Question

A charge $Q$ is uniformly distributed over a large plastic plate. The electric field at a point $P$ close to the the centre of the plate is $20V{m}^{-1}$. If the plastic plate is replaced by a copper plate of the same geometrical dimensions and carrying the same charge $Q$, the electric field at the point $P$ will become

• A. $Zero$
• B. $10V{m}^{-1}$
• C. $20V{m}^{-1}$
• D. $40V{m}^{-1}$

Answer 1

Answer: (C)

$20V{m}^{-1}$

Since, the charge density of plastic and copper are the same so the electric field will be equal in both substances.

Thus, the electric field at the point P will become 20V/m.