Identify the correct statements in the context of electric charges:
(A) The charges can be added up like real numbers.
(B) Total charge of an isolated system is always conserved.
(C) Conservation of charges cannot be established experimentally.
(D) At the macroscopic level, the quantisation of charges can be ignored.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A), (B) and (D) only
The basic properties of electric charge are additivity, conservation and quantisation.
(A) The charges can be added up like real numbers. — Correct. Charge is a scalar, so the total charge of a system is the algebraic sum of the individual charges, signs included.
(B) Total charge of an isolated system is always conserved. — Correct. Charges can be transferred or created in equal and opposite pairs, but the net charge of an isolated system never changes.
(C) Conservation of charges cannot be established experimentally. — Incorrect. Charge conservation is an experimentally established law; every observed process, including pair production and nuclear reactions, obeys it.
(D) At the macroscopic level, the quantisation of charges can be ignored. — Correct. Everyday charges (of the order of \( \mu\mathrm{C} \)) contain about \( 10^{13} \) electronic charges, so the steps of size e are far too small to notice and charge can be treated as continuous.
NCERT (2026-27):
Additivity of Charges – “… If a system contains two point charges q1 and q2, the total charge of the system is obtained simply by adding algebraically q1 and q2, i.e., charges add up like real numbers or they are scalars like the mass of a body.”
Conservation of Charge – “… Within an isolated system consisting of many charged bodies, due to interactions among the bodies, charges may get redistributed but it is found that the total charge of the isolated system is always conserved. Conservation of charge has been established experimentally.”
Quantisation of Charge – “… Thus, at the macroscopic level, the quantisation of charge has no practical consequence and can be ignored.”