Two identical metals balls with charges `+2Q` and `-Q` are separated by some distance and exert a force `F` on each other . They are joined by a conducting wire , which is then removed. The force between them will now be

Options

A. F/2
B. F/6
C. F/4
D. F/8

Answer

D

Explanation

`F=k(2Q^(2))/(r^(2))`
New Change=
`(Q_(1)+Q_(2))/2=Q/2impliesF_(2)=(k(Q/2)^(2))/(r^(2))=F/8`