PrintThe questions below are your chance to test and practice your understanding of the content covered in this lesson. In other words, you should be able to answer the following questions if you know the material that was just covered! If you have problems with any of the items, feel free to post your question on the unit message board so your classmates, and/or your instructor, can help you out!
- How is light measured?
- What factors determine the amount of light that is needed in a room?
- What are the three main methods of producing light?
- Explain the difference between incandescence, fluorescence and high intensity discharge.
- What are the common ways in which we can improve the energy efficiency?
- A 60-watt light bulb produces 3 watts of radiant energy and 57 watts of heat energy. What is its efficiency?
- A 100-watt light bulb is left on all day (24 hours). How much did it cost to operate the light bulb if electricity costs 5 cents per kWh?
- A 100 watt incandescent light bulb is operated for 12 hours, and a 15 watt fluorescent light bulb is operated for the same period of time. At 10 cents per kWh, what is the cost savings of the fluorescent bulb?
- Jackie Smith, who is very conscience about environment, would like to know how much energy she can save by switching to fluorescent bulb. Estimate the total energy savings for Jackie who uses a light bulb fixture by comparing the total costs to own and operate 23-Watt CFL bulb instead of 100 Watt incandescent bulb that she has been using. The expected life of incandescent and CFL bulbs is 1,000 h and 8,000 hours. The purchase price of an incandescent bulb is $0.50 and the CFL is $7.50. If Jackie Smith in problem 4 replaces 24 bulbs at home with CFLs, what would be her savings if the electricity cost is $0.085 per kWh?