Thermodynamics MCQ Quiz - Objective Question with Answer for Thermodynamics - Download Free PDF
Last updated on Jun 10, 2025
Latest Thermodynamics MCQ Objective Questions
Thermodynamics Question 1:
Zeroth law of thermodynamics is related to:
Answer (Detailed Solution Below)
Thermodynamics Question 1 Detailed Solution
CONCEPT:
Zeroth Law of Thermodynamics
- The Zeroth Law of Thermodynamics deals with the concept of thermal equilibrium.
- It states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
- This law forms the basis for the definition of temperature.
- It implies that temperature is the property that determines whether a system is in thermal equilibrium or not.
EXPLANATION
- The Zeroth Law provides the foundation for the measurement of temperature.
- It allows us to use a thermometer as the third system to measure the temperature of other systems.
- Temperature: This is the correct answer, as the Zeroth Law establishes the concept of temperature as a measurable property.
Therefore, the correct answer is Temperature.
Thermodynamics Question 2:
ΔQ = ΔU + ΔW is equation for ___________
Answer (Detailed Solution Below)
Thermodynamics Question 2 Detailed Solution
The correct answer is First Law of Thermodynamics.
Key Points
- The First Law of Thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic processes.
- It states that energy cannot be created or destroyed in an isolated system.
- The change in the internal energy of a system (ΔU) is equal to the heat added to the system (ΔQ) minus the work done by the system on its surroundings (ΔW).
- This can be mathematically expressed as ΔQ = ΔU + ΔW.
Additional Information
- Internal Energy (U)
- It is the total energy contained within a system, including kinetic and potential energy at the molecular level.
- Changes in internal energy can result from heat transfer or work done.
- Heat (Q)
- It is a form of energy transfer between systems due to a temperature difference.
- Heat transfer can occur through conduction, convection, or radiation.
- Work (W)
- In thermodynamics, work is the energy transferred when an object is moved by a force.
- Positive work is done by the system when it expands against an external pressure.
- Applications of the First Law
- It is used to analyze various thermodynamic cycles such as the Carnot cycle, Otto cycle, and refrigeration cycles.
- It helps in understanding the energy efficiency of engines and other systems.
- Limitations
- The First Law does not provide information about the direction of processes or the feasibility of reactions.
- It does not explain entropy changes or the Second Law of Thermodynamics.
Thermodynamics Question 3:
Zeroth Law leads to the concept of ______
Answer (Detailed Solution Below)
Thermodynamics Question 3 Detailed Solution
The correct answer is Temperature.
Key Points
- The Zeroth Law of Thermodynamics states that if two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other.
- This law establishes the concept of temperature as a measurable and comparable quantity.
- The Zeroth Law allows for the construction of thermometers to measure temperature based on the principle of thermal equilibrium.
- Temperature is a scalar quantity that indicates the degree of hotness or coldness of a body or environment.
- It is critical for defining the state of a system in thermodynamics and is key to understanding energy transfer processes like heat.
Additional Information
- Thermal Equilibrium:
- Two systems are in thermal equilibrium if there is no net flow of thermal energy between them.
- It is a foundational concept in thermodynamics and a prerequisite for measuring temperature accurately.
- Thermometers:
- Devices used to measure temperature based on physical properties like expansion of mercury or electrical resistance.
- They rely on the Zeroth Law to ensure consistent and accurate readings.
- Temperature Scales:
- Common scales include Celsius, Fahrenheit, and Kelvin.
- Kelvin is the SI unit of temperature and starts from absolute zero, the lowest theoretically possible temperature.
- Thermodynamics:
- A branch of physics that deals with the relationships between heat, work, and energy.
- The Zeroth Law complements the First, Second, and Third Laws of Thermodynamics in understanding energy systems.
Thermodynamics Question 4:
___ is zero for a cyclic process.
Answer (Detailed Solution Below)
Thermodynamics Question 4 Detailed Solution
The correct answer is ∆U.
Key Points
- In a cyclic process, the system returns to its initial state after completing the cycle, meaning the change in internal energy (∆U) is zero.
- Internal energy (U) is a state function, and its value depends only on the state of the system, not on the path taken to reach that state.
- The first law of thermodynamics states: ∆U = Q - W, where Q is heat added to the system, and W is work done by the system.
- For a cyclic process, the initial and final states are the same, so the net internal energy change (∆U) is zero, regardless of the values of Q and W.
- Examples of cyclic processes include Carnot cycles, Otto cycles, and Rankine cycles commonly used in thermodynamics and heat engines.
Additional Information
- Cyclic Process
- A thermodynamic process where the system undergoes changes but eventually returns to its initial state.
- Examples include processes in heat engines, refrigeration cycles, and power plants.
- Internal Energy (U)
- The total energy contained within a system, including kinetic and potential energy at the molecular level.
- It is a state function and depends only on the current state of the system (temperature, pressure, volume).
- First Law of Thermodynamics
- Expresses the principle of conservation of energy: energy cannot be created or destroyed; it can only change forms.
- Mathematically: ∆U = Q - W, where Q is the heat added to the system, and W is the work done by the system.
- Work (W) and Heat (Q)
- Work is the energy transferred by a system to its surroundings due to macroscopic forces.
- Heat is the energy transferred between systems due to a temperature difference.
Top Thermodynamics MCQ Objective Questions
ΔQ = ΔU + ΔW is equation for ___________
Answer (Detailed Solution Below)
Thermodynamics Question 5 Detailed Solution
Download Solution PDFThe correct answer is First Law of Thermodynamics.
Key Points
- The First Law of Thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic processes.
- It states that energy cannot be created or destroyed in an isolated system.
- The change in the internal energy of a system (ΔU) is equal to the heat added to the system (ΔQ) minus the work done by the system on its surroundings (ΔW).
- This can be mathematically expressed as ΔQ = ΔU + ΔW.
Additional Information
- Internal Energy (U)
- It is the total energy contained within a system, including kinetic and potential energy at the molecular level.
- Changes in internal energy can result from heat transfer or work done.
- Heat (Q)
- It is a form of energy transfer between systems due to a temperature difference.
- Heat transfer can occur through conduction, convection, or radiation.
- Work (W)
- In thermodynamics, work is the energy transferred when an object is moved by a force.
- Positive work is done by the system when it expands against an external pressure.
- Applications of the First Law
- It is used to analyze various thermodynamic cycles such as the Carnot cycle, Otto cycle, and refrigeration cycles.
- It helps in understanding the energy efficiency of engines and other systems.
- Limitations
- The First Law does not provide information about the direction of processes or the feasibility of reactions.
- It does not explain entropy changes or the Second Law of Thermodynamics.
Thermodynamics Question 6:
Zeroth law of thermodynamics is related to:
Answer (Detailed Solution Below)
Thermodynamics Question 6 Detailed Solution
CONCEPT:
Zeroth Law of Thermodynamics
- The Zeroth Law of Thermodynamics deals with the concept of thermal equilibrium.
- It states that if two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
- This law forms the basis for the definition of temperature.
- It implies that temperature is the property that determines whether a system is in thermal equilibrium or not.
EXPLANATION
- The Zeroth Law provides the foundation for the measurement of temperature.
- It allows us to use a thermometer as the third system to measure the temperature of other systems.
- Temperature: This is the correct answer, as the Zeroth Law establishes the concept of temperature as a measurable property.
Therefore, the correct answer is Temperature.
Thermodynamics Question 7:
ΔQ = ΔU + ΔW is equation for ___________
Answer (Detailed Solution Below)
Thermodynamics Question 7 Detailed Solution
The correct answer is First Law of Thermodynamics.
Key Points
- The First Law of Thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic processes.
- It states that energy cannot be created or destroyed in an isolated system.
- The change in the internal energy of a system (ΔU) is equal to the heat added to the system (ΔQ) minus the work done by the system on its surroundings (ΔW).
- This can be mathematically expressed as ΔQ = ΔU + ΔW.
Additional Information
- Internal Energy (U)
- It is the total energy contained within a system, including kinetic and potential energy at the molecular level.
- Changes in internal energy can result from heat transfer or work done.
- Heat (Q)
- It is a form of energy transfer between systems due to a temperature difference.
- Heat transfer can occur through conduction, convection, or radiation.
- Work (W)
- In thermodynamics, work is the energy transferred when an object is moved by a force.
- Positive work is done by the system when it expands against an external pressure.
- Applications of the First Law
- It is used to analyze various thermodynamic cycles such as the Carnot cycle, Otto cycle, and refrigeration cycles.
- It helps in understanding the energy efficiency of engines and other systems.
- Limitations
- The First Law does not provide information about the direction of processes or the feasibility of reactions.
- It does not explain entropy changes or the Second Law of Thermodynamics.
Thermodynamics Question 8:
Zeroth Law leads to the concept of ______
Answer (Detailed Solution Below)
Thermodynamics Question 8 Detailed Solution
The correct answer is Temperature.
Key Points
- The Zeroth Law of Thermodynamics states that if two systems are each in thermal equilibrium with a third system, they are in thermal equilibrium with each other.
- This law establishes the concept of temperature as a measurable and comparable quantity.
- The Zeroth Law allows for the construction of thermometers to measure temperature based on the principle of thermal equilibrium.
- Temperature is a scalar quantity that indicates the degree of hotness or coldness of a body or environment.
- It is critical for defining the state of a system in thermodynamics and is key to understanding energy transfer processes like heat.
Additional Information
- Thermal Equilibrium:
- Two systems are in thermal equilibrium if there is no net flow of thermal energy between them.
- It is a foundational concept in thermodynamics and a prerequisite for measuring temperature accurately.
- Thermometers:
- Devices used to measure temperature based on physical properties like expansion of mercury or electrical resistance.
- They rely on the Zeroth Law to ensure consistent and accurate readings.
- Temperature Scales:
- Common scales include Celsius, Fahrenheit, and Kelvin.
- Kelvin is the SI unit of temperature and starts from absolute zero, the lowest theoretically possible temperature.
- Thermodynamics:
- A branch of physics that deals with the relationships between heat, work, and energy.
- The Zeroth Law complements the First, Second, and Third Laws of Thermodynamics in understanding energy systems.
Thermodynamics Question 9:
___ is zero for a cyclic process.
Answer (Detailed Solution Below)
Thermodynamics Question 9 Detailed Solution
The correct answer is ∆U.
Key Points
- In a cyclic process, the system returns to its initial state after completing the cycle, meaning the change in internal energy (∆U) is zero.
- Internal energy (U) is a state function, and its value depends only on the state of the system, not on the path taken to reach that state.
- The first law of thermodynamics states: ∆U = Q - W, where Q is heat added to the system, and W is work done by the system.
- For a cyclic process, the initial and final states are the same, so the net internal energy change (∆U) is zero, regardless of the values of Q and W.
- Examples of cyclic processes include Carnot cycles, Otto cycles, and Rankine cycles commonly used in thermodynamics and heat engines.
Additional Information
- Cyclic Process
- A thermodynamic process where the system undergoes changes but eventually returns to its initial state.
- Examples include processes in heat engines, refrigeration cycles, and power plants.
- Internal Energy (U)
- The total energy contained within a system, including kinetic and potential energy at the molecular level.
- It is a state function and depends only on the current state of the system (temperature, pressure, volume).
- First Law of Thermodynamics
- Expresses the principle of conservation of energy: energy cannot be created or destroyed; it can only change forms.
- Mathematically: ∆U = Q - W, where Q is the heat added to the system, and W is the work done by the system.
- Work (W) and Heat (Q)
- Work is the energy transferred by a system to its surroundings due to macroscopic forces.
- Heat is the energy transferred between systems due to a temperature difference.