Question

The heating element in an automobile window

has a resistance of 1.2 ohms when operated at
12 volts. Calculate the power dissipated in the
heating element. [Show all work, including the
equation and substitution with units.]

Answer 1

There are 3 equations for power, P = VI = V^2/R = I^2/R

Given the values you have been given, we know we'll be using V^2/R.

Substituting the values in, we get:

P = 12^2/1.2 = 144/1.2 = 120W