Two insulating small spheres are rubbed against each other and placed 1 cm apart. If they attract each other with a force of 0.1N, how many electrons were transferred from one sphere to the other during rubbing?

Given,

Electric force between the two spheres,

Distance between the two spheres,

We know that, magnitude of charge on electron,

Let n electrons be transferred from one sphere to another. Then, charge on one sphere is +ne and the other is -ne.

________________________________________________

Formula used:

By Coulomb’s law, the electric force is given by:

Where ϵ₀ is the permittivity of free space

k is the electrostatic constant

q₁ and q₂ are the magnitude of charges

r is the distance of separation between the charges

__________________________________________________

The magnitude of electric force is given by:

Hence, about electrons are transferred.