Q.

To produce an instantaneous displacement current of 2 mA in the space between the parallel plates of a capacitor of capacitance 4 μF, the rate of change of applied variable potential difference (dVdt) must be            [2023]
 

1 800 V/s  
2 500 V/s  
3 200 V/s  
4 400 V/s  

Ans.

(2)

Displacement current, ID=ε0dϕEdt=ε0ddt(EA)

=ε0Addt(Vd)  or  ID=ε0AddVdt

  ID=CdVdt  or  dVdt=IDC

Given, ID=2mA=2×10-3A; C=4×10-6F

So, dVdt=2×10-34×10-6=500V/s