Magnetism

Question	Answer
Which poles attract and which repel?	Like poles repel and unlike poles attract, for example N and N or S and S repel but N and S attract.
What is a ferrous material?	A ferrous material contains iron, for example steel. Any ferrous material can be magnetised and demagnetised.
How is magnetism induced?	Magnetism is induced in a bar of ferrous material when a magnet is placed near it.
What is a line of force?	A line of force (also called a field line) of a magnetic field is a line along which a plotting compass points.
What does a magnetic field look like around a bar magnet?	Image: bar_magnet (image/jpg)
What do the magnetic field lines of a bar magnet look like?	The magnetic field lines of a bar magnet curve from the North pole of the bar magnet around to the South pole of the bar magnet.
How can an iron or steel bar be magnetised?	By repeatedly moving a pole of a bar magnet along the bar in one direction. And by withdrawing the bar from a long coil carrying direct current.
What is a 'hard' magnetic material?	A 'hard' magnetic material is a material harder to magnetise and demagnetise rather than a 'soft' magnetic material.
In magnetic terms what is the metal that is 'hard'?	Steel
In magnetic terms, what is the material that is 'soft'?	Iron
What are iron and steel used for?	Iron is used in an electromagnet and steel is used in a permanent magnet.

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	Created by harrilou24 about 10 years ago

	Copied by Steven Bentley about 7 years ago