Magnetism Practice Questions

Which one of these materials is magnetic?

Put a cross ( ☒ ) in the box next to your answer.

☐ A aluminium

☐ B cobalt

☐ C copper

☐ D zinc

Explain why iron is a suitable material for the plate on the cupboard door.

State whether magnet B will be attracted towards magnet A or repelled away from magnet A.

Magnet B is now turned round through $180°$, so that its S-pole faces magnet A.

State and explain what happens to magnet B.

Draw arrows on the field lines in Figure 2 to show the direction of the magnetic field.

State whether the magnetic field is stronger at point P or at point Q. Give a reason for your answer.

Explain why the paper clips are attracted to the iron nail.

The teacher takes the nail away from the magnet and, a short time later, holds the nail near some more paper clips.

State and explain what is observed.

Explain how this behaviour of the compass needle is evidence that the core of the Earth is magnetic.

The north pole of the compass needle points towards the geographic North Pole of the Earth.

State what this tells you about the magnetic pole of the Earth that is near the geographic North Pole.

On Figure 3, draw three magnetic field lines in the gap between the two magnets to show the magnetic field there.

Show the direction of the field on each line.

The magnetic field in the gap is described as a uniform field.

Give two ways in which a uniform field is different from the magnetic field around a single bar magnet.

A student is given a bar magnet, a plain sheet of paper, a sharp pencil and one plotting compass.

Describe how the student can use this equipment to produce a diagram showing the shape and the direction of the magnetic field around the bar magnet.

Your answer should also explain how the finished diagram shows where the field is strongest.

In a demonstration, a ring magnet is threaded onto a vertical plastic rod above a second, fixed ring magnet. Like poles face each other, so the upper magnet floats at rest a distance $d$ above the lower magnet.

The repulsive force $F$ between the magnets is given by the equation

$$F = \frac{K}{d^2}$$

where $K = 4.8 \times 10^{-5}\ \mathrm{N\,m^2}$ and $d$ is measured in metres.

The mass of the upper magnet is $12\ \mathrm{g}$.

(gravitational field strength, $g = 10\ \mathrm{N/kg}$)

Calculate the distance $d$.

$d$ = .............................................. m