Laws of Thermodynamics Quizzes - Test Your Understanding

Question 1

The entropy of a system undergoing an irreversible process always:

Accepted Answer

Increases.

Answer

Decreases.

Answer

Remains constant.

Answer

Can either increase or decrease.

Question 2

An ideal gas is characterized by:

Accepted Answer

Particles with negligible volume and no interactions.

Answer

Particles with significant volume and strong interactions.

Answer

Particles with negligible volume but strong interactions.

Answer

Particles with significant volume and negligible interactions.

Question 3

The specific heat of a substance is:

Accepted Answer

The amount of heat required to raise the temperature of one unit mass of the substance by one unit of temperature.

Answer

The amount of heat released when one unit mass of the substance cools by one unit of temperature.

Answer

The rate at which heat flows through a substance.

Answer

The temperature difference between a substance and its surroundings.

Question 4

Which of the following is an example of a reversible process?

Accepted Answer

Adiabatic expansion of an ideal gas.

Answer

Isothermal compression of a real gas.

Answer

Heat transfer from a hot reservoir to a cold reservoir.

Answer

Friction between two surfaces.

Question 5

The change in entropy during a spontaneous process is:

Accepted Answer

Positive.

Answer

Negative.

Answer

Zero.

Answer

Dependent on the specific process.

Question 6

Which of the following is a dimensionless quantity?

Accepted Answer

Temperature (in Kelvin).

Answer

Pressure.

Answer

Volume.

Answer

Energy.

Question 7

The entropy of a system serves as a measure of its:

Accepted Answer

Degree of disorder

Answer

Energy content

Answer

Temperature

Answer

Volume

Question 8

The second law of thermodynamics postulates that within an isolated system, the overall entropy tends to:

Accepted Answer

Increase over time

Answer

Decrease over time

Answer

Remain constant over time

Answer

Become negative

Question 9

The primary function of a heat engine is to:

Accepted Answer

Convert heat into work

Answer

Convert work into heat

Answer

Increase the entropy of the surroundings

Answer

Decrease the entropy of the surroundings

Question 10

The efficiency of a heat engine can be defined as the:

Accepted Answer

Ratio of work output to heat input

Answer

Ratio of heat output to work input

Answer

Ratio of change in entropy to heat input

Answer

Ratio of change in entropy to work input

Question 11

A refrigerator functions by:

Accepted Answer

Transferring heat from a hot reservoir to a cold reservoir

Answer

Transferring heat from a cold reservoir to a hot reservoir

Answer

Increasing the entropy of the surroundings

Answer

Decreasing the entropy of the surroundings

Question 12

The coefficient of performance of a refrigerator is defined as the:

Accepted Answer

Ratio of heat removed from the cold reservoir to work input

Answer

Ratio of work input to heat removed from the cold reservoir

Answer

Ratio of change in entropy to heat input

Answer

Ratio of change in entropy to work input

Question 13

A thermodynamic system is referred to as adiabatic if it:

Accepted Answer

Does not allow heat to enter or exit

Answer

Prevents work from being done on or by the system

Answer

Is in thermal equilibrium with its environment

Answer

Undergoes a reversible process

Question 14

Which of the following statements accurately reflects a consequence of the First Law of Thermodynamics?

Accepted Answer

The energy of an isolated system remains constant.

Answer

Energy can spontaneously be created.

Answer

Heat can spontaneously flow from a colder to a hotter object without additional energy input.

Answer

The internal energy of a system cannot be changed.

Question 15

Which thermodynamic process is defined by constant entropy?

Accepted Answer

Isentropic

Answer

Adiabatic

Answer

Isothermal

Answer

Isobarik

Question 16

Which gas property is directly proportional to its ability to perform work?

Accepted Answer

Pressure

Answer

Temperature

Answer

Volume

Answer

Entropy

Question 17

The change in internal energy of an ideal gas undergoing an isobaric process is calculated as:

Accepted Answer

Cp * (T2 - T1)

Answer

Cv * (T2 - T1)

Answer

Cv * (P2 - P1)

Answer

Cp * (P2 - P1)

Question 18

Which of the following is NOT a thermodynamic property?

Accepted Answer

Work

Answer

Volume

Answer

Entropy

Answer

Temperature

Question 19

Which law of thermodynamics describes the natural flow of heat from hotter to colder objects?

Accepted Answer

Second Law of Thermodynamics

Answer

First Law of Thermodynamics

Answer

Third Law of Thermodynamics

Question 20

Which mathematical equation accurately represents the first law of thermodynamics?

Accepted Answer

dU = dQ + dW

Answer

dU = TdS + PdV

Answer

dQ = TdS - PdV

Answer

dH = TdS - VdP

Question 21

During an isobaric process, which property remains constant?

Accepted Answer

Pressure

Answer

Volume

Answer

Temperature

Answer

Internal energy

Question 22

For a reversible process, what is the change in entropy?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Dependent on temperature

Question 23

What is the theoretical efficiency limit of a Carnot engine?

Accepted Answer

1 - Tcold/Thot

Answer

Thot - Tcold/Tcold

Answer

Tcold - Thot/Thot

Answer

Thot/Tcold - 1

Question 24

Which consequence is a direct result of the third law of thermodynamics?

Accepted Answer

The entropy of a perfect crystal at absolute zero is zero.

Answer

It is impossible to achieve temperatures below absolute zero.

Answer

At absolute zero, all substances have the same entropy.

Answer

Heat always flows from hotter to colder reservoirs.

Question 25

According to the Second Law of Thermodynamics, what happens to the entropy of an isolated system?

Accepted Answer

It always increases.

Answer

It can increase or decrease.

Answer

It remains constant.

Answer

It always decreases.

Question 26

In a closed system, energy can be transferred in which two forms?

Accepted Answer

Heat and work

Answer

Heat and mass

Answer

Work and mass

Answer

Mass and force

Question 27

What is the change in enthalpy of a system equal to?

Accepted Answer

Heat absorbed at constant pressure

Answer

Heat absorbed at constant volume

Answer

Work done on the system

Answer

Internal energy change

Question 28

What is the maximum possible efficiency for a heat engine operating between two reservoirs at different temperatures called?

Accepted Answer

Carnot efficiency

Answer

Otto efficiency

Answer

Brayton efficiency

Answer

Stirling efficiency

Question 29

How is the specific heat capacity at constant volume defined?

Accepted Answer

(∂U/∂T)V

Answer

(∂Q/∂T)V

Answer

(∂H/∂T)V

Answer

(∂S/∂T)V

Question 30

According to the Third Law of Thermodynamics, what is the entropy of a perfect crystalline solid at absolute zero?

Accepted Answer

Zero

Answer

Equal to its temperature

Answer

Equal to its enthalpy

Answer

Infinite

Question 31

In an isothermal process, where temperature remains constant, what occurs to the internal energy of the system?

Accepted Answer

Stays the same

Answer

Increases

Answer

Decreases

Question 32

Which of the following accurately states the First Law of Thermodynamics?

Accepted Answer

Energy cannot be created or destroyed but can be transferred or transformed.

Answer

Heat always flows from hotter to colder objects.

Answer

The total entropy of an isolated system always increases.

Answer

The temperature of a system is proportional to its potential energy.

Question 33

In a reversible process, what happens to the change in entropy?

Accepted Answer

It is always zero.

Answer

It is always positive.

Answer

It is always negative.

Answer

It depends on the specific process.

Question 34

Which of the following systems is considered closed?

Accepted Answer

A sealed container of gas

Answer

A piston-cylinder system with a fixed piston

Answer

A room with an open door

Answer

A bicycle pump with an open valve

Question 35

Which statement represents the Clausius formulation of the Second Law of Thermodynamics?

Accepted Answer

Heat cannot flow spontaneously from a cold reservoir to a hot reservoir.

Answer

The total entropy of an isolated system always decreases.

Answer

No process is perfectly efficient.

Answer

The temperature of a system is proportional to its internal energy.

Question 36

What is a defining characteristic of a Carnot heat engine?

Accepted Answer

It has the highest possible efficiency.

Answer

It operates irreversibly.

Answer

It converts all heat input into work.

Answer

Its cycle time is independent of temperature.

Question 37

What is the enthalpy of formation of a compound?

Accepted Answer

The heat released or absorbed when one mole of the compound is formed from its elements under standard conditions.

Answer

The internal energy of the compound at standard conditions.

Answer

The entropy of the compound at standard conditions.

Answer

The Gibbs free energy of the compound at standard conditions.

Question 38

Which of the following is NOT a consequence of the Second Law of Thermodynamics?

Accepted Answer

All processes in nature are reversible.

Answer

Entropy increases in all natural processes.

Answer

Heat cannot flow spontaneously from a cold to a hot body.

Answer

No heat engine can be 100% efficient.

Question 39

What is the relationship between temperature and the average kinetic energy of molecules?

Accepted Answer

Temperature is directly proportional to the average kinetic energy of molecules.

Answer

Temperature is inversely proportional to the average kinetic energy of molecules.

Answer

Temperature is independent of the average kinetic energy of molecules.

Answer

Temperature is inversely proportional to the square of the average kinetic energy of molecules.

Question 40

Consider a closed system undergoing an isothermal reversible process. What is true about the entropy change of the system?

Accepted Answer

It remains constant.

Answer

It cannot be determined without additional information.

Answer

It increases.

Answer

It decreases.

Question 41

Which of the following statements about the first law of thermodynamics is accurate?

Accepted Answer

Energy cannot be created or destroyed, only transferred or transformed.

Answer

Energy can be both created and destroyed.

Answer

Energy can be created but not destroyed.

Answer

Energy can be destroyed but not created.

Question 42

A closed system undergoes an adiabatic process. Which of the following is true?

Accepted Answer

There is no heat transfer between the system and the surroundings.

Answer

The temperature of the system increases.

Answer

The pressure of the system decreases.

Answer

The volume of the system remains constant.

Question 43

Entropy is a measure of a system's:

Accepted Answer

Disorder or randomness.

Answer

Temperature.

Answer

Volume.

Answer

Pressure.

Question 44

Which of the following is NOT a consequence of the second law of thermodynamics?

Accepted Answer

Heat can spontaneously flow from a colder object to a hotter object.

Answer

No process can be 100% efficient.

Answer

Entropy increases or remains constant in isolated systems.

Question 45

A heat pump operates by moving heat from a colder reservoir to a warmer reservoir. Which of the following is true?

Accepted Answer

It requires an external energy input to operate.

Answer

It can only operate at low temperatures.

Answer

It can operate without an external energy input.

Answer

It is 100% efficient.

Question 46

The SI unit of entropy is:

Accepted Answer

Joule per Kelvin.

Answer

Joule.

Answer

Kelvin.

Answer

Watt.

Question 47

Which of the following statements accurately reflects the first law of thermodynamics?

Accepted Answer

The change in internal energy of a system is equal to the heat added to the system plus the work done on the system

Answer

Energy can be created but cannot be destroyed

Answer

Entropy decreases in spontaneous processes

Answer

Heat flows spontaneously from hotter to colder bodies

Question 48

The efficiency of a Carnot cycle operating between two reservoirs at different temperatures is:

Accepted Answer

Always less than 100%

Answer

Equal to 100% if the temperature difference is small

Answer

Equal to 100% if the temperature difference is large

Answer

Greater than 100%

Question 49

A process in which the system returns to its initial state without leaving any changes in its surroundings is known as a:

Accepted Answer

Reversible process

Answer

Adiabatic process

Answer

Cyclic process

Answer

Irreversible process

Question 50

The measure of the randomness or disorder within a system is termed as:

Accepted Answer

Entropy

Answer

Gibbs free energy

Answer

Internal energy

Answer

Enthalpy

Question 51

Which of the following is NOT a thermodynamic property?

Accepted Answer

Force

Answer

Volume

Answer

Temperature

Answer

Pressure

Question 52

When heat is added to a system and it expands, the change in its internal energy is:

Accepted Answer

Positive

Answer

Negative

Answer

Cannot be determined

Answer

Zero