Physics (AS & A Level) · Oct / Nov 2016 · Paper 52 · Question 1

A student uses a Hall probe to investigate the magnetic flux density due to a U-shaped electromagnet, as shown in Fig. 1.1. p P iron core coil Fig. 1.1 Point P is equidistant from the poles of the electromagnet and distance p is the vertical distance between P and the top of the electromagnet. The magnetic flux density is B at point P. It is suggested that the relationship between B and p is B = kNIe−αp where N is the number of turns on the coil, I is the current in the coil and α and k are constants. Design a laboratory experiment using a Hall probe to test the relationship between B and p. Explain how your results could be used to determine values for α and k. You should draw a diagram, on page 3, showing the arrangement of your equipment. In your account you should pay particular attention to • the procedure to be followed, • the measurements to be taken, • the control of variables, • the analysis of the data, • any safety precautions to be taken. [15] 3 Diagram 4 [Total: 15]

Read automatically from the paper; the printed page above is exact.