Question

The displacement current is

• A. ${\epsilon }_o\frac{d{\varphi }_E}{dt}$
• B. $\frac{{\epsilon }_o}{R}\frac{d{\varphi }_E}{dt}$
• C. ${\epsilon }_o\frac{E}{R}$
• D. ${\epsilon }_{o}q\frac{C}{R}$

Answer 1

Answer: (A)

${\epsilon }_o\frac{d{\varphi }_E}{dt}$

Displacement current appears in the Maxwell's equation defined as the rate of change of electric displacement field. However there is no electric current of moving charges, but a time varying electric field.

It is given by $I_D={ϵ}_0\frac{d{\varphi }_E}{dt}$

where ${\varphi }_E$ is the electric flux at the point.