Question

What is the maximum power consumption of a 3.0-v portable cd player that draws a maximum of 330 ma of current?

Answer 1

The power used by an electrical device is given by:

`P=VI`
where V is the potential difference through the device while I is the current flowing through it.

For the cd-player in our problem,
`V=3.0 V`, while the current is

`I=330 mA=0.33 A`
Therefore, the power used is

`P=VI=(3.0 V)(0.33 A)=0.99 W`