Two point charger `+8 mu` and `+12 mu` repel each other with a force of 48 N. When an additional charge of `-10 mu` is given to each of these charges (the distance between the charges is unaltered) then the new force is

Options

A. repulsive force of 24 N
B. attractive force of 24 N
C. repulsive force of 12 N
D. attractive force of 2 N

Answer

C

Explanation

Given, `q_(1)=+3muC, q_(2)=+12muC "and" F_(1)=48 N`
When an amount of charge `-10muC` is added to both of the charges then, these becomes
`q_(1)=-2muC "and" q_(2)=+2muC`
The force between two charges,
`Fprop|q_(1)q_(2)|`
`RightarrowF_(1)prop|q_(1)q_(2)| "and" F_(2)prop|q_(1)^(1)q_(2)^(2)|`
and `(F_1)/(F_2)=(q_(1)q_(2))/(q_(1)q_(2))Rightarrow(48)/(F_(2))=(8xx12)/(2xx2)`
`RightarrowF_(2)=2N`