In the national grid, step-up transformers significantly increase the voltage before transmission over long distances. What is the primary physical reason for transmitting power at such a high voltage?
It increases the speed at which electrical energy travels through the cables.
It reduces the current, thereby minimizing the energy wasted as heat due to resistance.
It reduces the electrical resistance of the transmission cables.
It makes the transmission lines much safer to touch.
136 exam-style questions on CIE IGCSE Physics 4.5.6a Construction and operation of a transformer. Each one has a worked solution and a mark scheme showing where the marks go.