(a) Explain the meaning of the statement ‘electric charge of a body is quantised’.
(b) Why can one ignore quantisation of electric charge when dealing with macroscopic i.e., large scale charges?
Answers
(a) Quantization is one of the three basic properties of electric charge. It means that every charge is an integral multiple of e, i.e., ne, n =-2, -1, 0, 1, 2…The addition of charges, subtraction of charges, being an integer always gives integer result. Thus a charge can always be incremented or decremented in terms of e.
(b) Macroscopic charges have very large number of electrons. The quantization here can be taken as a continuous phenomenon, analogous to closely spaced dots resembling to line from a distance.
Explanation:
a) Electric charge of a body is quantized. This means that only integral (1, 2, …., n) number of electrons can be transferred from one body to the other. Charges are not transferred in fraction. Hence, a body possesses total charge only in integral multiples of electric charge.
(b) In macroscopic or large scale charges, the charges used are huge as compared to the magnitude of electric charge. Hence, quantization of electric charge is of no use on macroscopic scale. Therefore, it is ignored and it is considered that electric charge is continuous .