Question

3 Two point charges separated by a distance d repel each other with a force of 9 N. If the separation between
becomes 3d, the force of repulsion will be
(1) IN
(3) 6N
(2) 3N
(4) 27 N

Answer 1

F is invertionaly propotional to R^2. F1/F2=R2^2/R1^2,. here F1=9N, F2=?, R1=d, R2=3d,. 9/F2=(3d)^2/d^2,. , 9/F2=9d/d,. F2=1N