is there any variation of mass of a charged body? give reason

In the process of charging a body either gains or looses electron to gain either positively or negatively charged. This transfer of electron does not bring any observable change in the mass of the body . Reason being, The mass of electron is being very small compared to the charged body.

However we calculate the change in the mass of a body due to charging process .

For example

A body mass M is given a charge +q , Since charge is quantized

Mass of the electron lost is = n * me

New mass of the body = M−n×me

Hence on charging a body the mass of the body is affected but undectectable change in the mass