Answer 1

Correct Answer - C
For a.c., Inductive reactance `X_(L) = omegaL = 2 pi fL`
For d.c., `f =0 :. Omega = 2 pi f = 0 :. X_(2)=0`
`:. (X_1)/(X_2) = (omega L)/(0) = oo`.