Two equal balls having equal positive charges 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 beteween the two?

Explanation

From Coulomb.s law, electric force between the two charged bodies in a medium
` " " F = ( 1)/(4 piin _0) (| q_1q_2|)/(r^(2))`
where , K = dielectric constant of the medium
For vacuum , K = 1
For plastic , K > 1
Therefore , after insertion of plastic sheet , the force between the two balls will reduce.