Question

How much power is used by a calculator that operates on 8 volts and 0.1 amperes? If it is used for one hour, how much energy does it use?

kindly add solution thank you!

Answer 1

$$P=VI\\ =\rm 8\: V\times 0.1\: A=0.8\: W$$

$$W=Pt\\ =\rm 0.8\: W\times 3600\: s=32727 \: J$$