Q. A charge is uniformly distributed over a large iron plate. The electric field at a point close to the centre of the plate is . If the iron plate is replaced by a copper plate of the same geometrical dimensions and carrying the same charge, then the electric field at the same point will be

 2343  220 Electric Charges and Fields Report Error

Solution:

(for metal plate)
is the surface charge density. It does not depend on the type of conductor.