Two point charges A and B, having charges +Q and -Q respectively, are placed at certain distance apart and force acting between them is F, if `25%` charge of A is transferred to B, then force between the charges becomes:

Options

A. `(4F)/3`
B. F
C. `(9F)/16`
D. `(16F)/9`

Answer

C

Explanation

Let `Q_1` and `Q_2` be the new values of charges on A and B respectively ,
`Q_1`=Q-Q/4 =3Q/4
`Q_2`=-Q+Q/4 =-3Q/4
`F=(kQ^4)/r^2`
`F.=(k("3Q"/4)("3Q"/4))/r^2=9/16 (kQ^2)/r^2`
`rArr` F.=9F/16