16. Which of the following is not a method of heat transfer? (a) conduction, (b) sublimation, (c) radiation, (d) convection.
17. Transfer of heat through air is primarily by (a) induction, (b) radiation, (c) convection, (d) conduction.
18. Which is the best conductor? (a) empty space, (b) gases, (c) metals, (d) wood.
19. Which is the best transmitter of radiation? (a) gases, (b) empty space, (c) metals, (d) liquids.
20. Heating in space can take place by (a) conduction, (b) convection, (c) radiation, (d) all of the preceding.
21. An object has a temperature of 40°C. What is its temperature in degrees Fahrenheit?
TF = (9/5)TC + 32 TF = (9/5)40 + 32 = ?
22. An object has a temperature of 86°F. What is its temperature in degrees Celsius?
TC = 5/9(TF - 32) TC = 5/9(86 - 32) = ?
23. What is the Kelvin temperature, when the Fahrenheit and Celsius temperatures are equal?
TF = TC = ? TK = TC + 273
24. How much heat is required to raise the temperature of 20 g of water from 10°C to 20°C?
Heat is Q = cm(TF - Ti) Heat is Q = 1cal/g°C(20g)(20 - 10)°C = ?
25. If 200 cal of heat are added to a system, how much energy has been added in joules?
1kcal = 1000 cal 1 cal = 4.18 joules.