Magnetism

5 marks · Normal

An iron nail and a steel nail are both placed in contact with the end of a bar magnet.

(a)

State what will happen to each nail while the bar magnet is present.

[2 marks]

(b)

Describe what happens to the magnetism in each nail after the bar magnet is removed.

[2 marks]

(c)

Explain the difference in behaviour between the iron nail and the steel nail using the ideas of magnetically soft and hard materials.

[1 mark]

Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.

Show answer

(a) Both nails become temporary magnets when in contact with the magnet. · must show Both nails are attracted, Both become magnetised

(b) The iron nail loses most or all of its magnetism quickly, while the steel nail keeps its magnetism longer. · must show Iron nail loses magnetism, Steel nail stays magnetised

(c) Iron is magnetically soft, so it loses magnetism easily; steel is magnetically hard, so it keeps magnetism. · must show Iron is soft, Steel is hard

Common mistakes: Saying both nails stay magnetised forever; Confusing which is soft and which is hard

Show mark scheme and worked solution

Marking points

B1 (a) · 1 mark · States both nails become magnetised (induced magnets) in contact with magnet.

B2 (a) · 1 mark · States both nails are attracted to the bar magnet.

B1 (b) · 1 mark · Correctly describes that steel nail stays magnetised and iron loses magnetism.

B2 (b) · 1 mark · Specifies loss of magnetism is quick for iron, slow or none for steel.

B1 (c) · 1 mark · Explains difference using terms 'magnetically soft' (iron) and 'magnetically hard' (steel).

Worked solution

(a) Both nails become magnetised due to the bar magnet's field, so both are attracted to it.

(b) Once the magnet is removed, the iron nail (magnetically soft) quickly loses its magnetism, while the steel nail (magnetically hard) keeps most of its magnetism.

(c) This difference is because iron is magnetically soft, losing magnetism easily, but steel is magnetically hard and retains its magnetism longer.