Question

$V_R\&V_C$ are output voltages across the resistor and capacitor respectively. Choose a correct option.

• A. As frequency of source increases, $V_C$ increases.
• B. As frequency of source increases, $V_C$ decreases.
• C. $V_R$ is independent of frequency.
• D. $V_R$ decreases with an increment in frequency.

Answer 1

The correct option is B As frequency of source increases, $V_C$ decreases.

$V_R=iR\&i=\frac{\epsilon }{z}=\frac{\epsilon }{\sqrt{R^2+x_c^2}}$
$x_c=\frac{1}{\omega c}$

With an increment in $\omega$, $x_c$ decreases, so $i$ increases; hence, $V_R$ increases. Also, $\epsilon =\sqrt{V_R^2+V_C^2}$, so as $V_R$ increases, $V_c$decreases.