GCEPhysicsElectricity and Magnetism2020

Which of the following best explains why a soft iron core is used in a transformer instead of a steel core?

ASoft iron has higher electrical conductivity than steel.
BSoft iron can be magnetised and demagnetised more easily, reducing energy losses due to hysteresis.CORRECT
CSoft iron has a higher melting point, making it safer at high temperatures.
DSoft iron produces a stronger permanent magnetic field than steel.
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Why the answer is B, and why the others tempt you.
A transformer core undergoes repeated magnetisation and demagnetisation with each cycle of the alternating current. Soft iron has a narrow hysteresis loop, meaning it magnetises and demagnetises easily with minimal energy lost as heat (hysteresis loss). Steel has a wide hysteresis loop and retains magnetism (making it suitable for permanent magnets), which would cause excessive energy losses in a transformer.
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