Match List-I with List-II.
| List-I | List-II |
|---|---|
| (A) A paramagnetic sample is cooled in a fixed external magnetic field | (I) Magnetisation varies randomly from domain to domain |
| (B) All the atomic dipoles of a paramagnetic sample are aligned with the field | (II) Magnetisation increases |
| (C) A ferromagnetic sample is heated to a high enough temperature | (III) The sample behaves as a paramagnet |
| (D) An unmagnetised ferromagnetic sample is kept with no external field | (IV) Magnetisation reaches its saturation value |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(IV), (C)-(III), (D)-(I)
(A) A paramagnetic sample is cooled in a fixed external magnetic field — This matches (II) magnetisation increases. At a lower temperature the random thermal motion is weaker, so more atomic dipoles line up with the field.
(B) All the atomic dipoles of a paramagnetic sample are aligned with the field — This matches (IV) magnetisation reaches its saturation value. When every dipole already points along the field, the magnetisation cannot grow any further.
(C) A ferromagnetic sample is heated to a high enough temperature — This matches (III) the sample behaves as a paramagnet. Heating breaks up the domain structure, and the strong magnetic property is lost.
(D) An unmagnetised ferromagnetic sample is kept with no external field — This matches (I) magnetisation varies randomly from domain to domain. Each domain is magnetised, but the domains point in different directions, so there is no bulk magnetisation.
NCERT (2026-27):
Paramagnetism – “… As the field is increased or the temperature is lowered, the magnetisation increases until it reaches the saturation value at which point all the dipoles are perfectly aligned with the field.”
Ferromagnetism – “The ferromagnetic property depends on temperature. At high enough temperature, a ferromagnet becomes a paramagnet. The domain structure disintegrates with temperature. …”
Ferromagnetism – “… In the first instant, the magnetisation varies randomly from domain to domain and there is no bulk magnetisation. …”