Magnets and Electromagnets

What is magnetism?

A force produced by magnets that can attract or repel materials.

What is a magnet?

An object that creates a magnetic field.

What are the two poles of a magnet?

North pole and south pole.

What happens when opposite magnetic poles meet?

They attract each other.

What happens when like magnetic poles meet?

They repel each other.

What materials are magnetic?

Iron, nickel and cobalt.

What is a magnetic field?

The area around a magnet where magnetic forces act.

How can magnetic fields be shown?

Using iron filings or field lines.

Where is the magnetic field strongest around a magnet?

At the poles.

What is a permanent magnet?

A magnet that keeps its magnetism.

What is a temporary magnet?

A material that acts as a magnet only in a magnetic field.

What is electromagnetism?

Magnetism produced by an electric current.

What is an electromagnet?

A magnet created when electric current flows through a coil of wire.

Why are electromagnets useful?

They can be switched on and off.

How can the strength of an electromagnet be increased?

Increase current, add more coils or use an iron core.

What is a solenoid?

A coil of wire used to create a magnetic field.

What happens when current flows through a wire?

A magnetic field forms around it.

How can the direction of a magnetic field around a wire be found?

Using the right-hand grip rule.

What is the right-hand grip rule?

A method for finding magnetic field direction around a current-carrying wire.

What is induced magnetism?

When a material becomes magnetic in a magnetic field.

What is the Earth’s magnetic field?

A magnetic field surrounding Earth acting like a giant magnet.

Why does a compass work?

Its needle aligns with Earth’s magnetic field.

What is a compass used for?

Finding direction.

What is magnetic repulsion?

When like poles push apart.

What is magnetic attraction?

When opposite poles pull together.

What is an electromagnet commonly used for?

Scrapyard cranes, doorbells and electric motors.

Why are electromagnets used in scrapyards?

They can lift and release metal objects easily.

What is an electric motor?

A device converting electrical energy into movement.

How do magnets help electric motors work?

Magnetic forces cause rotation.

What is a relay in electronics?

A switch operated by an electromagnet.

Why are relays useful?

They allow low currents to control larger currents safely.

What is magnetic shielding?

Reducing the effects of magnetic fields.

What is demagnetisation?

The removal of magnetism from a material.

How can a magnet be demagnetised?

Heating, hammering or using alternating current.

What is magnetic induction?

Creating magnetism in a material without direct contact.

What happens when iron filings are placed near a magnet?

They align with the magnetic field.

What is a bar magnet?

A rectangular permanent magnet with north and south poles.

What is a horseshoe magnet?

A U-shaped magnet with strong magnetic force between poles.

What is a magnetic material?

A material attracted to magnets.

Why is steel used in permanent magnets?

It stays magnetised easily.

Why is iron used in electromagnets?

It magnetises and demagnetises quickly.

What is current in electricity?

The flow of electric charge.

How does increasing current affect an electromagnet?

It makes the magnetic field stronger.

What happens if more wire coils are added to an electromagnet?

The magnetic field becomes stronger.

What is the purpose of an iron core in an electromagnet?

It strengthens the magnetic field.

What is magnetisation?

The process of becoming magnetic.

Why are magnetic fields invisible?

They are forces that cannot be directly seen.

How are magnetic field lines drawn?

From north pole to south pole.

What is renewable energy technology that uses magnets?

Wind turbines and generators.

What is a generator?

A device converting movement into electrical energy.

How are magnets important in everyday life?

They are used in speakers, motors, phones and medical equipment.

Why are electromagnets more useful than permanent magnets in some situations?

Their strength and magnetism can be controlled.