Transformers

Question 1

Explain how transformers work

Answer 1

They change the size of a voltage of an altering current
They have a primary coil and a secondary coil that are joined with an iron core
An alternating current is applied across the primary coil, the ‘soft’ iron core magnetises and demagnetises quickly, this induces an alternating voltage in the secondary coil

Question 2

How to step up transformers work

Answer 2

They have more turns on the secondary coil than the primary coil causing them to increase the voltage

Question 3

How do step down transformers work

Answer 3

More turns on the primary coil than the secondary coil causing them to decrease the voltage

Question 4

How do transformers increase efficiency of mains electricity transmission

Answer 4

The voltage produced from power stations is too low for efficient transmission, the lower the voltage the higher the current for a given power, and current causes the wires to heat up
Step up transformer is used to boost the voltage before it is transmitted
Step down transformers are used at the end of the journey to reduce the voltage so it’s more useful and safer to use