An 80W Incandescent Lightbulb Efficiency and Heat Production

Calculating Heat Production

Final Answer: An 80W incandescent lightbulb with 2% efficiency uses 1.6W for light, which means that the rate at which it produces heat is 78.4W.


Explanation: If an 80W incandescent lightbulb is 2% efficient, then we can calculate the rate at which it produces heat by first determining how much of the energy is used for light and how much is lost as heat. With 2% efficiency, 2% of the electrical power is converted into light and the rest is lost as heat. Thus, if we have a total power consumption of 80W, we can find the power used for light and subtract this from the total power to find the power lost as heat.


The power used for light is 2% of 80W, which is 0.02 × 80W = 1.6W. The rate at which it produces heat is therefore 80W - 1.6W = 78.4W.

← Special relativity and kinematics exploring projectile launchers in the lab The speedy water adventure →