(Original post by coolgirlaamy)
Hi. I got an A band 1 in physics last year and since im going into engineering, I thought I should give AH physics a try. So far its been okay-ish but I suppose the hardest thing is just knowing what formulas to use and how to derive different equations during a question.
My investigation is the proportional relationship between magnetic flux density B and current I and I just have to do my last experiment before I get to the report and trying to do my uncertainties.
Helmholtz coils are quite accurate arrangement for producing a linear magnetic field, paraxial and central of course, the only problem is getting the central axis of the coils aligned - can be tricky. You can measure the B- field strength with a semiconductor probe (Hall Effect calibrated of course). Be careful to ensure that the probe is orientated precisely - using twist until you get maximum reading etc. The desk and clamps can affect the results- think shielding! Lots to try and write up- take lots of readings, more than one set in any run. There is also a way to measure the force produced by a wire carrying a current through the poles of an electromagnet F=Bil technique, using a weighing machine pan etc - you could maybe do both experiments.
The Helmholtz coil stuff at: link
The top-pan balance experimental method is well covered in the doc: link
Good luck, to really impress your markers best to do an Excel sheet with plots etc as explained in my web-site
(mentioned in previous post).
IMPORTANT: sketch or photos of your experimental setup showing important equipment, what you are measuring, how you measured what and the calibration of your equipment - especially current meters or probes.
Try to produce a direct-proportional graph - slope!
Your graphs must show measurement errors bars.