electricity - the national grid

Question 1

what is the national grid

Answer 1

it is a system that includes transformers and transmission cables to transmit electricity from power stations to consumers across the country

this enables all consumers to access electricity generated elsewhere in the country, when their local power station is out of action, or cannot meet local demand

Question 2

step up transformers

Answer 2

• increase voltage
• decrease current so wires do not get as hot and thermal energy is not lost to the surroundings

Question 3

step down transformers

Answer 3

• increase current
• decrease voltage to safer, practical levels for the consumer use

Question 4

transmission lines

Answer 4

• made from uninsulated aluminium (light) to save on cost
• they must be supported by high pylons to ensure they are out of our reach
• burying cables underground will be safe, prettier, and shielded from poor weather but they cost more and are difficult to maintain