Chapter 19, Problem 74PP

Refrigerators remain among the greatest consumers of electrical energy in most homes, although mandated efficiency standards have decreased their energy consumption by some 80% in the past four decades. In the course of a day, one kitchen refrigerator removes 30 MJ of energy from its contents, in the process consuming 10 MJ of electrical energy. The electricity comes from a 40% efficient coal-fired power plant.

The electrical energy

1. a. is used to run the light bulb inside the refrigerator.
2. b. wouldn’t be necessary if the refrigerator had enough insulation.
3. c. retains its high-quality status after the refrigerator has used it.
4. d. ends up as waste heat rejected to the kitchen environment.