A variable frequency a.c. source is connected to a capacitor. What is the effect on the displacement current `(I_d)` when the frequency of the a.c. source is increased from 500 Hz to 1000 Hz?

Options

A. `I_(d)` will remain constant
B. `I_(d)` will decrease
C. `I_(d)` will be doubled
D. `I_(d)` will become half

Answer

C

Explanation

The reactance of a capacitor `X_(C) = 1/(omega C) = 1/(2 pi f C)`
If the frequency is increased, the reactance is decreased and hence the current (I) is increased.
As displacement current `(I_d)`= coduction current
`I_(d)` will be doubled if the frequency is doubled.