Question

Two charges `+4e` and `+e` are at a distance `x` apart. At what distance,a charge `q` must be placed from charge `+e` so that is in equilibrium
A. `x//2`
B. `2x//3`
C. `x//3`
D. `x//6`

Answer 1

Correct Answer - c
For equilibrium of `q`
`|F_(1)|=|F_(2)|`

Which gives `x_(2)==(x)/(sqrt(Q_(1)/(Q_(2)))+1)=(x)/(sqrt(4e)/(e)+1)=(x)/(3)`