A certain charge Q is divided into two parts q and `Q-q`, wheich are then separated by a cetain distance. What must q be in terms of Q to maximum the electrostatic repulsion between the two charges?

Options

A. 2
B. `1//2`
C. 4
D. `1//4`

Answer

A

Explanation

let distance between two charges is x.
the force between them.
`F=(1)/(4piepsi_(0))(q(Q-q))/(x^(2))`
xis constant, so for maximum force q(Q-q) should be maximum
`(d)/(dq){q(Q-q)}=0`
`Q-2q=0`
`implies(Q)/(1)=2`