15 Magnetism 2022 J&N

Point X is near to a bar magnet. Which arrow indicates the direction of the magnetic field of the bar magnet at point X?

• →

• ↑

• ↗

• ↘

The three diagrams each show two magnets.

In which diagrams do the two magnets attract each other?

• 1 only

• 1 and 3

• 2 only

• 2 and 3

The diagram shows the magnetic fields around three objects, P, Q and R, placed close to each other.

Which row shows the nature of each of the objects?

• P: permanent magnet (N S),

  Q: copper rod,

  R: permanent magnet (N S)

• P: permanent magnet (N S),

  Q: copper rod,

  R: permanent magnet (S N)

• P: permanent magnet (N S),

  Q: iron rod,

  R: permanent magnet (N S)

• P: permanent magnet (N S),

  Q: iron rod,

  R: permanent magnet (S N)

A student attempts to make a permanent magnet by hammering metal bars of the same size in the same magnetic field.

In which case is the strongest permanent magnet produced?

A student places object X on a balance. The student first brings magnet Y and then magnet Z close to object X and observes the readings on the balance. The distance between Y and X is the same as the distance between Z and X.

The diagram shows the results of the experiment.

Which statement explains the results?

• Object X is an iron block and magnet Y is stronger than magnet Z.

• Object X is an iron block and magnet Y is weaker than magnet Z.

• Object X is a permanent magnet and magnet Y is stronger than magnet Z.

• Object X is a permanent magnet and magnet Y is weaker than magnet Z.

Which statement is not a method for magnetising an iron bar?

• Place the bar next to a magnet and hammer the bar.

• Place the bar inside a solenoid. Switch on an alternating current (a.c.) in the coil and gradually reduce the current.

• Place the bar inside a solenoid. Switch on a direct current (d.c.) in the coil and gradually reduce the current.

• Stroke the bar repeatedly with a magnet.

Two magnets X and Y are placed end to end on a bench. The diagram shows the magnetic field pattern between the poles of the magnets.

Which row shows the direction of the forces exerted on X and Y by the magnetic field?

• → →

• ← →

• → ←

• ← ←

A student is to demagnetise a bar magnet. She tries four different ways.

1 hammering the magnet

2 heating the magnet

3 passing direct current through the magnet

4 placing the magnet in water

Which methods will demagnetise the magnet?

• 1, 2 and 3

• 1 and 2 only

• 1 and 4

• 2 and 3 only