Ans. ELECTROSTATIC INDUCTION
The process of charging a conductor without any contact with the charging body is known as electrostatic induction.
Method of Charging Bodies by Electrostatic Induction
Take two metal spheres A and B and place them on an insulating stand as shown in Fig.13.3 (a). Now bring a positively charged rod near sphere A as shown in Fig. 13.3(b). The rod will attract negative charge towards it and repel positive charge away from it. Negative charge will be developed on the left surface of the sphere A which is close to the rod. While positive charge will be developed on the right surface of the sphere B.
(d) (e) Fig/l 3.3: Charging two spheres by electrostatic induction.
Now separate the spheres by a small distance while the rod is still near the sphere A. The two spheres will be oppositely charged and attract each other as shown in Fig.13.3 (c). Remove the rod. The charges on spheres rearrange themselves as shown in Fig.13.3 (d). Now separate the spheres by a large distance.
In this process, an equal and opposite charge will be developed on each metal sphere. This is charging by electrostatic induction.