Electrostatic Induction – In fig. 15.2, PQ is a metallic body which is mounted on an insulated stand. If a negatively charged ebonite rod is brought near its end P, tests will reveal the presence of negative charge at the end Q and positive charge at the end P. when the ebonite rod is removed away, the charge on PQ also vanishes showing that the charge on PQ appears only in the presence of the charged ebonite rod.
If in the presence of a charged body, an insulated conductor has like charges at one end unlike charges at the other end then this is called the electrostatic.In this phenomenon all charges remain static that is why it is known as electrostatic.
Negative Charges Present
This phenomenon can be explained in terms of free electrons. The negative charges present on the ebonite rod repel the free electrons to the electrons at the end Q, in this way the end Q gets negatively charged and a deficiency of electrons occurs at the end P due to which it shows positive charge.
The quantity of negative charge at Q is equal to the quantity of positive charge appearing at P. that is why when the negative charge on an ebonite rod is removed, the repelling force acting on free electrons vanishes and free electrons spread uniformly on the whole of the conductor.