Question

Quantisation of charge implies
(a). Charge does not exist
(b). Charge exists on particles
(c). There is minimum permissible magnitude of charge
(d). Charge can’t be created

Answer 1

- Hint: A charged body contains either protons or electrons. That determines their charge.

Complete step-by-step solution -

According to the concept of quantisation of charge, electric charge can exist only as an integral multiple of charge of an electron. The charge of an electron is considered as the basis of any charge system. That is \[q=\pm ne\], where n is an integer and e is the charge of an electron. The possible electric charge values are \[\text{q= }\!\!\pm\!\!\text{ 1e, }\!\!\pm\!\!\text{ 2e, }\pm \text{3e, }\pm \text{4e,}.....\]etc. It is not possible to have a charge less than the charge of an electron to any system. i.e. \[1.6\times {{10}^{-19}}\text{ C}\] is the minimum charge of any system.
So that the option (c) is correct. There is a minimum permissible magnitude of charge.

ADDITIONAL INFORMATION:

Quantum of charge implies the minimum amount of charge, and all quantities of charge greater than the exact integer multiples of that quantum. We have a detailed theory of quarks. Each charge is composed of down and up quarks. Down quarks have \[\pm \dfrac{1}{3}e\]charge and up quarks have \[\pm \dfrac{2}{3}e\] charge. A proton contains two up quarks and one down quark. Thus, it has a total charge of +1 while two down and one up quark give a neutron of net charge 0. Quarks always combine in several ways to keep the charges as the integral multiples of the electron.

Note: The smallest amount of charge that has ever been discovered is the charge of an electron or the charge of a proton. Both are the same but opposite charges. Quantisation of charge doesn’t mean the conservation of energy. Thus, no need to focus on the other options.