Question

An oscillating voltage of fixed amplitude is applied across a circuit element. If the frequency of this voltage is increased, the amplitude of the current will *

a)increase if the circuit element is either an inductor or a capacitor.

b)decrease if the circuit element is either an inductor or a capacitor.

c)increase if the circuit element is an inductor, but decrease if the circuit element is a capacitor.

d)decrease if the circuit element is an inductor, but increase if the circuit element is a capacitor.

e)More than one of the above is possible, depending on circumstances.

Answer 1

Reactance of a capacitor, Xc = 1/[2$\pi$fC]
So reactance of a capacitor will decrease if the frequency is increased and the amplitude of the current will increase.
Reactance of an inductor, XL = 2$\pi$fL
For an inductor, reactance will increase with the frequency. So if frequency is increased, amplitude of the current will decrease.

So the answer is d