## 02.6. thermodynamics

Question Number. 1. Convert 25 degrees centigrade to fahrenheit.

Option A. 57.

Option B. 77.

Option C. -7.

Correct Answer is. 77.

Explanation. (25*1.8)+32= 77.

Question Number. 2. You are at the north pole where the temperature is minus 50 °C below freezing. What sort of thermometer would you use to measure it?.

Option A. Water.

Option B. Alcohol.

Option C. Mercury.

Correct Answer is. Alcohol.

Explanation. NIL.

Question Number. 3. Convert 15 °C to °F.

Option A. 37 °F.

Option B. 59 °F.

Option C. 62 °F.

Correct Answer is. 59 °F.

Explanation. ISA sea level temperature 15 °C = 59 °F.

Question Number. 4. 1 degree rise on the centigrade scale will cause a.

Option A. 1.8 degree rise in Fahrenheit.

Option B. 33 degree rise in Fahrenheit.

Option C. 0.911 degree rise in Fahrenheit.

Correct Answer is. 1.8 degree rise in Fahrenheit.

Explanation. NIL.

Question Number. 5. 1 calorie is equal to.

Option A. 4 J.

Option B. 40 J.

Option C. 400 J.

Correct Answer is. 4 J.

Explanation. NIL.

Question Number. 6. 1 BTU equals.

Option A. 1055 Joules.

Option B. 1055 Calorie.

Option C. 1055 kJ.

Correct Answer is. 1055 Joules.

Explanation. NIL.

Question Number. 7. Temperature is a measure of.

Option A. the amount of friction produced by two mating surfaces.

Option B. the amount of vibration of molecules.

Option C. the heat energy of particles.

Correct Answer is. the amount of vibration of molecules.

Explanation. Heat energy applied to an object does not necessarily increase temperature (eg. when melting or evaporating).

Question Number. 8. What temperature scale is used with the combined gas law?.

Option A. Absolute.

Option B. Fahrenheit.

Option C. Celsius.

Correct Answer is. Absolute.

Explanation. Kelvin (absolute scale) is always used with the combined gas law equation.";.

Question Number. 9. What is 1 btu/lb in joules per kilogram?.

Option A. 2326 j/kg.

Option B. 4128 j/kg.

Option C. 9.18 j/kg.

Correct Answer is. 2326 j/kg.

Explanation. This is referring to specific energy content (J/kg or Btu/lb) of fuel. 1 btu = 1055 J. 1 lb = 2.2 kg. Therefore 1 btu = 2326 J/kg.

Question Number. 10. 1 CHU = Centigrade Heat Unit = 1400 ft lbs =energy to raise.

Option A. 1 lb of water by 1 °F.

Option B. 1 kg of water by 1 °C.

Option C. 1 lb of water by 1 °C.

Correct Answer is. 1 lb of water by 1 °C.

Explanation. 1 CHU is the heat required to raise 1 lb of water 1 degree Centigrade (=1.8 BTU).

Question Number. 11. 1 BTU = 778 ft lbs which is the energy required to raise the temperature of.

Option A. 1 lb of water by 1 °F.

Option B. 1 kg of water by 1 °F.

Option C. 1 lb of water by 1 °C.

Correct Answer is. 1 lb of water by 1 °F.

Explanation. 1 BTU is the heat required to raise 1 lb of water 1 degree Fahrenheit.

Question Number. 12. A temperature of 41 degrees Fahrenheit is, in Centigrade.

Option A. 9 degrees.

Option B. 5 degrees.

Option C. 7 degrees.

Correct Answer is. 5 degrees.

Explanation. C = 5/9(F-32).

Question Number. 13. Heat is described as.

Option A. a high temperature.

Option B. energy in transit.

Option C. the stored energy in a hot body.

Correct Answer is. energy in transit.

Explanation. Heat is a type of transfer of energy which increases the kinetic energy of the molecules within a body.

Question Number. 14. 600K is equal to.

Option A. 853 °C.

Option B. 873 °C.

Option C. 326.85 °C.

Correct Answer is. 326.85 °C.

Explanation. Subtract 273.15.

Question Number. 15. When gases change temperature/pressure, the scale used is.

Option A. Kelvin.

Option B. degrees Fahrenheit.

Option C. degrees Centigrade.

Correct Answer is. Kelvin.

Explanation. Always use the Kelvin scale in thermodynamics.

Question Number. 16. Convert 100 °C to Kelvin.

Option A. 173 K.

Option B. 373 K.

Option C. 273 K.

Correct Answer is. 373 K.

Explanation. Degrees C to Kelvin - just add 273.

Question Number. 17. -40 °C in Fahrenheit is.

Option A. 72 °F.

Option B. 8 °F.

Option C. -40 °F.

Correct Answer is. -40 °F.

Explanation. °F = 1.8 °C + 32 1.8(-40) + 32 = -40 °F. Please do not report this as an error.

Question Number. 18. Absolute zero is.

Option A. 0 °C.

Option B. 273.15 K.

Option C. -273.15 °C.

Correct Answer is. -273.15 °C.

Explanation. Absolute zero is - 273.15 degrees Celsius.

Question Number. 19. One degree increment on the Centigrade scale is equal to what increment on the Fahrenheit scale?.

Option A. 1.8 °F.

Option B. 33 °F.

Option C. 12 °F.

Correct Answer is. 1.8 °F.

Explanation. A change of' 1 degree C. it is equal to 'a change of' 1.8 degree F.

Question Number. 20. Transfer of heat from a hot area to a cold area is.

Option A. conduction.

Option B. convection.

Option C. radiation.

Correct Answer is. conduction.

Explanation. Convection is a transfer of 'matter' from one place to another. Radiation is a system which heats up anything in its path. but heat is not 'transferred'.

Question Number. 21. Fahrenheit may be converted to Celsius by using the equation.

Option A. °C = 5/9 * ( °F - 32).

Option B. °C = 5/9 * °F - 32.

Option C. °C = 9/5 * °F + 32.

Correct Answer is. °C = 5/9 * ( °F - 32).

Explanation. °C = 5/9( °F-32). °F = 9/5 °F + 32.

Question Number. 22. What is 1 BTU/lb in joules per kilogram?.

Option A. 4128 joules per kilogram.

Option B. 9.18 joules per kilogram.

Option C. 2326 joules per kilogram.

Correct Answer is. 2326 joules per kilogram.

Explanation. 1 BTU/lb = 2326 j/kg. This is referring to heat of combustion of fuel.

Question Number. 23. Celsius to Fahrenheit is calculated by.

Option A. (9/5 * °C) + 32.

Option B. (5/9 * °C) + 32.

Option C. (5/9 + 32) + °C.

Correct Answer is. (9/5 * °C) + 32.

Explanation. Remember standard sea level temperature is 15 °C and 59F. Make °C = 15 on each formula above, and see which comes out at 59 °F".

Question Number. 24. The percentage of nitrogen in air is approximately.

Option A. 0.62.

Option B. 0.21.

Option C. 0.78.

Correct Answer is. 0.78.

Explanation. NIL.

Question Number. 25. When a system undergoes a complete cycle where the net heat supplied is equal to work done plus a change in internal energy - this is known as.

Option A. 2nd Law of thermodynamics.

Option B. First law of thermodynamics.

Option C. Ideal Gas law.

Correct Answer is. First law of thermodynamics.

Explanation. NIL.

Question Number. 26. In a heat pump.

Option A. the evaporator gains heat during the heating cycle.

Option B. the condenser always loses heat.

Option C. the pump operates in both directions.

Correct Answer is. the pump operates in both directions.

Explanation. NIL.

Question Number. 27. What is -28 °C on the Kelvin scale?.

Option A. 245 K.

Option B. 18 K.

Option C. 291 K.

Correct Answer is. 245 K.

Explanation. -28 + 273 = 245.

Question Number. 28. When water freezes, heat energy is.

Option A. absorbed.

Option B. retained.

Option C. released.

Correct Answer is. released.

Explanation. Freezing is 'exothermic'.

Question Number. 29. 842 degrees Fahrenheit is equal to.

Option A. 450 Degrees Celsius.

Option B. 400 Degrees Celsius.

Option C. 232.2 degrees Celsius.

Correct Answer is. 450 Degrees Celsius.

Explanation. C = 5/9(F - 32).

Question Number. 30. For a fixed mass of water at sea level ISA conditions and at 10,000ft.

Option A. the water will boil at a lower temperature than sea level.

Option B. the water will boil at the same temperature as sea level.

Option C. the water will boil at a higher temperature than sea level.

Correct Answer is. the water will boil at a lower temperature than sea level.

Explanation. As pressure drops, so does the boiling temperature.

Question Number. 31. Dew point is.

Option A. the temperature at which condensation actually occurs.

Option B. the temperature below which condensation occurs.

Option C. the temperature above which condensation occurs.

Correct Answer is. the temperature below which condensation occurs.

Explanation. NIL.

Question Number. 32. By adding impurities to water.

Option A. the melting point will increase and the boiling point decrease.

Option B. there will be no effect to the melting and boiling points.

Option C. the melting point will decrease and the boiling point will increase.

Correct Answer is. the melting point will decrease and the boiling point will increase.

Explanation. NIL.

Question Number. 33. Which type of circuit is used when the temperature of the source has insufficient heat for thermocouple application?.

Option A. thermistor.

Option B. temperature bulb.

Option C. balanced bridge.

Correct Answer is. thermistor.

Explanation. NIL.

Question Number. 34. Four pounds of gas at a temperature of 17 °C is heated to 89 °C. The specific heat at constant pressure and constant volume are 0.2404 and 0.1718 respectively. Find the heat absorbed by the gas at constant pressure and at constant volume.

Option A. 70.1 C.H.U. and 50 C.H.U.

Option B. 49.5 C.H.U. and 69 C.H.U.

Option C. 69.2 C.H.U. and 49.5 C.H.U.

Correct Answer is. 69.2 C.H.U. and 49.5 C.H.U.

Explanation. Q = mC(T2 -T1), 4 * 0.2404 * 72 = 69.2 CHU, and 4 * 0.1718 * 72 = 49.5 CHU.

Question Number. 35. In 'standard conditions' what is the standard for measurement of volume and density of a gas?.

Option A. 0 °C and 760mm of Mercury.

Option B. 20 °C and 700mm of Mercury.

Option C. 20 °C and 760mm of Mercury.

Correct Answer is. 0 °C and 760mm of Mercury.

Explanation. STP also applies to solids and liquids.

Question Number. 36. In 'standard conditions' what is the standard for measurement of volume and density of a liquid or solid?.

Option A. 20 °C and 760mm of Mercury.

Option B. 0 °C and 760mm of Mercury.

Option C. 20 °C and 700mm of Mercury.

Correct Answer is. 0 °C and 760mm of Mercury.

Explanation. NIL.

Question Number. 37. 842 Degrees Fahrenheit is equal to.

Option A. 450 Degrees Celsius.

Option B. 232.2 Degrees Celsius.

Option C. 400 Degrees Celsius.

Correct Answer is. 450 Degrees Celsius.

Explanation. NIL.

Question Number. 38. Which of the following 2 points are equal?.

Option A. -32 °C and 0 °F.

Option B. 40 °C and 40 °F.

Option C. -40 °C and -40 °F.

Correct Answer is. -40 °C and -40 °F.

Explanation. NIL.

Question Number. 39. What is 100 Degrees Centigrade in Fahrenheit?.

Option A. 30 Degrees.

Option B. 148 Degrees.

Option C. 212 Degrees.

Correct Answer is. 212 Degrees.

Explanation. NIL.

Question Number. 40. The absolute temperature scale that has the same increments as the Fahrenheit scale is the.

Option A. Rankin scale.

Option B. Kelvin scale.

Option C. Celsius scale.

Correct Answer is. Rankin scale.

Explanation. NIL.

Question Number. 41. The absolute temperature scale that has the same increments as the Celsius scale is the.

Option A. Rankin scale.

Option B. Kelvin scale.

Option C. Fahrenheit scale.

Correct Answer is. Kelvin scale.

Explanation. NIL.

Option A. 57.

Option B. 77.

Option C. -7.

Correct Answer is. 77.

Explanation. (25*1.8)+32= 77.

Question Number. 2. You are at the north pole where the temperature is minus 50 °C below freezing. What sort of thermometer would you use to measure it?.

Option A. Water.

Option B. Alcohol.

Option C. Mercury.

Correct Answer is. Alcohol.

Explanation. NIL.

Question Number. 3. Convert 15 °C to °F.

Option A. 37 °F.

Option B. 59 °F.

Option C. 62 °F.

Correct Answer is. 59 °F.

Explanation. ISA sea level temperature 15 °C = 59 °F.

Question Number. 4. 1 degree rise on the centigrade scale will cause a.

Option A. 1.8 degree rise in Fahrenheit.

Option B. 33 degree rise in Fahrenheit.

Option C. 0.911 degree rise in Fahrenheit.

Correct Answer is. 1.8 degree rise in Fahrenheit.

Explanation. NIL.

Question Number. 5. 1 calorie is equal to.

Option A. 4 J.

Option B. 40 J.

Option C. 400 J.

Correct Answer is. 4 J.

Explanation. NIL.

Question Number. 6. 1 BTU equals.

Option A. 1055 Joules.

Option B. 1055 Calorie.

Option C. 1055 kJ.

Correct Answer is. 1055 Joules.

Explanation. NIL.

Question Number. 7. Temperature is a measure of.

Option A. the amount of friction produced by two mating surfaces.

Option B. the amount of vibration of molecules.

Option C. the heat energy of particles.

Correct Answer is. the amount of vibration of molecules.

Explanation. Heat energy applied to an object does not necessarily increase temperature (eg. when melting or evaporating).

Question Number. 8. What temperature scale is used with the combined gas law?.

Option A. Absolute.

Option B. Fahrenheit.

Option C. Celsius.

Correct Answer is. Absolute.

Explanation. Kelvin (absolute scale) is always used with the combined gas law equation.";.

Question Number. 9. What is 1 btu/lb in joules per kilogram?.

Option A. 2326 j/kg.

Option B. 4128 j/kg.

Option C. 9.18 j/kg.

Correct Answer is. 2326 j/kg.

Explanation. This is referring to specific energy content (J/kg or Btu/lb) of fuel. 1 btu = 1055 J. 1 lb = 2.2 kg. Therefore 1 btu = 2326 J/kg.

Question Number. 10. 1 CHU = Centigrade Heat Unit = 1400 ft lbs =energy to raise.

Option A. 1 lb of water by 1 °F.

Option B. 1 kg of water by 1 °C.

Option C. 1 lb of water by 1 °C.

Correct Answer is. 1 lb of water by 1 °C.

Explanation. 1 CHU is the heat required to raise 1 lb of water 1 degree Centigrade (=1.8 BTU).

Question Number. 11. 1 BTU = 778 ft lbs which is the energy required to raise the temperature of.

Option A. 1 lb of water by 1 °F.

Option B. 1 kg of water by 1 °F.

Option C. 1 lb of water by 1 °C.

Correct Answer is. 1 lb of water by 1 °F.

Explanation. 1 BTU is the heat required to raise 1 lb of water 1 degree Fahrenheit.

Question Number. 12. A temperature of 41 degrees Fahrenheit is, in Centigrade.

Option A. 9 degrees.

Option B. 5 degrees.

Option C. 7 degrees.

Correct Answer is. 5 degrees.

Explanation. C = 5/9(F-32).

Question Number. 13. Heat is described as.

Option A. a high temperature.

Option B. energy in transit.

Option C. the stored energy in a hot body.

Correct Answer is. energy in transit.

Explanation. Heat is a type of transfer of energy which increases the kinetic energy of the molecules within a body.

Question Number. 14. 600K is equal to.

Option A. 853 °C.

Option B. 873 °C.

Option C. 326.85 °C.

Correct Answer is. 326.85 °C.

Explanation. Subtract 273.15.

Question Number. 15. When gases change temperature/pressure, the scale used is.

Option A. Kelvin.

Option B. degrees Fahrenheit.

Option C. degrees Centigrade.

Correct Answer is. Kelvin.

Explanation. Always use the Kelvin scale in thermodynamics.

Question Number. 16. Convert 100 °C to Kelvin.

Option A. 173 K.

Option B. 373 K.

Option C. 273 K.

Correct Answer is. 373 K.

Explanation. Degrees C to Kelvin - just add 273.

Question Number. 17. -40 °C in Fahrenheit is.

Option A. 72 °F.

Option B. 8 °F.

Option C. -40 °F.

Correct Answer is. -40 °F.

Explanation. °F = 1.8 °C + 32 1.8(-40) + 32 = -40 °F. Please do not report this as an error.

Question Number. 18. Absolute zero is.

Option A. 0 °C.

Option B. 273.15 K.

Option C. -273.15 °C.

Correct Answer is. -273.15 °C.

Explanation. Absolute zero is - 273.15 degrees Celsius.

Question Number. 19. One degree increment on the Centigrade scale is equal to what increment on the Fahrenheit scale?.

Option A. 1.8 °F.

Option B. 33 °F.

Option C. 12 °F.

Correct Answer is. 1.8 °F.

Explanation. A change of' 1 degree C. it is equal to 'a change of' 1.8 degree F.

Question Number. 20. Transfer of heat from a hot area to a cold area is.

Option A. conduction.

Option B. convection.

Option C. radiation.

Correct Answer is. conduction.

Explanation. Convection is a transfer of 'matter' from one place to another. Radiation is a system which heats up anything in its path. but heat is not 'transferred'.

Question Number. 21. Fahrenheit may be converted to Celsius by using the equation.

Option A. °C = 5/9 * ( °F - 32).

Option B. °C = 5/9 * °F - 32.

Option C. °C = 9/5 * °F + 32.

Correct Answer is. °C = 5/9 * ( °F - 32).

Explanation. °C = 5/9( °F-32). °F = 9/5 °F + 32.

Question Number. 22. What is 1 BTU/lb in joules per kilogram?.

Option A. 4128 joules per kilogram.

Option B. 9.18 joules per kilogram.

Option C. 2326 joules per kilogram.

Correct Answer is. 2326 joules per kilogram.

Explanation. 1 BTU/lb = 2326 j/kg. This is referring to heat of combustion of fuel.

Question Number. 23. Celsius to Fahrenheit is calculated by.

Option A. (9/5 * °C) + 32.

Option B. (5/9 * °C) + 32.

Option C. (5/9 + 32) + °C.

Correct Answer is. (9/5 * °C) + 32.

Explanation. Remember standard sea level temperature is 15 °C and 59F. Make °C = 15 on each formula above, and see which comes out at 59 °F".

Question Number. 24. The percentage of nitrogen in air is approximately.

Option A. 0.62.

Option B. 0.21.

Option C. 0.78.

Correct Answer is. 0.78.

Explanation. NIL.

Question Number. 25. When a system undergoes a complete cycle where the net heat supplied is equal to work done plus a change in internal energy - this is known as.

Option A. 2nd Law of thermodynamics.

Option B. First law of thermodynamics.

Option C. Ideal Gas law.

Correct Answer is. First law of thermodynamics.

Explanation. NIL.

Question Number. 26. In a heat pump.

Option A. the evaporator gains heat during the heating cycle.

Option B. the condenser always loses heat.

Option C. the pump operates in both directions.

Correct Answer is. the pump operates in both directions.

Explanation. NIL.

Question Number. 27. What is -28 °C on the Kelvin scale?.

Option A. 245 K.

Option B. 18 K.

Option C. 291 K.

Correct Answer is. 245 K.

Explanation. -28 + 273 = 245.

Question Number. 28. When water freezes, heat energy is.

Option A. absorbed.

Option B. retained.

Option C. released.

Correct Answer is. released.

Explanation. Freezing is 'exothermic'.

Question Number. 29. 842 degrees Fahrenheit is equal to.

Option A. 450 Degrees Celsius.

Option B. 400 Degrees Celsius.

Option C. 232.2 degrees Celsius.

Correct Answer is. 450 Degrees Celsius.

Explanation. C = 5/9(F - 32).

Question Number. 30. For a fixed mass of water at sea level ISA conditions and at 10,000ft.

Option A. the water will boil at a lower temperature than sea level.

Option B. the water will boil at the same temperature as sea level.

Option C. the water will boil at a higher temperature than sea level.

Correct Answer is. the water will boil at a lower temperature than sea level.

Explanation. As pressure drops, so does the boiling temperature.

Question Number. 31. Dew point is.

Option A. the temperature at which condensation actually occurs.

Option B. the temperature below which condensation occurs.

Option C. the temperature above which condensation occurs.

Correct Answer is. the temperature below which condensation occurs.

Explanation. NIL.

Question Number. 32. By adding impurities to water.

Option A. the melting point will increase and the boiling point decrease.

Option B. there will be no effect to the melting and boiling points.

Option C. the melting point will decrease and the boiling point will increase.

Correct Answer is. the melting point will decrease and the boiling point will increase.

Explanation. NIL.

Question Number. 33. Which type of circuit is used when the temperature of the source has insufficient heat for thermocouple application?.

Option A. thermistor.

Option B. temperature bulb.

Option C. balanced bridge.

Correct Answer is. thermistor.

Explanation. NIL.

Question Number. 34. Four pounds of gas at a temperature of 17 °C is heated to 89 °C. The specific heat at constant pressure and constant volume are 0.2404 and 0.1718 respectively. Find the heat absorbed by the gas at constant pressure and at constant volume.

Option A. 70.1 C.H.U. and 50 C.H.U.

Option B. 49.5 C.H.U. and 69 C.H.U.

Option C. 69.2 C.H.U. and 49.5 C.H.U.

Correct Answer is. 69.2 C.H.U. and 49.5 C.H.U.

Explanation. Q = mC(T2 -T1), 4 * 0.2404 * 72 = 69.2 CHU, and 4 * 0.1718 * 72 = 49.5 CHU.

Question Number. 35. In 'standard conditions' what is the standard for measurement of volume and density of a gas?.

Option A. 0 °C and 760mm of Mercury.

Option B. 20 °C and 700mm of Mercury.

Option C. 20 °C and 760mm of Mercury.

Correct Answer is. 0 °C and 760mm of Mercury.

Explanation. STP also applies to solids and liquids.

Question Number. 36. In 'standard conditions' what is the standard for measurement of volume and density of a liquid or solid?.

Option A. 20 °C and 760mm of Mercury.

Option B. 0 °C and 760mm of Mercury.

Option C. 20 °C and 700mm of Mercury.

Correct Answer is. 0 °C and 760mm of Mercury.

Explanation. NIL.

Question Number. 37. 842 Degrees Fahrenheit is equal to.

Option A. 450 Degrees Celsius.

Option B. 232.2 Degrees Celsius.

Option C. 400 Degrees Celsius.

Correct Answer is. 450 Degrees Celsius.

Explanation. NIL.

Question Number. 38. Which of the following 2 points are equal?.

Option A. -32 °C and 0 °F.

Option B. 40 °C and 40 °F.

Option C. -40 °C and -40 °F.

Correct Answer is. -40 °C and -40 °F.

Explanation. NIL.

Question Number. 39. What is 100 Degrees Centigrade in Fahrenheit?.

Option A. 30 Degrees.

Option B. 148 Degrees.

Option C. 212 Degrees.

Correct Answer is. 212 Degrees.

Explanation. NIL.

Question Number. 40. The absolute temperature scale that has the same increments as the Fahrenheit scale is the.

Option A. Rankin scale.

Option B. Kelvin scale.

Option C. Celsius scale.

Correct Answer is. Rankin scale.

Explanation. NIL.

Question Number. 41. The absolute temperature scale that has the same increments as the Celsius scale is the.

Option A. Rankin scale.

Option B. Kelvin scale.

Option C. Fahrenheit scale.

Correct Answer is. Kelvin scale.

Explanation. NIL.