Q150 / 150 · MHT CET 2009 · Physics
An alternating volta ge $E=200 \sqrt{2} \sin (100 t)$ is connected to 1 microfarad capacitor through AC ammeter. The reading of ammeter shall be
- A$10 \mathrm{~mA}$
- Correct answerB$20 \mathrm{~mA}$
- C$40 \mathrm{~mA}$
- D$80 \mathrm{~mA}$
Solution
Reading of ammeter $=I_{\mathrm{rms}}=\frac{V_{\mathrm{rms}}}{X_{C}}=\frac{V_{0} \omega C}{\sqrt{2}}$
$$
\begin{array}{l}
=\frac{200 \sqrt{2} \times 100 \times\left(1 \times 10^{-6}\right)}{\sqrt{2}}=2 \times 10^{-2} \mathrm{~A} \\
=20 \mathrm{~mA}
\end{array}
$$
Hence, the correct answer is option: 'B'.