Electrical power is transmitted from power stations to consumers over long distances using high-voltage overhead cables.
Why is high voltage used for the transmission of electrical power?
High voltage increases the electrical resistance of the cables, making them safer.
High voltage reduces the current flowing through the cables, thereby minimizing energy lost as heat.
High voltage increases the speed of electrons, which reduces the time taken for electrical energy to reach its destination.
High voltage generates large magnetic fields that help repel lightning strikes.
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.