Given:

Magnitude of charge on both proton and electron,

The radius of the circular orbit,

Mass of electron ,

The radius of the circular orbit is the distance between the electron and the proton.

___________________________________________________

Formula used:

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

Where ϵ₀ is the permittivity of free space

q₁ and q₂ are the magnitude of charges

r is the distance of separation between the charges

(Here, )

___________________________________________________

The magnitude of electric force is given by:

___________________________________________________

Formula used:

Centripetal force is given by

Where m is the mass if the object, v is the speed of the object and r is the radius of the circular path.

___________________________________________________

Let F_c be the centripetal force on the electron.

Now, the electric force acts as centripetal force.

Hence,

Substituting (1) and rearranging, we get

Putting the values in the above formula, we get