Ramsay Test Thermodynamics 3 — Questions and Answers
Question 1: The second law of thermodynamics states that the entropy of an isolated system tends to do what?
- Increase (Correct answer)
- Decrease
- Remain constant
- Reach zero
Correct answer: Increase
Total entropy of an isolated system always increases over time in real processes.
Question 2: In a refrigeration cycle, what does the evaporator do?
- Absorbs heat from the cooled space (Correct answer)
- Rejects heat to the surroundings
- Compresses the refrigerant
- Expands the liquid refrigerant
Correct answer: Absorbs heat from the cooled space
The evaporator absorbs heat from the interior as the refrigerant evaporates.
Question 3: What property describes a material's resistance to heat flow?
- Thermal resistance (Correct answer)
- Thermal conductivity
- Heat capacity
- Emissivity
Correct answer: Thermal resistance
Thermal resistance (R-value) measures how well a material resists heat transfer.
Question 4: When a gas is compressed quickly with no heat exchange, the process is called what?
- Adiabatic (Correct answer)
- Isothermal
- Isobaric
- Isochoric
Correct answer: Adiabatic
An adiabatic process occurs with no heat transfer to or from the system.
Question 5: What is the SI unit of heat energy?
- Joule (Correct answer)
- Watt
- Pascal
- Newton
Correct answer: Joule
The joule is the SI unit for energy, including heat.
Question 6: Hot air rising and cool air sinking in a room is an example of what heat transfer mode?
- Convection (Correct answer)
- Conduction
- Radiation
- Sublimation
Correct answer: Convection
Convection moves heat through the bulk motion of a fluid such as air.
Question 7: What is specific heat capacity a measure of?
- Energy to raise one unit mass by one degree (Correct answer)
- Total heat in a body
- Rate of heat flow
- Temperature at phase change
Correct answer: Energy to raise one unit mass by one degree
Specific heat capacity is the energy needed to raise one kilogram by one degree.
Ramsay Test Thermodynamics 3
The second law of thermodynamics states that the entropy of an isolated system tends to do what?