P4.2.5 - Transformers

Question 1

What is a transformer used for?

Answer 1

Increasing or decreasing a potential difference

Question 2

How can you change the field lines that cut the coil?

Answer 2

Move the magnet or coil
Use another coil and turn the current in it on and off
Use another coil with AC

Question 3

What is a transformer?

Answer 3

A loop of iron with two coils that traps a magnetic field in the iron core

Question 4

Describe how the transformer works.

Answer 4

An alternating potential difference across the primary coil produces an alternating current in the primary coil
An alternating current in the primary coil produces a magnetic field in the iron core that is always changing
This induces a changing potential difference in the secondary coil

Question 5

What is the relationship between the potential differences of both primary and secondary coil?

Answer 5

Potential difference of primary coil / potential difference of secondary coil

number of turns in primary coil / number of turns in secondary coil

Question 6

What is a step-up transformer?

Answer 6

A transformer which increases the potential difference

Question 7

What is a step-down transformer?

Answer 7

A transformer which decreases the potential difference