The National Grid Flashcards
All 5 cards in this deck
What is the national grid?
The network of cables, pylons and transformers that transfers electrical power from power stations to consumers.
Where in the national grid is a step-up transformer used, and why?
Between the power station and the transmission lines, to raise the p.d. so the current is smaller and less energy is wasted as heat.
Where in the national grid is a step-down transformer used, and why?
In each locality before homes and businesses, to lower the p.d. to a safe, usable value (about 230 V).
True or false? Electrical energy is transferred across the national grid at high current to improve efficiency.
False. It is transferred at high potential difference and low current, which reduces heating losses.
What is a typical potential difference used in national grid transmission lines?
About V (compared with 230 V for domestic supply).