Question

An alternating voltage of $E=200\sqrt{2}sin\left(100t\right)V$ is connected to a condenser of 1 $\mu$ F through an A.C. ammeter. The reading of the ammeter will be

• A. 10 mA
• B. 40 mA
• C. 80 mA
• D. 20 mA

Answer 1

The correct option is D 20 mA

An alternating voltage $E=200\sqrt{2}sin\left(100t\right)V$
$⟹w=100$ and $V_{max}=200\sqrt{2}$
Current in the ammeter

$i=\frac{V_{rms}}{1/\omega C}$

where $V_{rms}=\frac{V_{max}}{\sqrt{2}}$

$i=\frac{V_{max}\times \omega C}{\sqrt{2}}$
$i=\frac{200\sqrt{2}\times 100\times {10}^{-6}}{\sqrt{2}}$
$i=2\times {10}^{-2}$ A
$i=20$mA