A straight vertical wire carries a steady electric current. State the shape of the magnetic field lines in a horizontal plane around this current-carrying wire.
A student is provided with the following equipment:
Describe how the student can use this equipment to generate and detect an induced electromotive force (e.m.f.).
State two changes to the apparatus or the procedure that would generate a larger maximum induced e.m.f.
The student then connects a low-frequency alternating current (a.c.) generator in series with a lamp and the centre-zero microammeter. The pointer of the microammeter is observed to swing from side to side repeatedly.
Explain why the pointer moves in this way.
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.