Two identical charged spheres separated by a distance repel other with a force F. If 10% of electrons are transferred from one sphere of the other ,then the force between them becomes

Options

A. F
B. 1.21 F
C. 0 . 99 F
D. 0 . 81 F

Answer

C

Explanation

According to the question,
Force, between these charged sphere,
` F = (k(q)(q))/(r^(2)) = (kq^(2))/(r^(2))`
If 10% of electrons are transferred from one sphere to the other then the charge on one sphere become
`(q +(q)/(1)) = (11q)/(110)` and charge on other sphere become
`(q - (q)/(10)) = (9q)/(10)`
Hence, force between them
`F.(k((9q)/(10))((11q)/(10)))/(r^(2)) = ((kq^(2))/(r^(2))) ((99)/(100)) rArr F. = 0.99 F `