Transformers Change the Voltage - but Only Alternating Voltages Flashcards
1
Q
What do transformers change the size of?
A
The voltage of an alternating current
2
Q
How many coils do they all have?
A
2 - the primary and the secondary, joined with an iron core
3
Q
What happens when an alternating voltage is applied across the primary coil?
A
The magnetically soft (iron) core magnetises and demagnetises quickly
4
Q
What does this induce?
A
An alternating current in the secondary coil
5
Q
What is the ratio between primary and secondary voltage the same as?
A
The ratio between the number of turns on the primary and secondary coils
6
Q
What do step-up transformers do?
A
- increase the voltage
- has more turns on the secondary coil than primary coil
7
Q
What do step-down transformers do?
A
- decrease the voltage
- has more turns on the primary coil than the secondary
8
Q
Check out diagrams page 64
A
Ok
