Question

A light bulb, after it has reached its operation temperature, is connected across a potential difference of 120V while 0.5A of current passses through it. What is the resistance of the light bulb?

Answer 1

E = IR
120 = 0.5R
Solve for R.

Answer 2

120/0.5 = 0.5R/0.5

= 240 ohms