An incandesent light bulb has a resistance of 240 `Omega` when lighted. What is the current when connected to a 120 V source?

Expert Answers
ishpiro eNotes educator| Certified Educator

The relationship between the current, voltage and resistance is known as Ohm's Law:

`V = I*r` , where V is voltage, i is current and r is resistance.

Therefore the current through the 240 `Omega` bulb connected to 120-Volt source is

`I=V/r = (120 V)/(240 Omega) = 0.5` Amp

The current is 0.5 Amps.