# When a 120 V potential difference is applied across a

When a 120 V potential difference is applied across a $30\mathrm{\Omega }$ resistance of electric device. What is the current through the electric device? What is the power of the electric device?
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odvucimo1pp17
Apply Ohm's Law
voltage = Resistance $×$ Current
U=RI
The voltage is U=120V
The resistance is $R=30\mathrm{\Omega }$
The current is
$I=\frac{U}{R}=\frac{120}{30}=4A$
The power is
P=UI=120*4=480W
###### Not exactly what you’re looking for?
Stoyanovahvsbh
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,
$120V=I\ast 30\mathrm{\Omega }$
$I=\frac{120V}{30\mathrm{\Omega }}$
=4A
To find the power, we use the equation,
P=IV
So, the power here is:
P=4A*120V
=480W