basics - magnets

What are the poles of a magnet?

Its two ends, called the North Pole and South Pole

What happens when 2 magnets are brought close together?

They exert a force on each other

What do two like poles do?

They repel each other

What do two unlike poles do?

They attract each other

what are attraction and repulsion between 2 magnetic poles examples of?

A non contact force

What is a permanent magnet?

material that produces its own magnetic field

What is an induced magnet?

A material that becomes a magnet when it is placed in a magnetic field

What is the magnets magnetic field

How does the Bell RP work.

The current goes through the electromagnet.
The iron armature gets attracted to the electromagnet
This causes the striker to hit the bells gong
The circuit breaks and springs back and remakes the circuit.

What happens when you increase the current on the magnetic field around a wire?

The strength of the magnetic field gets stronger.

What metals are magnetic

iron, nickel, cobalt

non

magnetic metals

examples of permanent magnets

Alnico

examples of induced magnets

nails, whiteboards, fridges, paperclips

what are domains

domains are regions that behave like tiny magnets in magnetisable materials

what happens when the domains are not aligned

The material is not magnetised

What happens when the domains are aligned

The material is magnetised

How do you align domains

by stroking the material with magnet

How do you jumble up the domains

By heating of banging the object

How does a compass show the magnetic field around a magnet

The compass needle points in the direction of the Earth's magnetic field, or the magnetic field of a magnet.

What is an electromagnet?

A coil with and iron core

How does an electromagnet work?

A wire carrying a current is wrapped around a piece of iron. When the iron is surrounded by the electric field, it creates a magnetic field and the iron becomes magnetised.

Why is an electromagnet stronger?

The iron is already magnetic so the iron becomes induced making the magnetic field stronger.

Uses of electromagnets

Electric bells, Tape recorders, Motors and generators

What happens if you increase the number of turns on the coil of an electromagnet?

The current increases