Question

An alternating voltage (in volts) is given by $V =200 \sqrt{2} \sin (100 t )$ is connected to a $1 \, \mu F$ capacitor through an ac ammeter. The reading of the ammeter will be

• A. $10 \,mA$
• B. $20 \,mA$
• C. $40 \,mA$
• D. $80 \,mA$

Answer 1

Answer: (B)

the current in the circuit containing capacitor is given $I = V / xc$ given $V _{0}=200 \times 2^{1 / 2} v$.
$X_{c}=1 / 100 \times 10 \times 10^{-6}=1000$ ohm.
$I_{0}=200 x \sqrt{2_{/1000}}=200 \sqrt{2} \,mA .$
But ammeter reads rms value of current.
therefore $I _{ RMS }=200 \times \sqrt{2} / \sqrt{2}$
$=0.02 A =20 \,mA$