Question

If a current of `4 A` passing through a circuit generates `28 W` of power, what is the resistance of the circuit?

Answer 1

I found: `1.75Omega`

Explanation:

The general expression for power is:
`P=Vi`
where the power `P` represents the energy generated each second, `V` is the potential difference in Volts and `i` is the current.
We can use Ohm's Law here to "extract" the resistance and write: `V=Ri`
into the expression for power:
`P=Ri*i=Ri^2`
so that:
`R=P/i^2=28/16=1.75Omega`