A student plots one field line by marking the positions of both ends of a compass needle. The student moves the compass so that its south-seeking end is on the previous north-end mark. What should the student do next?
Hold the needle in its previous direction, then mark its new north-end position.
Hold the needle in its previous direction, then rotate the bar magnet towards it.
Wait for the needle to settle, then rotate the bar magnet towards it.
Wait for the needle to settle, then mark its new north-end position.
70 exam-style questions on Edexcel GCSE Physics 12.1 Magnets and magnetic fields, covering 12.1.1 Magnetic poles, 12.1.2 Magnetic materials; permanent and induced magnets, 12.1.3 Magnetic fields, and 12.1.4 Plotting compasses and the Earth's magnetic field. Each one has a worked solution and a mark scheme showing where the marks go.