Question

Two point charges `+9e` and `+e` are kept `16 cm`. Apart from each other. Where should a third charge `q` be placed between them so that the system is in equlibrium state:
A. `24 cm` form `+9e`
B. `12 cm` from `+9e`
C. `24 cm` from `+e`
D. `12 cm` from `+e`

Answer 1

Correct Answer - b
`(K(9e)q)/(r^(2))= (keq)/((16-r))implies 3/r= 1/(16-r)implies r= 12cm`