I → Intensity of magnetizationH → Magnetic intensity(A) (a) is steel,…

The correct answer is Option (2) → (A), (B) and (D)

On a hysteresis loop (I against H), the height where the loop cuts the I-axis is the retentivity (magnetisation left when H is brought to zero), and the distance where it cuts the H-axis is the coercivity (reverse field needed to remove that magnetisation).

From the figure: loop (a) is wide, so it has a large coercivity; loop (b) is tall and very narrow, so it has a small coercivity and cuts the I-axis higher than (a).

(A) (a) is steel, (b) is soft iron — Correct. Steel needs a large reverse field to demagnetise (wide loop); soft iron needs very little (narrow loop).

(B) retentivity of (b) > (a) — Correct. Loop (b) cuts the I-axis higher than loop (a); soft iron has a slightly greater retentivity than steel.

(C) (a) is used to make temporary magnets — Incorrect. Steel, with its high coercivity, keeps its magnetism against stray fields, so it is used for permanent magnets. Temporary magnets (electromagnet cores) need soft iron.

(D) (b) can be easily demagnetised — Correct. Its coercivity is very small, so a small reverse field removes its magnetisation.

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 – “… The hysteresis curve (Fig. 5.14) allows us to select suitable materials for permanent magnets. The material should have high retentivity so that the magnet is strong and high coercivity so that the magnetisation is not erased by stray magnetic fields, temperature fluctuations or minor mechanical damage. … 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.”