Q146 / 160 · AP EAMCET 2023 (15 May Shift 2) · Physics
Two capacitors of capacity $4 \mu \mathrm{F}$ and $6 \mu \mathrm{F}$ are connected in series to a $500 \mathrm{~V}$ battery.
The potential difference across $4 \mu \mathrm{F}$ capacitor is
- A$200 \mathrm{~V}$
- Correct answerB$300 \mathrm{~V}$
- C$400 \mathrm{~V}$
- D$500 \mathrm{~V}$
Solution
$\begin{aligned}
& \mathrm{C}_1=4 \mu \mathrm{F} \text { and } \mathrm{C}_2=6 \mu \mathrm{F} \\
& \mathrm{C}_{\text {eq }}=\frac{\mathrm{C}_1 \mathrm{C}_2}{\mathrm{C}_1+\mathrm{C}_2} \\
& =\frac{4 \times 6}{4+6}=2.4 \mu \mathrm{F} \\
& \mathrm{Q}=\mathrm{C}_{\text {eq }} \mathrm{V} \\
& =2.4 \times 10^{-6} \times 500=1200 \times 10^{-6} \mathrm{C}
\end{aligned}$
The potential difference across $4 \mu \mathrm{F}$ capacitor is
$\begin{aligned}
& \Delta \mathrm{V}=\frac{\mathrm{Q}}{\mathrm{C}_1} \\
& =\frac{1200 \times 10^{-6}}{4 \times 10^{-6}}=300 \mathrm{~V}
\end{aligned}$
Hence, the correct answer is option: 'B'.