Question

The minimum charge on an object is:
(A) 1 coulomb
(B) 1 stat Coulomb
(C) $1.6 \times 10^{-20} $ Coulomb
(D) $1.6 \times 10^{-19} $ Coulomb

Answer 1

Hint: Electric charge on an object is the given or taken from it in the form of electron transfer. A body is said to possess some charge when it lacks or gains some electrons. The charge transfer process is quantized in nature.

Complete answer:
Any material is made up of atoms. Atoms are made up of electrons and nuclei. This means that atoms are charged in nature. We can charge a body in various ways. One of the ways to charge a body is to rub it against some other material that causes one of the materials to gain some electrons and the other one to lose the same amount of electrons. Basically, charging is the process of transfer of electrons. For a body to possess some charge, the body has to either lose some of its valence electrons or it should gain some valence electrons from another body. Therefore, the total amount of charge that any body possesses depends on the number of electrons transferred. No further division of charge can be done. The fundamental quantity of charge that gets transferred is the amount of charge that an electron possesses.
Therefore the amount of charge that an electron possesses is $1.6 \times 10^{-19}$ C. Therefore the minimum amount of charge that any object can possess is this.

Therefore the correct option is (C).

Note:
Further division of charge from the basic unit cannot be done. Sometimes a metal is also charged by connecting it with an external supply and then connecting to the ground so that the extra charge that the metal possesses. This arrangement is used in capacitors.