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Why is soft iron used as the core of an electromagnet?
AIt retains magnetism after current is switched off
BIt conducts current better than copper
CIt increases the resistance of the coil
DIt is easy to magnetise and easy to demagnetise
Answer & Solution
Correct answer: D. It is easy to magnetise and easy to demagnetise
1. An electromagnet needs to switch its magnetism on and off cleanly.
2. Soft iron magnetises strongly when current flows in the surrounding coil.
3. It also loses its magnetism quickly once the current is switched off.
4. This makes it ideal for devices like relays, doorbells and motors.
5. Steel would retain magnetism, making it a permanent magnet instead.
6. So soft iron is used because it is easy to magnetise and demagnetise.
_Source: NCERT Class 10 Science Ch 13 'Magnetic Effects of Electric Current' (learncbse.in extract)_
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