Name: Electric and Gravitational Forces
Uploaded: 2019-07-19
Duration: 3 min 11 s
Description: Do you know the difference and similarities between the gravitational force and electrostatic force? Watch this video to explore it. Don't miss it.

Question

Define electrostatic induction. Briefly explain how an insulated metal sphere can be positively charged by induction.

Accepted Answer

It is the phenomenon of temporary electrification, of a conductor, when a charged body is placed near it, opposite charge appears it its closer end and similar charge appears at its father end.

(a) Hold the two metal spheres on insulating stands and place them side by side in contact.

(b) Bring a positively charged glass rod near the left sphere. The free electrons of the spheres get attracted towards the glass rod. The left surface of the left sphere develops an excess of negative charge while the right side of the right sphere develops an excess of positive charge. However, all the electrons of the spheres do not collect at the left face. As the negative charge begins to build up at the left face, it starts repelling the new incoming electrons. Soon an equilibrium is by established under the action of force of attraction of the rod and the force of repulsion due to the accumulated electrons.

(c) Holding the glass rod near the left sphere, separate the two spheres by a small distance. The two spheres now have opposite charges.

(d) Remove the glass rod. The charges on the spheres get redistributed. Their positive and negative charges face each other. The two spheres attract each other.

(e) When the two spheres are separated quite apart, the charges on them get uniformly distributed.

Thus, the two metal spheres get charged by a process called charging by induction.

Define electrostatic induction. Briefly explain how an insulated metal sphere can be positively charged by induction.

Important Questions on Electric Charges and Field

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