How do transformers work?

Question 1

What is the role of a transformer?

Answer 1

Is used to step up or step down a voltage.

Question 2

What is it made of?

Answer 2

An iron core with two coils wrapped around it.

Question 3

Describe what happens in a transformer.

Answer 3

1. An a.c goes through the primary coil.
2. The primary coil produces a m.f which changes as the current changes.
3. The iron core amplifies the strength of this field.
4. The changing m.f induces a changing p.d in the secondary coil.
5. The induced p.d produces an a.c in an external circuit.

Question 4

How do you know whether a transformer steps up or steps down a voltage form its coils?

Answer 4

If it is a step-up transformer, there will be more turn on the secondary coil.

If it is a step-down transformer, there will be more turns on the primary coil.

Question 5

Why is it more efficient to transfer power at a higher voltage?

Answer 5

When the p.d is stepped up, the current decreases which in turn decreases the amount of power consumed.

Question 6

What is the role of the national grid?

Answer 6

It transports electricity around the country.