(ii) Choose the best appropriate explanation from the following
(a) To give the sphere a negative charge, we must give it more electrons and this will increase its mass.
(b) A positive charge increases the sphere's mass and a negative charge decreases its mass,
(c) Charge is conserved, therefore the mass of the object will remain the same.

An isolated conducting sphere is given a positive charge by rubbing. Its mass

A polythene piece rubbed with wool is found to have a negative charge of 1muC . Estimate the number of electrons transferred. Is there any transfer of mass from wool to polythene?

Predict and explain Gaussian surface A has twice the area of Gaussian surface B. Both surfaces enclose the same charge Q. Choose the best explanation from the following. (a) Gaussian surface B is closer to the charge, since it has the smaller area. It follows that it has the greater electric flux. (b) The two surfaces enclose the same charge and hence they have the same electric flux. (c ) Electric flux is proportional to the area Therefore , Gaussian surface A has the greater electric flux.

Two identical metallic spheres of exactly equal asses are taken. One is given a positive charge Q coulomb and the other an equal negative • charge. Their masses after charging are different.

The body is positively charged. Then its mass effectively.

Predict and explain. An electrically neutral sphere is given a negative charge. (1) In principle, does the object's mass increase, decrease or remain the same after being charged?