Physics Magnets

What are the four magnetic materials?

Iron, Steel, Nickel, Cobalt

How would you find out which materials are magnetic?

See if they are attracted to a magnet

What are some uses of magnets?

Compasses, recycling and fridge magnets

What is a magnetic field?

the area around a magnet in which the effect of magnetism is felt

What direction do the magnetic field lines go?

North to south

What does the proximity of the magnetic field lines tell you?

How strong the magnet is

How does a compass work?

A permanently magnetised needle is placed on a pivot so that it rotates freely in the horizontal plane. The Earth's magnetic field exerts a force on the compass needle, causing it to rotate until it comes to rest in the same direction as the magnetic field.

Where is the Earth’s magnetic field the strongest?

The poles

How do you magnetise something?

Stroke it with a magnet

How do you demagnetise a magnet

Drop it or heat it

Why does steel make a better magnet than iron

Steel holds its magnetism better

Why does iron make a better electromagnet than steel

Iron holds its magnetism for shorter time so the magnet isn’t permanent.

How can an electromagnet be turned on and off?

Break the circuit

How can you increase the strength of an electromagnet?

Increase the number of coils or increase the current