Question

Two bodies A and B of definite shape are placed near each other. Electrostatic attraction is found between the bodies, then
A. Both bodies must be positively charged.
B. Both bodies must be negatively charged
C. Both bodies must be oppositely charged
D. Body A must be neutral.

Answer 1

When the charge on both the bodies are of similar nature, the two bodies will repel each other. When the charges on the two bodies are opposite in nature (meaning one positively charged and other negatively charged) then the two bodies will attract each other.

Complete answer:
With help of the Coulomb’s law of electrostatics, we understand that any two charged bodies in the universe will exert a force on each other. This force is called electrostatic force.
Unlike gravity, electrostatic force can be attractive as well as repulsive in nature. The nature of the force depends on the charge on the bodies.

When the charge on both the bodies are of similar nature (not necessarily equal), the two bodies will repel each other. This means that when either the bodies are positively charged or both the bodies are negatively charged, then they will repel each other.

On the other hand, when the charges on the two bodies are opposite nature (meaning one positively charged and other negatively charged), the two bodies will attract each other.
It is given that two bodies A and B are kept near each other. The electrostatic force between the two found to be attractive. Then this means that the two bodies must be oppositely charged.

Hence, the correct option is C.

Note: A body that does have a net charge on it is said to be neutral. Note that for an electrostatic force to come into play between two bodies, both the bodies must be charged. If anyone of the bodies is neutral then the bodies will not feel any electrostatic force.