Question

How much power is produced if a voltage of `7 V` is applied to a circuit with a resistance of `42 Omega`?

Answer 1

The power is `=1.17W`

Explanation:

The power is

`P=UI`

and Ohm's Law is

`U=RI`

`I=U/R`

Therefore,

`P=U*U/R=U^2/r`

The voltage is `U=7V`

The resistance is `R=42 Omega`

Therefore,

The power is

`P=(7^2)/42=49/42=1.17W`

Answer 2

Approximately `1.17` watts.

Explanation:

Power in here is given by the equation:

`P=V^2/R`

where:

• `P` is the power in watts

• `V` is the voltage in volts

• `R` is the resistance in ohms

So, we get:

`R=(7 \ "V")^2/(42 \ Omega)`

`=(49 \ "V"^2)/(42 \ Omega)`

`~~1.17 \ "W"`