Q 12-01-009NEETJEE MainEasy
Two identical point charges repel each other with a force $F$ when $r$ apart. If the charge on each is doubled and the separation is halved, the force becomes
Answer: (A) $16F$
Concept. Coulomb's law: $F \propto \dfrac{q^2}{r^2}$.
Step 1. Factor. $\dfrac{2^2}{(1/2)^2} = 16$.
Answer. $16F$ (Option A).
Solution by Sreeraj P, M.Sc Physics