6.18 Explain the use of step-up and step-down transformers in the largescale generation and transmission of electrical energy

Transformers in the national grid are used to stop the wires from overheating - a very high current flowing through very long wires would produce a lot of heat, because the wires have some resistance.

• Step up transformers increase the voltage, decrease the current to stop energy waste through heat when passing through long wires

• In households, wires are shorter so there's less heat wasted, so step down transformer decreases voltage and increases current to make it more useful to us.