Two spheres carrying charges `+ 6 mu C and 9 mu C ` , seperated by a distance d , experience a force of repulsion F . When a charge of ` - 3 mu C ` is given to both the sphere and kept at the same distance as before , the new force of repulsion is

Options

A. F/9
B. F/3
C. 3F
D. F

Answer

B

Explanation

`F= (k xx 6 xx 9)/(d^(2))` SI units
`F^(1)= (k xx 3 xx 6)/(d^(2))` SI units `rArr (F^(1))/(F)= (1)/(3) rArr F^(1) = F//3`