Question

An ebonite rod is rubbed with wool. Does it gain or losses mass on charging

Answer 1

When you rub fur with ebonite rod, the chemical bond is formed between some parts of the the two surface. Rod has its electron more tightly bound than fur. So, fur donates electrons to the rod while electrons from rod won't come out. Due to excess of electrons in rod, it becomes negatively charged while the fur with lost electrons, becomes deficient of electrons. Thus, fur becomes positively charged.

Answer 2

When an ebonite rod is rubbed with fur then, it acquires a positive charge and the wool gains a negative charge. There is the changing in charge not in mass. But, if we calculate the mass of electron then, it is losing its mass.