Question

If a current of `4 A` passing through a circuit generates `48 W` of power, what is the resistance of the circuit?

Answer 1

`3Omega`

Explanation:

`P=I^2R`

Where `P` is power, `I` is current, and `R` is resistance.

Rearrange for `R`:

`R=P/I^2`

Substitute in values:

`R=48/4^2`

`R=48/16`

`R=3Omega`

Answer 2

`Omega = 3 " ohm"`

Explanation:

`Power = "Voltage" * "Current"`
`"Resistance" = "Voltage"/"Current"`, so
`"Voltage"= "Resistance" * "Current"`, and
`Power = ("Resistance" * "Current") * "Current"`
`Power = "Resistance" * "Current"^2`

In numbers:
`48"W" = Omega * 4^2"A"`
`48/16 = Omega`
`Omega = 3 " ohm"`