A transformer contains a core made of iron. Why is a magnetically soft material, such as iron, used for the core of a transformer instead of a magnetically hard material like steel?
Iron is an electrical insulator, preventing short circuits between the primary and secondary coils.
Iron can be easily magnetized and demagnetized, reducing energy losses from alternating magnetic fields.
Iron maintains a permanent magnetic field, eliminating the need for an alternating input voltage.
Iron conducts the electric current directly from the primary coil to the secondary coil.
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.