Question

Two equal balls with equal positive charge 'q' coulombs are suspended by two insulating strings of equal length. What would be the effect on the force when a plastic sheet is inserted between the two?

Answer 1

Since plastic is an insulator, the electric field lines due to any of the charge will not be able to pass through it. In the absence of an external electric field due to the other charge, both the charges will not experience any force due to each other.