Quantization of electric charge means

The correct answer is Option (1) → The total charge of a body is always an integral multiple of the charge on an electron.

Quantisation of charge means that charge exists only in discrete packets: the charge on any body is a whole-number multiple of the basic charge e, the magnitude of the charge on an electron.

    \( q = \pm ne, \quad n = 1, 2, 3, \ldots \)
    \( e = 1.6\times10^{-19}\ \mathrm{C} \)

Why the other options are incorrect

• Option (2) The charge on the body is not discrete but continuous. — Incorrect. This is the opposite of quantisation. Charge is discrete, although at the large scale, where n is huge, it appears continuous.

• Option (3) The charge on a body is additive in nature. — Incorrect. This is a different property, additivity: the total charge is the algebraic sum of the individual charges.

• Option (4) The charge is invariant. — Incorrect. This is also a different property: the charge of a particle does not depend on its speed or the observer’s frame of reference.

NCERT (2026-27):
Quantisation of Charge – “Experimentally it is established that all free charges are integral multiples of a basic unit of charge denoted by \( e \). Thus charge \( q \) on a body is always given by

    \( \displaystyle q = ne \)

where \( n \) is any integer, positive or negative. This basic unit of charge is the charge that an electron or proton carries. … The fact that electric charge is always an integral multiple of \( e \) is termed as quantisation of charge.”