Question

An $A C$ voltage source of variable angular frequency $\omega$ and fixed amplitude $V_{0}$ is connected in series with a capacitance $C$ and an electric bulb of resistance $R$ (inductance zero). When $\omega$ is increased

• A. the bulb glows dimmer
• B. the bulb glows brighter
• C. total impedance of the circuit is unchanged
• D. total impedance of the circuit increases

Answer 1

Answer: (B)

Impedance $Z=\sqrt{\frac{1}{(\omega C)^{2}}+R^{2}}$
as $\omega$ increases, $Z$ decreases.
Hence bulb will glow brighter