Q. A parallel plate capacitor of area $A=16\ \mathrm{cm^2}$ and separation between the plates 10 cm, is charged by a DC current. Consider a hypothetical plane surface of area $A_0=3.2\ \mathrm{cm^2}$ inside the capacitor and parallel to the plates. At an instant, the current through the circuit is 6A. At the same instant the displacement current through $A_0$ is _______ mA.
Numerical Question
This is a numerical-answer question. The correct answer is shown below.
Explanation
[Solution by Dr. Abubacker] The displacement current density is uniform and equals $\frac IA$ inside the capacitor, so $I_d=I\cdot\frac{A_0}A=6\times\frac{3.2}{16}=1.2$ A $=1200$ mA. Answer: 1200.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.