Electric power generated at a station is transmitted over several hundred kilometres…
PHYSICS · Multi-part · A Level · Physics · Fields and their consequences · Fields and their consequences
Problem
Electric power generated at a station is transmitted over several hundred kilometres before it reaches domestic users.
(a) Explain why the voltage is increased at the generating station before transmission through overhead lines.
(b) At the sub-station near a city the voltage is reduced before distribution. Explain how this reduction improves the safety of household wiring.
(c) Using the principle of energy conservation, justify why the current in the long transmission line is much smaller than the current ultimately supplied to domestic loads.