Answer:

a) North and south

b) Bar and south

Explanation:

A magnetic compass can trace a bar magnet’s magnetic field lines. The compass can be moved from one bar magnet pole to another. In order to trace the field lines, we move the compass progressively along the field lines.
Create a magnetic field pattern around the magnet. This shows the magnetic field lines leaving the magnet’s north pole and entering its south pole.

The earth’s magnetic field is rather like that of a bar magnet with its south pole in the northern hemisphere.