Which statement compares the magnetic field outside a long solenoid with the field of a bar magnet?
It has the same shape, but the poles stay fixed when the current is reversed
It has a different shape, and its lines form circles around the whole coil
It has a different shape, but the poles swap when the current is reversed
It has the same shape, and its poles swap over when the current is reversed
44 exam-style questions on OCR GCSE Physics 4.1 Magnets and magnetic fields, covering 4.1.1 Magnetic poles, attraction and repulsion, 4.1.2 Permanent and induced magnets, 4.1.3 The magnetic field of a magnet, 4.1.4 Compasses and the Earth's magnetic field, 4.1.5 The magnetic field around a current-carrying wire, 4.1.6 Field strength, current and distance, and 4.1.7 Solenoids and electromagnets. Each one has a worked solution and a mark scheme showing where the marks go.