The deuteron is bound by nuclear forces just as H-atom is made up of p and e bound by electrostatic forces. If we consider the force between neutron and proton in deuteron as given in the form of a Coulomb potential but with an effective charge e’:
Estimate the value of (e’/e) given that the binding energy of a deuteron is 2.2 MeV.
The value of 
Given
The force between neutron and proton is given by
, the binding energy of the deuteron is
.
Formula used
Binding Energy of H-atom orbital derived from Schrödinger equation. The Schrödinger equation states the wave function of a quantum mechanical system by the use of linear partial differential equation.
For H-atom 
For Deuteron 
where
E and E’ are the binding energy for H-atom and Deuteron respectively, m is the mass of proton, m’ is the reduced mass of proton and neutron 
e’ is the effective charge of deuteron and e is the charge of H-atom, h is the planks constant = 
Explanation
The binding energy of the H-atom is 
The binding energy of H-atom is known as 
Hence,
The binding energy of the deuteron is 
The binding energy of deuteron is known as 
Hence,
To find the value of reduced mass m’ in term of m we use the formula
where
is the mass of proton and neutron respectively.
So the binding energy of deuteron is
Equating both the binding energy in a ratio we get;
Solving the equation in terms of 
, the result is
Therefore, the value of 