A certain charge `Q` is divided into two parts (q) an `(Q-q)`. Later on the charges are placed at a certain distance. If the force of interaction between the charges is maximum then

Options

A. Q=2q
B. Q=3q
C. Q=4q
D. Q=4q+c

Answer

a

Explanation

The electrostacitc force of repulsion between the charge and (Q-q) at separation r is given by
`F=(1)/(4piepsilon_(0))(qQ-q)/(r^(2))=(1)/(4piepsilon_(0)).(Q-2q)/(r^(2))=0`
as `(1)/(4piepsilon_(0)r^(2)) is constant, therefore,Q -2q=0 or Q=2q`