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

Repulsive force of magnitude 6 × 10⁻³ N
Charge on the first sphere, q₁ = 2 × 10⁻⁷ C
Charge on the second sphere, q₂ = 3 × 10⁻⁷ C
Distance between the spheres, r = 30 cm = 0.3 m Electrostatic force between the spheres is given by the relation

Hence, force between the two small charged spheres is 6 × 10⁻³ N. The charges are of same nature. Hence, force between them will be repulsive.