IGCSE Electromagnetism Flashcards
Describe the forces between like and unlike poles of a magnet.
- Opposite Poles attract
- Like Poles repel
Magnets are also able to attract some objects made of magnetic materials such as iron, steel, nickel and cobalt.
What is the difference between magnetically Hard and Soft Materials?
- Metallically hard materials e.g. steel retain their magnetism once magnetised.
- Magnetically soft materials e.g. iron lose their magnetism easily and are only useful as temporary magnets.
What is meant by a ferrous material?
It is a material such as steel that contains Iron. Ferrous materials can be magnetised and demagnetised.
What is induced magnetism?
Magnetism can be induced in a bar of ferrous material when a magnet is placed near it.
When the magnet is removed, the magnetism is lost.
(The material will be attracted to the permanent magnet so the nearest pole of the bar magnet will induce the opposite pole in the nearest part of the object).
What is an electromagnet?
An electromagnet can made from a coil of insulated wire.
To increase its strength:
• wrap the coil around a soft iron core
• add more turns to the coil
• increase the current flowing through the coil.
