Match List - I with List - II.List - IList - II(A) Minimum magnetic m…

The correct answer is Option (4) → (A)-(III), (B)-(I), (C)-(IV), (D)-(II)

The four items are basic terms of magnetism and matter: the magnetic moment of an orbiting electron, and how materials respond to an applied field.

(A) Minimum magnetic moment associated with orbital motion of electron in 1st orbit is — this matches (III) Bohr Magneton. An electron in the first Bohr orbit (\( n = 1 \)) has the least orbital magnetic moment, called the Bohr magneton.

    \( \displaystyle \mu_{B} = \frac{e h}{4\pi m_e} = 9.27\times10^{-24}\,\mathrm{A\,m^{2}} \)

(B) Paramagnetic materials have relative permeability — this matches (I) greater than one. A paramagnetic material is weakly magnetised along the applied field, so its susceptibility is small and positive and \( \mu_r = 1 + \chi \) is slightly greater than one.

(C) Magnetic moment per unit volume of the material is called — this matches (IV) Intensity of magnetisation. The net magnetic moment per unit volume is the magnetisation \( M \) (also called the intensity of magnetisation), measured in \( \mathrm{A\,m^{-1}} \).

(D) Perfect diamagnetism of superconductors — this matches (II) Meissner's effect. A superconductor cooled below its critical temperature expels the magnetic field from its interior completely (\( \chi = -1 \)); this expulsion is the Meissner effect.

Note: Items (B), (C) and (D) of this question are from the latest textbook (2026-27). Item (A), the Bohr magneton, 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 – “… χ is small and positive for materials, which are called paramagnetic.”

Magnetisation and Magnetic Intensity – “… where μ_r = 1 + χ, is a dimensionless quantity called the relative magnetic permeability of the substance.”

Magnetisation and Magnetic Intensity – “… We define magnetisation M of a sample to be equal to its net magnetic moment per unit volume:

    \( \displaystyle \mathbf{M} = \frac{\mathbf{m}_{net}}{V} \qquad (5.7) \)”

Diamagnetism – “… The phenomenon of perfect diamagnetism in superconductors is called the Meissner effect, after the name of its discoverer.”

NCERT (Pre-rationalised edition, 2022-23):
The Magnetic Dipole Moment of a Revolving Electron – “… Take the value n = 1, we have from Eq. (4.34) that,

    \( \displaystyle (\mu_l)_{min} = \frac{e h}{4\pi m_e} = 9.27 \times 10^{-24}\ \mathrm{A\,m^2} \qquad (4.37) \)

where the subscript ‘min’ stands for minimum. This value is called the Bohr magneton.”