Question

When a 120 V potential difference is applied across a 30 Ω resistance of electric device. What is the current through the electric device? What is the power of the electric device?

Answer 1

Please, find the explanation below

Explanation:

Apply Ohm's Law

`"voltage" = "Resistance" xx "Current"`

`U=RI`

The voltage is `U=120V`

The resistance is `R=30 Omega`

The current is

`I=U/R=120/30=4A`

The power is

`P=UI=120*4=480 W`

Answer 2

The current is `4` amps, while the power is `480` watts.

Explanation:

We first find the current flowing through the device using Ohm's law, which is:

`V=IR`

• `I` is the current in amperes

• `R` is the resistance in ohms

And so,

`120 \ "V"=I*30 \ Omega`

`I=(120 \ "V")/(30 \ Omega)`

`=4 \ "A"`

To find the power, we use the equation,

`P=IV`

So, the power here is:

`P=4 \ "A"*120 \ "V"`

`=480 \ "W"`