Electricity generation - CCEAHigher tier: Transformers and current

When a transformer steps-up voltage it has exactly the opposite effect on the current.

The current is stepped-down or decreased in size.

As we will see, this is very useful when transmitting electricity from a power station across country to your home.

Likewise, a step-down transformer steps-down the voltage but steps-up the current.

Key points

A step-up transformer:

• Steps-up voltage.
• Steps-down current.
• Has more turns of wire on the secondary coil.

A step-down transformer:

• Steps-down voltage.
• Steps-up current.
• Has fewer turns of wire on the secondary coil.