Two charged particles repel each other with a force F. If the charge of one of the particles is doubled and the distance between them is also doubled, then the force will be
A)F.
B)2 F.
C)F/2.
D)F/4.
E)none of the above

Question

Quizplus · Accepted Answer

According to Coulomb's law, the force between two charges is inversely proportional to the square of the distance between them. Therefore, if the distance is doubled, the force will become 1/4 of the original force. On the other hand, if the charge of one of the particles is doubled, the force will be doubled. Therefore, the net effect of these changes is that the force becomes F/2.

Two Charged Particles Repel Each Other with a Force F