A current-carrying solenoid produces a magnetic field around it. How do the strength of the magnetic field and the spacing of the magnetic field lines change if the current in the solenoid is decreased?
Spacing of field lines: closer together; Strength of field: stronger
Spacing of field lines: closer together; Strength of field: weaker
Spacing of field lines: further apart; Strength of field: stronger
Spacing of field lines: further apart; Strength of field: weaker
275 exam-style questions on CIE IGCSE Physics 4.5 Electromagnetic effects, covering 4.5.1a Electromagnetic induction, 4.5.1b Direction of an induced e.m.f., 4.5.2 The a.c. generator, 4.5.3a Magnetic effect of a current and its applications, 4.5.3b Strength and direction of the field around wires and solenoids, 4.5.4a Force on a current-carrying conductor, 4.5.4b Force on beams of charged particles, 4.5.5 The d.c. motor, 4.5.6a Construction and operation of a transformer, 4.5.6b Turns ratio and current in a transformer, and 4.5.6c High-voltage transmission of electricity. Each one has a worked solution and a mark scheme showing where the marks go.