THE TRANSFORMER
3 marks · EasyThe diagram below shows a basic transformer.
State the name of the part labelled as 'soft iron core'.
Explain why a soft iron core is used in a transformer.
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.
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(a) soft iron core
(b) It easily allows magnetic fields to pass through, linking the coils; it increases efficiency by providing a path for the changing magnetic field.
Must show: soft iron core labelled
Common mistakes: Saying 'iron' but not 'soft iron'; Explaining it is needed because it is magnetic only (not mentioning magnetic linkage/field)
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Marking points
B1 (a) · 1 mark · States 'soft iron core'.
M1 (b) · 1 mark · Mentions use is to link the magnetic field between coils or acts as a magnetic circuit.
A1 (b) · 1 mark · States that it increases efficiency/reduces energy losses.
Worked solution
a) The labelled part is the 'soft iron core'.
b) The soft iron core links the primary and secondary coils with a magnetic field. It provides a path for the magnetic field, increasing transformer efficiency by reducing energy loss.