Question

What is the force between two small charged spheres having charges of 2 × 10^-7 C and 3 × 10^-7 C placed 30 cm apart in air?

Answer 1

Given q₁ = 2 × 10^-7 C, q₁ = 3 × 10^-7 C

r = 30 cm = 0.3 m

Force of repulsion

\(F = 9\times10^9\frac{q_1q_2}{r^2}\)

= \(9\times10^9\times\frac{2\times10^{-7}\times3\times10^{-7}}{(0.3)^2}\)

= \(\frac{54\times10^{-5}}{9\times10^{-2}}\) = 6 x 10^-3 N