List of top Physics Questions on coulombs law asked in Manipal

Two charges are at a distance $d$ apart. If a copper plate of thickness $ \frac{d}{2} $ is kept between them, the effective force will be

Two copper balls, each weighing 10 g , are kept in air 10 cm apart. If one electron from every $10^6$ atoms is transferred from one ball to the other, the coulomb force between them is (atomic weight of copper is 63.5)