Physics Form 5: Chapter 3 - Electromagnet

• An electromagnet is a coil which can produce a magnetic field when a current passes through it and losses all its magnetism when the current is switched off.
• Soft-iron is suitable to use as a core because it can be magnetized and demagnetized easily and also soft iron can concentrate the magnetic field.
• The steel core magnet remains magnetised when the current is switched off. Therefore, steel is not suitable as the core of electromagnets. Anyway, steel is suitable to use as a bar magnet.

Click on the diagram below to play!

The strength of a electromagnet can be increased by:

• increasing the current flowing through the coil
• increasing the number or turns.
• the use of a soft iron core