Which of the following statement are correct?
A. Magnetisation of a sample is equal to its magnetic moment per unit volume.
B. For measuring currents, the galvanometer has to be connected in parallel in the circuit.
C. In an ideal toroid the coils are circular.
D. In larger the number of field lines crossing per unit area, the stronger is the magnitude of magnetic field.
E. The currents flowing in the same direction attract each other.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, C, D and E only
(A) Magnetisation of a sample is equal to its magnetic moment per unit volume — Correct. This is the definition of magnetisation, \( M = m_{\mathrm{net}}/V \).
(B) For measuring currents, the galvanometer has to be connected in parallel in the circuit — Incorrect. A current meter must carry the current to be measured, so it is connected in series; a parallel connection is used for a voltmeter or for the shunt.
(C) In an ideal toroid the coils are circular — Correct. A toroid is a hollow circular ring on which the turns of wire are closely wound.
(D) In larger the number of field lines crossing per unit area, the stronger is the magnitude of magnetic field — Correct. The density of field lines represents the strength of the field.
(E) The currents flowing in the same direction attract each other — Correct. Parallel currents attract and anti-parallel currents repel.
Note: Statements (A), (B), (D) and (E) of this question are from the latest textbook (2026-27). Statement (C), that in an ideal toroid the coils are circular, is printed only in the pre-rationalised textbook (2022-23). It was removed from the latest book, and it also appears to be out of the CUET 2026 syllabus.
NCERT (2026-27):
Magnetisation and Magnetic Intensity – “… We define magnetisation M of a sample to be equal to its net magnetic moment per unit volume:
\( \displaystyle \mathbf{M} = \frac{\mathbf{m}_{net}}{V} \qquad (5.7) \)”
The Moving Coil Galvanometer – “… (ii) For measuring currents, the galvanometer has to be connected in series, and as it has a large resistance, this will change the value of the current in the circuit.”
The Magnetic Field Lines – “… (iii) The larger the number of field lines crossing per unit area, the stronger is the magnitude of the magnetic field B.”
Force Between Two Parallel Currents, the Ampere – “… We have seen from above that currents flowing in the same direction attract each other.”
NCERT (Pre-rationalised edition, 2022-23):
The Toroid – “… In an ideal toroid the coils are circular.”