Question

Figure represents two bulbs $B_1$ and $B_2$, resistor R and an inductor L. When the switch S is turned off

• A. Both $B_1$ and $B_2$ die out promptly
• B. Both $B_1$ and $B_2$ die out with some delay
• C. $B_1$ dies out promptly but $B_2$ with some delay
• D. $B_2$ dies out promptly but $B_1$ with some delay

Answer 1

Answer: (C)

$B_1$ dies out promptly but $B_2$ with some delay.

Bulb $B_1$ dies out promptly, but bulb $B_2$ dies out with some delay. This is because self-induced emf across L supplies current through the bulb $B_2$, during decay.