A light bulb,sold as long-lasting,is rated 95 W at 145 V.The "increased" lifetime comes from using it at 105 V.Assuming negligible change in resistance at the different voltage,what is its power consumption at 105 V?

Question

Quizplus · Accepted Answer

The power consumption can be calculated using the formula P = V^2 / R. First, find the resistance using the rated values: R = (145 V)^2 / 95 W. Then, use this resistance to find the power at 105 V: P = (105 V)^2 / R, which gives approximately 50 W.

A Light Bulb,sold as Long-Lasting,is Rated 95 W at 145