An engineer is testing two newly synthesized ferromagnetic alloys shaped into identical cylindrical rods, Rod A and Rod B.
To compare their magnetic field strengths, they set up the apparatus shown below using a non-magnetic plastic ruler and a single small steel paperclip.

Describe how the engineer could use this setup to determine which of the two alloy rods is the stronger magnet.
Practise Edexcel GCSE Physics Magnets and magnetic fields with exam-style questions for Foundation and Higher tier. 100 questions, matched to the Edexcel GCSE Physics (1PH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.