Question

Write the generalised expression for the Ampere’s circuital law in terms of the conduction current and the displacement current. Mention the situation when there is: 

(i) only conduction current and no displacement current. 

(ii) displacement current and no conduction current

Answer 1

Generalised Ampere’s circuital Law —

Line integral of magnetic field over closed loop is equal to m0 times sum of conduction current and displacement current.

(i) In case of steady electric field in a conducting wire, electric field does not change with time, conduction current exists in the wire but displacement current may be zero. So,

(ii) In large region of space, where there is no conduction current, but there is only a displacement current due to time varing electric field (or flux). So,