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, q₂ = 3 × 10⁻⁷ C and
r = 30 cm = 0.3 m, F = ?

F = `1/(4piε_0) * ("q"_1"q"_2)/"r"^2`

= `9 xx 10^9 xx (2 xx 10^-7 xx 3 xx 10^-7)/(0.3)^2`

= 6 × 10^-3 N (repulsive in nature, as the two charges are like charges.)