Question

Two identical charges q and of mass m are at distance d. If both are at rest under the forces. Find value of q/m

Answer 1

$\frac{q}{m}=d\,\sqrt{\frac{g}{k\,m}}$

Answer 2

1. Write the Coulomb force as $kq^2/d^2$.

2. Equate it to $mg$ (the “balancing” force).

3. Solve for $q$ and then find $q/m$.

This approach is well suited for a 12th grade student preparing for JEE/NEET.