Question

Two point charges repel each other with a force of 100N. One of the charges is increased is increased by 10% and the other is reduced by 10% . The new force of repulsion at the same distance would be
A. 100N
B. 121N
C. 99N
D. none of these

Answer 1

Correct Answer - C
`100=kq_(1)q_(2)//r^(2)` and `F=k(1.1 q_(1))(0.9 q_(2))//r^(2)`
`implies (F)/(100) =0.99` or `F=99N`.