An AC 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

Options

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

B

Explanation

The impedance of the R-C circuit is
`Z = sqrt(R^(2)+1/(omega^(2)C^(2)))`
If `omega` is increased, Z is decreased.
`:.` The current will increase.
`:.` The power of bulb `prop ("current")^(2)`
`:.` The bulb will glow brighter.