Magnetism

What poles attract?

S and N.

What poles repel?

S and S, N and N.

Name a magnetic material.

Iron, steel, cobalt, nickel, and some rare earth metals like neodymium.

What direction do magnetic field lines go?

North to south.

What is induced magnetism?

When a non-magnetic object becomes a magnet when attached to one.

When will a wire have a magnetic field round it?

When it has a current running through it.

What is a permanent magnet?

An object that always has a magnetic field around it.

What is a temporary magnet?

An object that only has induced magnetism from actual magnetic objects.

How do you increase the strength of an electromagnet?

Add more coils or increase the current.

What is the motor effect?

When any wire carrying a current can experience a force near a magnetic field.

What do transformers do?

They change the voltage of an electrical supply.

What is a transformer made up of?

Two coils wound onto an iron core.

Why is the power supplied to the primary coil and the power supplied away from the secondary coil equal?

Energy can’t be created or destroyed.

What do pylons do?

They transport energy to factories, homes, shops and offices across the country through extremely long overhead copper wires.

How do you prevent energy being wasted in wires?

By decreasing the current so less energy is wasted through heating.

What is a step-up transformer?

A transformer that increases voltage and decreases current simultaneously.

What is a step-down transformer?

A transformer that lowers voltage and increases current simultaneously.