Thermodynamics MCQs

Question: Which law of thermodynamics states that energy cannot be created or destroyed, only transformed from one form to another?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: B) First law
Question: The SI unit of heat and energy is:

A) Joule (J)
B) Watt (W)
C) Newton (N)
D) Pascal (Pa)
Answer: A) Joule (J)
Question: The process in which no heat is exchanged with the surroundings is known as:

A) Adiabatic process
B) Isothermal process
C) Isobaric process
D) Isochoric process
Answer: A) Adiabatic process
Question: The area under the curve on a pressure-volume (PV) diagram represents:

A) Work done
B) Change in internal energy
C) Heat transferred
D) Change in entropy
Answer: A) Work done
Question: Which law of thermodynamics states that the entropy of a system tends to increase over time?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: C) Second law
Question: What is the specific heat capacity of a substance?

A) The amount of heat required to raise the temperature of 1 kg of the substance by 1 degree Celsius
B) The amount of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius
C) The temperature at which the substance boils
D) The temperature at which the substance freezes
Answer: A) The amount of heat required to raise the temperature of 1 kg of the substance by 1 degree Celsius
Question: The efficiency of a Carnot engine depends on:

A) Temperature of the hot reservoir only
B) Temperature of the cold reservoir only
C) Temperatures of both the hot and cold reservoirs
D) Pressure of the working fluid
Answer: C) Temperatures of both the hot and cold reservoirs
Question: The change in internal energy of a system is given by:

A) Q – W
B) Q + W
C) Q / W
D) Q * W
Answer: A) Q – W
Question: Which process involves constant volume?

A) Isothermal process
B) Isobaric process
C) Isochoric process
D) Adiabatic process
Answer: C) Isochoric process
Question: The process in which temperature remains constant is known as:

A) Adiabatic process
B) Isothermal process
C) Isobaric process
D) Isochoric process
Answer: B) Isothermal process
Question: The efficiency of a heat engine is always:

A) Less than 100%
B) More than 100%
C) Exactly 100%
D) Zero
Answer: A) Less than 100%
Question: What is the work done by a gas during an isothermal expansion?

A) Zero
B) Positive
C) Negative
D) Infinite
Answer: A) Zero
Question: Which of the following is a state function?

A) Heat
B) Work
C) Energy
D) Power
Answer: C) Energy
Question: What happens to the entropy of a system in an irreversible process?

A) Decreases
B) Increases
C) Remains constant
D) Becomes zero
Answer: B) Increases
Question: The temperature at which a substance changes from a liquid to a gas is called:

A) Melting point
B) Freezing point
C) Boiling point
D) Condensation point
Answer: C) Boiling point
Question: Which law of thermodynamics establishes the concept of thermal equilibrium?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: A) Zeroth law
Question: The maximum possible efficiency of a heat engine operating between two temperatures is given by:

A) Carnot efficiency
B) Kelvin efficiency
C) Boltzmann efficiency
D) Joule efficiency
Answer: A) Carnot efficiency
Question: What is the work done when a gas expands isothermally according to the ideal gas law?

A) W = PΔV
B) W = nRT
C) W = Q
D) W = PV
Answer: D) W = PV
Question: Entropy is a measure of:

A) Disorder in a system
B) Order in a system
C) Energy in a system
D) Temperature in a system
Answer: A) Disorder in a system
Question: The specific heat capacity of water is highest when compared to other common substances. This property is due to:

A) Its high boiling point
B) Its low melting point
C) Its hydrogen bonding
D) Its low density
Answer: C) Its hydrogen bonding
Question: What is the principle behind a refrigerator?

A) Heat flows naturally from a hot object to a cold object
B) Heat flows naturally from a cold object to a hot object
C) Work is done to transfer heat from a cold object to a hot object
D) Work is done to transfer heat from a hot object to a cold object
Answer: D) Work is done to transfer heat from a hot object to a cold object
Question: Which of the following is a correct statement about the third law of thermodynamics?

A) It defines the relationship between heat and work
B) It states that entropy approaches zero as temperature approaches absolute zero
C) It establishes the concept of thermal equilibrium
D) It states that energy cannot be created or destroyed
Answer: B) It states that entropy approaches zero as temperature approaches absolute zero
Question: What does the term “adiabatic” mean in thermodynamics?

A) No heat exchange with the surroundings
B) Constant pressure process
C) Constant volume process
D) Constant temperature process
Answer: A) No heat exchange with the surroundings
Question: In a reversible process, the change in entropy of the universe is:

A) Zero
B) Positive
C) Negative
D) Undefined
Answer: A) Zero
Question: The heat capacity of an object depends on:

A) Its mass and temperature
B) Its volume and pressure
C) Its density and shape
D) Its color and texture
Answer: A) Its mass and temperature
Question: What is the efficiency of a Carnot engine operating between two reservoirs at temperatures Th (hot) and Tc (cold)?

A) (Th – Tc) / Th
B) (Th – Tc) / Tc
C) Th / (Th – Tc)
D) Tc / (Th – Tc)
Answer: B) (Th – Tc) / Th
Question: The internal energy of a system is:

A) The sum of its kinetic and potential energies
B) The heat content of the system
C) The work done by the system
D) The heat absorbed by the surroundings
Answer: A) The sum of its kinetic and potential energies
Question: Which law of thermodynamics deals with the concept of absolute zero?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: D) Third law
Question: The process in which pressure remains constant is known as:

A) Isothermal process
B) Isobaric process
C) Isochoric process
D) Adiabatic process
Answer: B) Isobaric process
Question: The efficiency of a heat engine is given by:

A) (Qh – Qc) / Qh
B) (Qh – Qc) / Qc
C) Qh / (Qh – Qc)
D) Qc / (Qh – Qc)
Answer: D) Qc / (Qh – Qc)
Question: Which law of thermodynamics states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: A) Zeroth law
Question: The change in entropy of a system is given by:

A) ΔS = Q / T
B) ΔS = T / Q
C) ΔS = Q * T
D) ΔS = Q – T
Answer: A) ΔS = Q / T
Question: What does the term “enthalpy” represent in thermodynamics?

A) The internal energy of a system
B) The heat content of a system at constant pressure
C) The work done by a system
D) The heat absorbed by the surroundings
Answer: B) The heat content of a system at constant pressure
Question: Which law of thermodynamics deals with the conservation of energy?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: B) First law
Question: The temperature at which a substance changes from a solid to a liquid is called:

A) Melting point
B) Freezing point
C) Boiling point
D) Condensation point
Answer: A) Melting point
Question: What is the principle behind a heat pump?

A) Heat flows naturally from a hot object to a cold object
B) Heat flows naturally from a cold object to a hot object
C) Work is done to transfer heat from a cold object to a hot object
D) Work is done to transfer heat from a hot object to a cold object
Answer: C) Work is done to transfer heat from a cold object to a hot object
Question: The process in which volume remains constant is known as:

A) Isothermal process
B) Isobaric process
C) Isochoric process
D) Adiabatic process
Answer: C) Isochoric process
Question: The total energy of an isolated system is constant according to which law of thermodynamics?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: B) First law
Question: Which statement about the second law of thermodynamics is correct?

A) It states that heat always flows from a cold object to a hot object
B) It states that energy cannot be created or destroyed
C) It states that entropy of an isolated system increases over time
D) It states that the internal energy of a system is constant
Answer: C) It states that entropy of an isolated system increases over time
Question: The specific heat capacity of a substance depends on:

A) Its mass and temperature change
B) Its volume and pressure change
C) Its density and shape
D) Its color and texture
Answer: A) Its mass and temperature change
Question: The efficiency of a Carnot engine operating between two temperatures T1 and T2 is maximum when:

A) T1 = T2
B) T1 > T2
C) T1 < T2
D) T1 = 0 K
Answer: A) T1 = T2
Question: The heat capacity of an object is defined as:

A) The heat required to raise its temperature by 1 degree Celsius
B) The work done by the object when heated
C) The temperature change of the object due to heat
D) The heat released by the object when cooled
Answer: A) The heat required to raise its temperature by 1 degree Celsius
Question: What is the difference between heat and temperature?

A) Heat is a measure of thermal energy, while temperature is a measure of the average kinetic energy of particles
B) Heat is a measure of temperature, while temperature is a measure of thermal energy
C) Heat is a scalar quantity, while temperature is a vector quantity
D) Heat is an extensive property, while temperature is an intensive property
Answer: A) Heat is a measure of thermal energy, while temperature is a measure of the average kinetic energy of particles
Question: What is the relationship between heat and work in thermodynamics?

A) Heat and work are interchangeable forms of energy
B) Heat is a form of energy, while work is not
C) Work is a form of energy, while heat is not
D) Heat and work are unrelated concepts in thermodynamics
Answer: A) Heat and work are interchangeable forms of energy
Question: What does the term “adiabatic” mean in thermodynamics?

A) No heat exchange with the surroundings
B) Constant pressure process
C) Constant volume process
D) Constant temperature process
Answer: A) No heat exchange with the surroundings
Question: The process in which pressure remains constant is known as:

A) Isothermal process
B) Isobaric process
C) Isochoric process
D) Adiabatic process
Answer: B) Isobaric process
Question: The efficiency of a heat engine is given by:

A) (Qh – Qc) / Qh
B) (Qh – Qc) / Qc
C) Qh / (Qh – Qc)
D) Qc / (Qh – Qc)
Answer: D) Qc / (Qh – Qc)
Question: Which law of thermodynamics deals with the concept of absolute zero?

A) Zeroth law
B) First law
C) Second law
D) Third law
Answer: D) Third law
Question: The temperature at which a substance changes from a solid to a liquid is called:

A) Melting point
B) Freezing point
C) Boiling point
D) Condensation point
Answer: A) Melting point
Question: What is the principle behind a heat pump?

A) Heat flows naturally from a hot object to a cold object
B) Heat flows naturally from a cold object to a hot object
C) Work is done to transfer heat from a cold object to a hot object
D) Work is done to transfer heat from a hot object to a cold object
Answer: C) Work is done to transfer heat from a cold object to a hot object

Thermodynamics MCQs

More MCQs on Avionics Engineering MCQs

Leave a Comment Cancel reply