An engineer needs to investigate the magnetic field leakage around a newly designed U-shaped magnetic latch to ensure it does not interfere with nearby sensitive Hall-effect sensors. The latch is secured flat on a sheet of plotting paper.

Describe a step-by-step experimental procedure the engineer can use to map several complete magnetic field lines around this latch using only a single plotting compass and a pencil, and explain how the direction of the magnetic field lines is established.
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.