During the transmission of electricity across the National Grid, step-up transformers are used to increase the voltage. What is the effect of doing this on the current and the energy dissipated as heat in the cables?
It increases the current, which decreases the heat loss.
It decreases the current, which decreases the heat loss.
It increases the current, which increases the heat loss.
It decreases the current, which increases the heat loss.
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.