Solved Example Problems on Displacement current and Maxwell’s correction to Ampere's circuital law

EXAMPLE 5.1

Consider a parallel plate capacitor which is maintained at potential of 200 V. If the separation distance between the plates of the capacitor and area of the plates are 1 and 20 cm2. Calculate the displacement current for the time in µs.

Solution

Potential difference between the plates of the capacitor, V = 200 V

The distance between the plates,

d = 1 mm = 1 × 10-3 m

Area of the plates of the capacitor,

A = 20 cm2 = 20 × 10-4 m2

Time is given in micro-second, µs = 10-6 s

Displacement current

But electric field, E = V/d

Therefore,

 = 35400 ×10−7 = 3 .5 mA