Question

You are given a `2mu F` parallel plate capacitor. How would you establish an instantaneous displacement current fo 1mA in the space between its plates?
A. `100 V//s`
B. `300 V//s`
C. `500 V//s`
D. `750 V//s`

Answer 1

Correct Answer - C
The charge on the capacitor `q = VC`
But `q = I xx t`
In this case `I = I_(d)` and `t = dt` and beacuse we have to apply a varying P.D.
`:. I_(d)dt = CdV`
`:. I_(d) = C(dV)/(dt)`
`:. (dV)/(dt) = (I_d)/(C)`
But `I = 1 xx 10^(-3) A` and `C = 2 xx 10^(-6)F`
`:. (dV)/(dt) = (10^(-3))/(2 xx 10^(-6)) = 1000/2 = 500 V//s`.