Magnetism and Electromagnetism
4 marks · EasyA physics teacher demonstrates induced magnetism using an iron nail and a bar magnet.
Describe what happens to the iron nail when it is placed next to the bar magnet and why.
State whether the induced magnetism in the iron nail is temporary or permanent. Give a reason for your answer.
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(a) The iron nail becomes magnetised (is attracted to the magnet) because magnetism is induced in it.
(b) The induced magnetism is temporary because iron is a magnetically soft material and loses its magnetism when removed from the field.
Common mistakes: Saying iron nail becomes permanently magnetised
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Describes that iron nail becomes magnetised or is attracted.
M1 (a) · 1 mark · Mentions induced magnetism as the cause.
B2 (b) · 2 marks · States induced magnetism is temporary with correct reason (iron is magnetically soft). 1 mark for temporary, 1 mark for correct reason; both for 2 marks.
Worked solution
a) When the iron nail is placed close to the bar magnet, it becomes magnetised and is attracted to the magnet because magnetism is induced in the nail.
b) The induced magnetism is temporary because iron is a magnetically soft material and loses its magnetism when the magnet is removed.