Question

An alternating voltage source of variable angular frequency ‘w’ and fixed amplitude ‘V’ is connected in series with a capacitance C and electric bulb of resistance R(inductance zero). When ‘w’ is increased ______.

Options

• The bulb glows dimmer.

• The bulb glows brighter.

• Net impedance of the circuit remains unchanged.

• Total impedance of the circuit increases.

Answer 1

An alternating voltage source of variable angular frequency ‘w’ and fixed amplitude ‘V’ is connected in series with a capacitance C and electric bulb of resistance R(inductance zero). When ‘w’ is increased the bulb glows brighter.

Explanation:

`omega uparrow`

`"X"_"c" = 1/(2pi"fc") = 1/(omega "c")` ↓ i.e. `"X"_"c" ↓`

I ↑ ∴ Brightness of the bulb will ↑.