Question

Two capacitors $C_1\text{and}{C}_2$ are charged to $120\text{V}\text{and}200\text{V}$ respectively. It is found that by connecting them together the potential on each one can be made zero. Then :

• A. $3C_1+5C_2=0$
• B. $9C_1=4C_2$
• C. $5C_1=3C_2$
• D. $3C_1=5C_2$

Answer 1

The correct option is D $3C_1=5C_2$



Charge on first capacitor, $Q_1=C_1{V}_1=120C_1$

Charge on first capacitor, $Q_2=C_2{V}_2=120C_2$

Connecting both of them. If potential on both of them become zero then
$Q_1=Q_2$

$\Rightarrow 120C_1=200C_2$

$\Rightarrow 3C_1=5C_2$

Hence, option $\left(B\right)$ is correct.