Question

Two charges of magnitude 10 units and 20 units are separated by a certain distance. Now, both the charges are brought in contact and again separated to initial separation. What will be the ratio of initial and final electrostatic force?

• A. $\frac{9}{8}$
• B. $\frac{4}{3}$
• C. $\frac{3}{2}$
• D. $\frac{8}{9}$

Answer 1

The correct option is D $\frac{8}{9}$

$F_i=\frac{1}{4\pi {\in }_0}\frac{\left(10\right)\left(20\right)}{r^2}$
$F_f=\frac{1}{4\pi {\in }_0}\frac{\left(15\right)\left(15\right)}{r^2}$