Which of the following statements are correct?(A) Permeability of sof…

The correct answer is Option (3) → (B) and (C) only

The magnetic permeability \( \mu \) and the susceptibility \( \chi \) of a material are related by \( \mu_r = 1 + \chi \), so both are large for a material that is easily magnetised. Soft iron is such a material, which is why it is used for the cores of electromagnets and transformers.

(A) Permeability of soft iron < permeability of steel — Incorrect. Soft iron has the higher permeability, so this is the wrong way round.

(B) Susceptibility of soft iron > susceptibility of steel — Correct. Since \( \chi = \mu_r - 1 \), the higher permeability of soft iron means a higher susceptibility.

(C) Retentivity of soft iron > Retentivity of steel — Correct. The textbook states that steel has a slightly smaller retentivity than soft iron; steel is preferred for permanent magnets only because its coercivity is far larger.

(D) Coercivity of soft iron > coercivity of steel — Incorrect. Soft iron has a very small coercivity; its magnetisation is easily reversed, whereas steel has a large coercivity and holds its magnetisation, which is why steel is chosen for permanent magnets.

Note: This question is from the pre-rationalised NCERT book (2022-23). The topic was removed from the latest NCERT book (2026-27), and it also appears to be out of the CUET 2026 syllabus.

NCERT (Pre-rationalised edition, 2022-23):
Permanent Magnets and Electromagnets – “… Steel is one-favoured choice. It has a slightly smaller retentivity than soft iron but this is outweighed by the much smaller coercivity of soft iron. … Core of electromagnets are made of ferromagnetic materials which have high permeability and low retentivity. Soft iron is a suitable material for electromagnets.”