Unit 17 - Electrical Circuits and their Applications

UNIT 1 REVIEW QUESTIONS ANSWER KEY 1-1) List some of the different ways that homes and buildings may be heated. Wood, gas, oil, electric, solar, heat pumps, and geothermal heating systems are used. 1-2) What were some of the primary heating fuels that early civilizations used? Wood, peat, and coal remained the primary heating fuels for centuries. 1-3) When is it believed that ice was first artificially made for food storage? First evidence of man making ice appeared more than 3,000 years ...