CAX IGCSE PHYSICS magnetism

Which statement about a magnet is correct?

• A magnet attracts a gold rod.

• A magnet does not attract a plastic rod.

• A magnet never repels another magnet.

• A magnet sometimes repels an unmagnetised nickel rod.

Which statement about magnetism is correct?

• An unmagnetised iron bar becomes magnetised when it is placed near a magnet.

• An unmagnetised steel bar can be magnetised by passing a current through it.

• The direction of magnetic field lines is from an S-pole to an N-pole.

• The N-poles of two magnets attract each other.

In which pair are both materials magnetic?

• aluminium and copper

• copper and iron

• iron and steel

• steel and aluminium

The diagram shows the magnetic field around two bar magnets.

Which diagram shows the poles of the magnets?

• 
• 
• 
• 

The diagram shows apparatus that can be used to make a magnet.

Which metal and which power supply are used to make a permanent magnet?

• metal = iron; power supply = 6 V a.c.

• metal = iron; power supply = 6 V d.c.

• metal = steel; power supply = 6 V a.c.

• metal = steel; power supply = 6 V d.c.

A wire perpendicular to the page carries an electric current in a direction out of the page. There are four compasses near the wire.

Which compass shows the direction of the magnetic field caused by the current?

• A

• B

• C

• D

An electromagnet with a soft-iron core is connected to a battery and an open switch. The soft-iron core is just above some small soft-iron nails.

The switch is now closed, left closed for a few seconds, and then opened.

What do the soft-iron nails do as the switch is closed, and what do they do when the switch is then opened?

• as switch is closed - nails jump up; as switch is opened - nails fall down

• as switch is closed - nails jump up; as switch is opened - nails stay up

• as switch is closed - nails stay down; as switch is opened - nails jump up

• as switch is closed - nails stay down; as switch is opened - nails stay down

Which action will demagnetise a magnetised piece of steel?

• Cool it in a freezer for several hours.

• Hit it repeatedly with a hammer.

• Put it in a coil carrying a direct current (d.c.).

• Put it near an unmagnetised piece of iron.

Which procedure may be used to demagnetise a steel bar?

• cooling it in a freezer for several hours

• earthing it with a copper wire for several seconds

• removing it slowly from a coil carrying an alternating current (a.c.)

• rubbing it in one direction with a woolen cloth

Which statement about a permanent bar magnet is correct?

• It is made from a soft magnetic material.

• It repels a non-magnetic material.

• Its field lines cross each other where the magnetic field is strong.

• Its N-pole repels the N-pole of another magnet.