A charge Q is uniformly distributed over a large plastic plate. The electric field at a point P close to the centre of the plate is 10 V / m. If the plastic plate is replaced by a copper plate of the same geometrical dimensions and carrying the same charge Q, the electric field (in V / m ) at the point P will become -

Question

A charge Q is uniformly distributed over a large plastic plate. The electric field at a point P close to the centre of the plate is 10 V / m. If the plastic plate is replaced by a copper plate of the same geometrical dimensions and carrying the same charge Q, the electric field (in V / m ) at the point P will become - (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

For a non conducting plate vec E =(σ/2 ε0) hat n =10 V / m for conducting plate of copper vec E =(σ/ε0) hat n =20 V / m

For a non conducting plate E=2ε0​σ​n^=10V/m for conducting plate of copper E=ε0​σ​n^=20V/m

For a non conducting plate
$E = \frac{σ}{2 ε _{0}} \overset{n}{^} = 10 V / m$
for conducting plate of copper
$E = \frac{σ}{ε _{0}} \overset{n}{^} = 20 V / m$