91Ó°ÊÓ

The following diagram is provided.

A little metal sphere suspended on an insulating thread inside a bigger hollow conducting sphere is depicted in the illustration. The little sphere has a wire extending from it that does not contact the hollow sphere. A charged rod was used to transfer positive charge through the wire, then the rod was removed after touching the wire.

The usage of a charged rod to transfer positive charge to the wire is assumed. Because the wire is attached to the inner sphere and does not touch the outer hollow sphere, when the rod touches the wire, the positive charge will be transferred through the wire to the inner little sphere. As a result, the little sphere will have a positive charge.

Because the inner tiny sphere is positively charged as a result of the charge transfer from the rod, a negative charge will form on the inner surface of the hollow sphere to balance the positive charge on the small sphere. Because the net charge on the Gaussian surface through the conductor of the outer hollow sphere must be zero, the hollow sphere's inner surface develops a negative charge to balance the positive charge on the inner tiny sphere. With a negative charge magnitude equal to the positive charge on the inner sphere.

The hollow sphere's inner surface develops a negative charge from its outer surface (all extra charge settles on a conductor's surface), resulting in a positive charge on the larger sphere's outside. Consider a Gaussian surface outside the larger sphere to illustrate what I mean. It has a net positive charge on it (i.e., the charge on the smaller sphere, since the larger sphere is overall neutral). Because the charge on the inner surface of the larger sphere is equal to and opposite that of the smaller sphere, the larger sphere's outer must be positively charged.