A student sets up an experiment to investigate the magnetic field around a vertical current-carrying wire. The wire passes through a flat horizontal piece of card supported by a stand.
Describe how the student could use a single plotting compass to plot the pattern of the magnetic field lines on the card.
The current in the wire flows vertically upwards. State the shape of the magnetic field lines on the card and describe their direction (clockwise or anticlockwise) when viewed from above. Explain how you determined this direction.
An explorer uses a magnetic compass to find their way. Explain how the behaviour of a magnetic compass provides evidence that the Earth has a magnetic field.