Question

The output voltage of a 100.W ideal transformer is 12.0 V and the input current is 20.0 A.a) What is the input voltage?b) What is the output current?c) What kind of transformer is it? (step up or step down)

Answer 1

a) 5 V

b) 8.33 A

c) step-up transformer

Explanation:

a)

To calculate the input voltage it would be:

`\begin{gathered} V_{\text{ in}}=(P)/(I) \\ V_{\text{ in}}=(100)/(20)=5\text{ V} \end{gathered}`

b)

To calculate the output current it would be:

`\begin{gathered} I_{\text{out}}=(P)/(V) \\ I_{\text{out}}=(100)/(12)=8.33\text{ A} \end{gathered}`

c)

We have to:

Step-up transformer increase the output voltage.

Step-down transformer reduces the output voltage.

In this case, the voltage goes from being 5 V to being 12 V, therefore the output voltage increases, which means that it would be a step-up transformer.