Question

A given charge situated at certain distance from an electric dipole in the end on position, experiences a force F. If the distance of charge is doubled, the force acting on the charge will be

• A. $2F$
• B. $F/2$
• C. $F/4$
• D. $F/8$

Answer 1

The correct option is D $F/8$

In case of electric dipole

$F\propto \frac{1}{r^3}$

So, $F=\frac{k}{r^3}$ ...(i)

According to question

$F^{\prime }=\frac{k}{(2r{)}^3}=\frac{k}{8r^3}$ ...(ii)

From Eqs. (i) and (ii), we get $F^{\prime }=\frac{F}{8}$