Question

Two condensers of capacity $0.3\mu F$ and $0.6\mu F$ respectively are connected in series. The combination is connected across a potential of $6$ volts. The ratio of energies stored by the condensers will be:

• A. $\frac{1}{2}$
• B. $2$
• C. $\frac{1}{4}$
• D. $4$

Answer 1

The correct option is B $2$

Since the capacitors are connected in series so charge flowing through them will be same.

Energy stored in first capacitor of capacitance $0.3\mu F$ is given by

$E_1=\frac{Q^2}{2C_1}$

$E_1=\frac{Q^2}{2\times 0.3}$

Energy stored in second capacitor of capacitance $0.6\mu F$ is given by

$E_2=\frac{Q^2}{2C_2}$

$E_2=\frac{Q^2}{2\times 0.6}$

Now ratio of energy stored by the condensers is given by

$\frac{E_1}{E_2}=\frac{2}{1}$