Question

In the following circuit the emf of source is $E_{0}=200$ volt, $R=20 \,\Omega, L=0.1$ henry, $C=10.6$ farad and frequency is variable then the current at frequency $f=0$ and $f=\infty$ is

• A. Zero, 10 A
• B. 10 A, zero
• C. 10 A, 10 A
• D. Zero, zero

Answer 1

Answer: (D)

$E_{0}=200$ volt, $R=20 \,\Omega, L=0.1$ henry, $C=10.6 \,F$
When $f=0, X_{L}=\omega L=2 \pi f L$
$X_{L}=0$
When $f=\infty, X_{L}=\infty, x_{C}=0$
In both case at least one component has value infinite.
So in both cases current will be zero as they are connected in series.