Question

Two charged particles are placed 1.0 cm apart. What is the minimum possible magnitude of the electric force acting on each charge?

Answer 1

We know that minimum charge on a body (q) = charge on an electron
⇒ q = 1.6 × 10⁻¹⁹ C
Given:
Separation between the charges, r = 1 cm = 10^-2 m
By Coulomb's Law, force,     

\[F = \frac{1}{4\pi \epsilon_0}\frac{q_1 q_2}{r^2}\]

\[\Rightarrow F = \frac{9 \times {10}^9 \times \left( 1 . 6 \times {10}^{- 19} \right)^2}{\left( {10}^{- 2} \right)^2}\] 

\[ \Rightarrow F = 2 . 3 \times  {10}^{- 24}   N\]