sorry its really crappy... again. lol.
um.. basically try and show that the hall probe is positioned at right angles to the flux coming through the coil, like 3D- it would take me forever to do that on paint- sorry.
I took the hall probe image from what was in a paper 4 question. Remember to mention the current through the probe is constant.... i dont know if thats needed for this - but in the diagram i drew that my teach checked - i drew like this flat square sheet like thing connected to a Volmeter across one side and a power supply across the other side (if that makes sense?), and labelled it 'precalibrated hall probe' ... and the only correction on that was to 'state a constant current thru probe'.