A 100 watt incandescent light bulb is operated for 7 hours, and a 32 watt fluorescent light bulb is operated for the same period of time. At 8 cents per kWh, what is the cost savings in using the fluorescent bulb?

Question

Physics

Declan Wheeler

15 July, 13:45

A 100 watt incandescent light bulb is operated for 7 hours, and a 32 watt fluorescent light bulb is operated for the same period of time. At 8 cents per kWh, what is the cost savings in using the fluorescent bulb?

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Answers (1)

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Julius Sexton · Answer 1

Cost savings in using the fluorescent bulb is 3.81 cents

Explanation:

A 100 watt incandescent light bulb is operated for 7 hours.

Energy used by 100 watt incandescent light bulb = Power x Time

Energy used by 100 watt incandescent light bulb = 100 x 7 = 700 Wh

Energy used by 100 watt incandescent light bulb = 0.7 kWh

A 32 watt fluorescent light bulb is operated for 7 hours.

Energy used by 32 watt fluorescent light bulb = Power x Time

Energy used by 32 watt fluorescent light bulb = 32 x 7 = 224 Wh

Energy used by 32 watt fluorescent light bulb = 0.224 kWh

Cost of electricity per kWh = 8 cents

Cost of electricity by 100 watt incandescent light bulb = 0.7 x 8 = 5.6 cents

Cost of electricity by 32 watt fluorescent light bulb = 0.224 x 8 = 1.792 cents

Difference in costs = 5.6 - 1.792 = 3.808 cents

Cost savings in using the fluorescent bulb is 3.81 cents