Understanding Magnets and Electromagnets

Which of the following is NOT a magnetic material?

• Iron

• Cobalt

• Nickel

• Aluminium

What is the name of the force that magnets exert on certain materials?

• Gravitational force

• Magnetic force

• Frictional force

• Electrostatic force

If a bar magnet is cut in half, what happens to the two pieces?

• They become unmagnetised

• Each piece becomes a smaller magnet with a north and south pole

• They only have a north pole

• They only have a south pole

What type of magnet is used in a scrapyard crane?

• Bar magnet

• Horseshoe magnet

• Electromagnet

• Temporary magnet

Which of the following statements is TRUE about an electromagnet?

• It can be turned on and off

• It is always magnetic

• It is weaker than a permanent magnet

• It does not need electricity to work

What happens to the strength of an electromagnet if you increase the current flowing through the wire?

• It gets weaker

• It stays the same

• It gets stronger

• It repels all metals

Which part of an electromagnet increases its strength the most?

• Using a wooden core

• Using an iron core

• Using a plastic core

• Using a rubber core

What is the direction of a magnetic field around a bar magnet?

• From south to north

• From north to south

• In a straight line

• In a circular motion

Which device uses electromagnets?

• A wooden ruler

• A battery

• A doorbell

• A paperclip

If the current in an electromagnet is stopped, what happens?

• The magnet becomes stronger

• The magnetism disappears

• The magnet attracts more objects

• The magnet repels metal