Question

an isolated conducting sphere is given a positive charge . does its mass increase , decrease.or remain same?

Answer 1

The mass of an isolated conducting sphere decreases due to the loss of electrons. Because the sphere is positive, so it should have lost electrons.

Answer 2

Explanation:

A conducting sphere isolated in nature gains a positive charge, then mass of the sphere is decreased. The isolated conducting sphere gains positive charge, that is, the positive charge is gained at the expense of electrons that implies loss of electrons in order to gain positive charge. The loss of electrons signifies the loss of mass of electrons lost.  

Therefore, the mass of conducting sphere in isolation is however insignificantly decreased based on the significant charge gained.