Q124 / 200 · NEET 2009 (Screening) · Physics
Three capacitors each of capacitance $C$ and of breakdown voltage $V$ are joined in series. The capacitance and breakdown voltage of the combination will be
- A$\frac{\mathrm{C}}{3}, \frac{\mathrm{V}}{3}$
- B$3 \mathrm{C}, \frac{\mathrm{V}}{3}$
- Correct answerC$\frac{\mathrm{C}}{3}, 3 \mathrm{~V}$
- D$3 \mathrm{C}, 3 \mathrm{~V}$
Solution
In series arrangement charge on each plate of each capacitor has same magnitude.
The potential difference is distributed inversely in the ratio of capacitors ie,
$$
\mathrm{V}=\mathrm{V}_1+\mathrm{V}_2+\mathrm{V}_3 \ldots
$$
Here, $V=3 V$
The equivalent capacitance $\mathrm{C}_s$ is given by

$$ \begin{aligned} & \frac{1}{C_s}=\frac{1}{C_1}+\frac{1}{C_2}+\frac{1}{C_3}+\ldots \\ & C_s=\frac{\mathrm{C}}{3} \end{aligned} $$

$$ \begin{aligned} & \frac{1}{C_s}=\frac{1}{C_1}+\frac{1}{C_2}+\frac{1}{C_3}+\ldots \\ & C_s=\frac{\mathrm{C}}{3} \end{aligned} $$
Hence, the correct answer is option: 'C'.