Question

Which of the following is a transformer used for?
Answer

Alternate a voltage

Produce a voltage

Increase or decrease a voltage

Eliminate a voltage

Answer 1

Increase or decrease a voltage

Answer 2

Transformers are mainly used to avoid loss of excessive energy in the transmission lines.
For example from the transmission lines from the substation to houses, you don't want too much current to go through the wire as excessive current results in heat loss to the surrounding and less efficient and costs very expensive.

Answer 3

Therefore with transformers, we can step up or step down the voltage,
From the equation P = VI , we can see that for a constant power, when we step up the voltage, our current goes down thus avoid losing energy.