Question

An unchanged capacitor is connected in circuit as shown in figure. Power ratings of bulbs are given in diagram. At $t=0$ switch is closed select correct alternatives :

• A. At $t=0$ power consumption in circuit is $\frac{3P_0}{2}$
• B. After a long time power consumption in circuit is $\frac{P_0}{2}$
• C. Brightness of $B_1$ decreases with time.
• D. Initially Brightness of bulb $B_2$ is less than brightness of $B_1$, but later on after certain time $B_2$ will be brighter.

Answer 1

The correct option is D Initially Brightness of bulb $B_2$ is less than brightness of $B_1$, but later on after certain time $B_2$ will be brighter.

At $t=0$
(see image 1)
$P_{consume}=\frac{V_0^2}{2R/3}=\frac{3}{2}{P}_0$
After a long time : (see image 2)
$P_{consume}=\frac{V_0^2}{2R/3}=\frac{P_0}{2}$
Since current in $B_1$ decreases with time so brightness decreases.
Initially brightness of $B_2$ is less than $B_1$ but later on $B_2$ will be brighter.