physics: national grid

What is the national grid?

a giant system of cables and transformers that cover the whole of the UK.

Why do power outputs often run at well below their maximum power outputs?

so there is spare capacity to cope with a high demand.

What do you need to transmit the huge amount of power needed?

A high potential difference or a high current.

What is the problem with a high current?

A lot of energy is lost in the process.

Why is energy lost when using a high current?

The wires heat up and energy is transferred to the thermal energy store of the surroundings.

What makes the national grid effective?

increasing the potential difference of a power, will decrease the current, which decreases the energy lost by heating the wires and surroundings.

What two coils do transformers have?

A primary coil and a secondary coil, which are joined with an iron core.