A dip circle (or dipping needle) is a compass whose needle is pivoted vertically, allowing it to measure the angle of the Earth's magnetic field relative to the horizontal (the angle of dip).
Describe how the orientation of the needle of a dip circle changes as it is moved from the Earth's South Magnetic Pole to the Earth's magnetic equator.
What does this global variation in the angle of dip suggest about the magnetic properties of the Earth as a whole?
A student wants to map the magnetic field in the region between and around two permanent bar magnets aligned on a table as shown in the diagram.
Describe how the student can use the plotting compass to map the magnetic field lines in the region surrounding these two magnets.
Describe the pattern and direction of the magnetic field lines in the gap between the two magnets, and explain how the field lines behave as they extend further away from this gap.