Question

Part (b)A cassette recorder uses a plug-in transformer to convert 120 V to 12.0 V, with a maximum current output of 355 mA. (b) What is the power input (in W)?

Answer 1

Given

The input voltage, V=120 V

The output voltage, V'=12.0 V

Current output is I'=355 mA

To find

(b) What is the power input (in W)?

Step-by-step explanation

We know,

`\begin{gathered} VI=V^(\prime)I^(\prime) \\ \Rightarrow120I=12*355*10^(-3) \\ \Rightarrow I=0.0355\text{ A} \end{gathered}`

The power input is

`\begin{gathered} P=IV \\ \Rightarrow P=120*0.0355 \\ \Rightarrow P=4.26\text{ W} \end{gathered}`

Conclusion

The power input is 4.26 W