An initially unmagnetised steel rod is placed inside a solenoid.
Describe:
A mains transformer steps down a voltage of 220 V220\text{ V}220 V to 11 V11\text{ V}11 V. A component in the secondary circuit is connected in series with a 2.5 A2.5\text{ A}2.5 A fuse.
Assuming the transformer is 100%100\%100% efficient, calculate the current in the secondary coil when the current in the primary coil is 0.15 A0.15\text{ A}0.15 A, and predict whether the fuse will blow.
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.