Question

A charge of `40 C` passes through a circuit every `8 s`. If the circuit can generate `5 W` of power, what is the circuit's resistance?

Answer 1

I found: `0.2Omega`

Explanation:

With charge and time you can find current as:
`I=Q/t=40/8=5A`
Using the definition of power and Ohm's Law you get:
`P=VI`
and
`V=RI`
so combining the two:
`P=I^2R`
and rearranging:
`R=P/I^2=5/5^2=1/5=0.2Omega`