The National Grid

Potential difference

________ is increased using a step- up transformer.

Transformers

________ are nearly 100 % efficient, so the power in primary coil= power in secondary coil.

Nation Grid

Electricity is distributed via the ________.

Potential difference

________ is changed by a transformer.

400,000V

Voltage is______ for efficient transmission

high pd and low current

The national grid uses

current in secondary coil = p.d. across primary coil

p.d across secondary coil x_________________ x current in primary coil

as low as possible

For it to be cheap, keep the current_______

in the morning and evening

Demand is highest__________

below maximum output

Power stations run_________