Question

There are several pair of material when they are rubbed with each other, equal and opposite charges are transferred. How will you explain conservation of charges?

Answer 1

It is important to note that the two bodies being rubbed must be made up of different material having different electron affinity now when two bodies are rubbed some amount of electrons move from one body to another because of different electron affinity, which means the body losing electron will be positively charged at the same time that amount of electron will be gained by other body making it negatively charged so the amount of total charge remain conserved for the system.
ie,electron lost by a material=electron gained by a material.
So it holds law of conservation of charge