Question

An inductor $L$, a resistance $R$ and two identical bulbs $B_1$ and $B_2$ are connected to a battery through a switch $S$ as shown in the figure. The resistance of coil having inductance $L$ is also $R$. Which of the following statement gives the correct description of the happenings when the switch $S$ is closed?

• A. The bulb $B_2$ lights up earlier than $B_1$ and finally both the bulbs shine equally bright.
• B. $B_1$ light up earlier and finally both the bulbs acquire equal brightness.
• C. $B_2$ lights up earlier and finally $B_1$ shines brighter than $B_2$.
• D. $B_1$ and $B_2$ light up together with equal brightness all the time.

Answer 1

The correct option is A The bulb $B_2$ lights up earlier than $B_1$ and finally both the bulbs shine equally bright.

The two parallel paths are independent. Final current in both the paths will be same. Due to presence of inductance, the growth of current in $B_1$ gets delayed.