Magnets & Electromagnets topic test Yr8

Where is the magnetic field the strongest?

• The magnetic field is strongest further away from the magnet

• The magnetic field is strongest closest to magnet

Why is an electromagnet classified as a temporary magnet?

• It is only a magnet when the current is flowing

• It is only a magnet when the force is strong

• It is only a magnet when in Kevin's class

• It is only a magnet if paper clips can be picked up

When a current is running through a coil of wire with an iron core, what is created around the wire that is carrying the current?

• An electric force

• A magnetic field

• An electric field

• A magnetic compass

If a magnet is broken in half what two things will occur?

• the north pole and south pole are separated

• new north and south poles are created

• nothing

• Kevin will be angry

A compass needle points north because of Earth's magnetic field unless

• it is close to a wire with a current

• it is close to any wire

• it is close to a battery

• it is close to the window

The electromagnetic forces from a current carrying wire are strong enough to move the compass needle. The forces can be made stronger by

• making the wire shorter

• making the wire longer

• making the wire into loops

• changing the colour of the wire

Refrigerator magnets and bar magnets are what type of magnet?

• electromagnet

• electronic

• permanent

• useful

What THREE ways are electromagnets different from permanent magnets?

• they can be turned off and on

• they can increase in strength by increasing the current in the wire

• they are smaller in size

• they can change which is the north and south pole

Tags

NGSS.MS-PS2-3

Electromagnets are useful in industry such as a junk yard because they

• have strong north and south poles

• are easy to lift

• can be turned off and on

• use renewable energy

Permanent Magnets and Electromagnets are similar in which TWO ways?

• it can be turned off and on

• they both have a north and south pole

• they are surrounded by a magnetic field

• they have electric current in them