Question

If a current of `4 A` passing through a circuit generates `16 W` of power, what is the resistance of the circuit?

Answer 1

1 `Omega`

Explanation:

We will be using two formulas: the one for power, to calculate voltage, and Ohm's Law, to calculate resistance.

Power is given by: `P=IE`, where `I` is the current and `E` is the voltage. We are given the power (16 watts), and the current (4 amps), and we can use these to get the voltage:
`16=4E`
`16/4=E`
`E=4` volts

Now we use Ohm's Law, which states that `V=IR`, where `V` is the voltage, `I` is current, and `R` is resistance. We have the voltage (4 volts) and current (4 amps), so all we do is substitute:
`4=4R`
`4/4=R`
`R=1` ohm

Therefore, the resistance is 1 `Omega`.