Transfmormers

Question 1

What is the role of a transformer?

Answer 1

• Step-up transformer: increases voltage to minimise energy loss
• Step-down transformer: decreases voltage to make it safe to use

Question 2

Structure of a transformer

Answer 2

• Primary coil and secondary coil wrapped around an iron core
• Primary coil and secondary coil are on opposite sides of the core

Question 3

How does a transformer work?

Answer 3

• Alternating potential difference is fed through the priary coil, which sets up an alternating magnetic field
• This induces an alternating magnetic field in the iron core
• This induces an alternating magnetic field in the secondary coil which allows current to flow (if the circuit is complete)

Question 4

How does a transformer change the voltage?

Answer 4

• The number of times amount of loops in the secondary coil is greater or less than the primary coil is by how much the voltage will change
• E.G: secondary coil has 2 times more loops than primary coil = voltage will double

Question 5

Why do we need to use an alternating current in transformers?

Answer 5

• As an alternating current swaps the direction in which the current flows, the magnetic field would move and be able to induce a current in the secondary coil (due to the generator effect)
• If the current was direct, it would not change and therefore wouldn’t be able to induce a current in the secondary coil