Practice Questions

1.State what a transformer is used for

A transformer is used to either increase or decrease the size of an alternating potential difference. 

2. Describe the construction of a transformer

Every transformer will contain a primary coil, secondary coil and iron core.

Both of the coils are wound around the soft iron core.

3. Explain how a transformer can increase the size of an alternating potential difference. 

A small alternating potential difference is applied across the primary coil, an alternating current will flow in the primary coil. 

This alternating current through primary coil, will cause a changing magnetic field through the soft iron core. 

The magnetic field lines will cut the secondary coil, inducing a large alternating potential difference across the ends of the coil. 

If the secondary coil is part of a complete circuit, then an altnernating current will flow.