Introduction to Thermodynamics: Master the Basics of Energy and Heat Transfer

Question 1

Which of the following is NOT a fundamental law of thermodynamics?

Accepted Answer

Carnot law

Answer

Zeroth law

Answer

First law

Answer

Second law

Question 2

The process in which the entropy of an isolated system increases is called:

Accepted Answer

Irreversible

Answer

Isothermal

Answer

Adiabatic

Answer

Isochoric

Question 3

Which of the following is a type of thermodynamic system that allows for exchange of both energy and mass?

Accepted Answer

Open

Answer

Isolated

Answer

Closed

Answer

Adiabatic

Question 4

The efficiency of a heat engine is defined as the ratio of:

Accepted Answer

Net work output to heat input

Answer

Heat input to net work output

Answer

Temperature change to entropy change

Answer

Internal energy change to external work

Question 5

Which of the following equations represents the first law of thermodynamics?

Accepted Answer

dU = dQ - dW

Answer

dS = dQ/T

Answer

PV = nRT

Answer

Cp - Cv = R

Question 6

Which of the following processes is characterized by constant volume?

Accepted Answer

Isochoric

Answer

Isothermal

Answer

Adiabatic

Answer

Isobaric

Question 7

The critical point of a substance is the point at which:

Accepted Answer

Liquid and gas phases become indistinguishable

Answer

Solid and liquid phases become indistinguishable

Answer

Gas and plasma phases become indistinguishable

Answer

Solid, liquid, and gas phases coexist in equilibrium

Question 8

The third law of thermodynamics implies that:

Accepted Answer

Entropy of a perfect crystal is zero at absolute zero

Answer

Entropy of a system always increases

Answer

Heat cannot flow spontaneously from a colder to a hotter body

Answer

The volume of an ideal gas is zero at absolute zero

Question 9

What is entropy?

Accepted Answer

A measure of the disorder of a system.

Answer

The total amount of energy in a system.

Answer

The rate of change of temperature in a system.

Answer

The force acting on a system.

Question 10

Which law of thermodynamics states that energy cannot be created or destroyed?

Accepted Answer

First law

Answer

Zeroth law

Answer

Second law

Answer

Third law

Question 11

Which of the following is NOT a mechanism of heat transfer?

Accepted Answer

Adiabatic transfer

Answer

Conduction

Answer

Convection

Answer

Radiation

Question 12

The ideal gas law, also known as the perfect gas equation, is given by:

Accepted Answer

PV = nRT

Answer

PV = nRT^2

Answer

PV = RT

Answer

PV² = RT

Question 13

According to the first law of thermodynamics, which of the following statements is true?

Accepted Answer

Energy can neither be created nor destroyed, but it can be transferred.

Answer

Entropy always increases in an isolated system.

Answer

The work done by a system is always equal to the heat it absorbs.

Answer

Heat flows from cold to hot.

Question 14

Entropy is defined as a measure of:

Accepted Answer

The randomness or disorder within a system.

Answer

The amount of heat a system contains.

Answer

The temperature of a system relative to its surroundings.

Answer

The potential of a system to perform work.

Question 15

Which of the following processes is considered isentropic?

Accepted Answer

An adiabatic and reversible compression.

Answer

An isothermal and irreversible expansion.

Answer

An isobaric and irreversible cooling.

Answer

A spontaneous and irreversible heat transfer.

Question 16

Heat and work differ primarily in that:

Accepted Answer

Heat is a form of energy transfer due to a temperature difference, while work is a form of energy transfer due to a force acting through a distance.

Answer

Heat is a form of energy storage, while work is a form of energy transfer.

Answer

Heat can only be transferred from hot to cold, while work can be transferred in either direction.

Answer

Work can be converted to heat, but heat cannot be converted to work.

Question 17

The efficiency of a heat engine is calculated as:

Accepted Answer

The ratio of work output to heat input.

Answer

The ratio of heat output to work input.

Answer

The ratio of work input to heat output.

Answer

The ratio of heat input to work output.

Question 18

A thermodynamic system can be defined as:

Accepted Answer

A combination of matter and space under investigation.

Answer

A collection of matter under investigation.

Answer

A specific region of space under investigation.

Answer

A force acting on a body under investigation.

Question 19

The zeroth law of thermodynamics states that:

Accepted Answer

If two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other.

Answer

Entropy always tends to increase in an isolated system.

Answer

Energy cannot be created or destroyed.

Answer

Heat naturally flows from hot to cold.

Question 20

A closed system is characterized by:

Accepted Answer

The ability to exchange energy but not matter with its surroundings.

Answer

The ability to exchange both energy and matter with its surroundings.

Answer

The inability to exchange either energy or matter with its surroundings.

Answer

The ability to exchange matter but not energy with its surroundings.

Question 21

What is thermodynamic equilibrium and why is it important in understanding thermodynamic systems?

Accepted Answer

Thermodynamic equilibrium is a state where a system's properties (temperature, pressure, volume) remain constant over time.

Answer

Thermodynamic equilibrium is a state where a system operates at its highest efficiency.

Answer

Thermodynamic equilibrium is a state where a system is completely isolated from its surroundings.

Answer

Thermodynamic equilibrium is a state where a system is constantly changing.

Question 22

Which of the following is NOT a law of thermodynamics?

Accepted Answer

Law of Mass Conservation

Answer

First Law of Thermodynamics

Answer

Zeroth Law of Thermodynamics

Answer

Second Law of Thermodynamics

Question 23

Which thermodynamic process occurs at constant temperature?

Accepted Answer

Isothermal

Answer

Adiabatic

Answer

Isochoric

Answer

Isobaric

Question 24

According to the second law of thermodynamics, the entropy of a closed system:

Accepted Answer

Can only increase or remain constant

Answer

Is always zero

Answer

Can either increase or decrease

Answer

Must decrease over time

Question 25

Which of the following is a thermodynamic property?

Accepted Answer

Temperature

Answer

Velocity

Answer

Force

Answer

Acceleration

Question 26

The enthalpy of a system is defined as:

Accepted Answer

Internal energy + (Pressure x Volume)

Answer

Entropy x Temperature

Answer

Heat capacity x Temperature

Answer

Internal energy - (Pressure x Volume)

Question 27

Which of the following statements about Gibbs free energy is true?

Accepted Answer

It is a measure of the maximum non-expansion work that can be extracted from a thermodynamic system at constant temperature and pressure.

Answer

It is a measure of the internal energy of the system.

Answer

It is always positive.

Answer

It is equal to the change in entropy of the system.

Question 28

According to the First Law of Thermodynamics, what happens to energy in a closed system?

Accepted Answer

Energy can be transferred or transformed within the system but cannot be created or destroyed.

Answer

Energy can be created and destroyed within the system.

Answer

Energy is always conserved within the system.

Question 29

In a closed thermodynamic system, which quantity remains constant?

Accepted Answer

Total energy

Answer

Temperature

Answer

Pressure

Answer

Volume

Question 30

Which thermodynamic process occurs at constant temperature?

Accepted Answer

Isothermal

Answer

Isentropic

Answer

Isochoric

Answer

Adiabatic

Question 31

A system that has reached maximum disorder and has no available energy for work is said to be in:

Accepted Answer

Thermal equilibrium

Answer

Chemical equilibrium

Answer

Mechanical equilibrium

Answer

Phase equilibrium

Question 32

Which thermodynamic property measures the disorder within a system?

Accepted Answer

Entropy

Answer

Internal energy

Answer

Gibbs free energy

Answer

Enthalpy

Question 33

The theoretical maximum efficiency of a heat engine operating between two reservoirs at different temperatures is known as:

Accepted Answer

Carnot efficiency

Answer

Otto efficiency

Answer

Rankine efficiency

Answer

Diesel efficiency

Question 34

Which of the following is NOT an assumption of the ideal gas law?

Accepted Answer

Gas particles experience strong intermolecular forces.

Answer

Gas particles have no volume.

Answer

Gas particles collide elastically.

Answer

Gas particles move in straight lines.

Question 35

Which property of a substance quantifies its ability to resist temperature change?

Accepted Answer

Specific heat capacity

Answer

Density

Answer

Thermal conductivity

Answer

Emissivity

Question 36

A heat engine absorbs 500 kJ of heat from a high-temperature reservoir and releases 200 kJ of heat to a low-temperature reservoir. What is the thermal efficiency of this engine?

Accepted Answer

60%

Answer

40%

Answer

150%

Answer

25%

Question 37

Which thermodynamic process involves a gas expanding at a constant temperature?

Accepted Answer

Isothermal

Answer

Isobaric

Answer

Adiabatic

Answer

Isochoric

Question 38

Which of the following is NOT a characteristic of an ideal gas?

Accepted Answer

The molecules have a finite volume.

Answer

The molecules are in constant random motion.

Answer

There are no intermolecular forces.

Answer

The collisions between molecules are perfectly elastic.

Question 39

A system absorbs 100 kJ of heat and performs 50 kJ of work on its surroundings. What is the change in internal energy of the system?

Accepted Answer

50 kJ

Answer

-150 kJ

Answer

150 kJ

Answer

-50 kJ

Question 40

Two objects are in thermal equilibrium when:

Accepted Answer

They have the same temperature.

Answer

They are in thermal contact and heat is flowing between them.

Answer

One object is hotter than the other.

Answer

They have the same internal energy.

Question 41

Which of the following thermodynamic properties quantifies the degree of disorder or randomness of a system?

Accepted Answer

Entropy

Answer

Gibbs Free Energy

Answer

Internal Energy

Answer

Enthalpy

Question 42

What type of heat transfer primarily involves the movement of fluids?

Accepted Answer

Convection

Answer

Evaporation

Answer

Radiation

Answer

Conduction

Question 43

The Clausius-Clapeyron equation relates the vapor pressure of a liquid to its:

Accepted Answer

Temperature

Answer

Volume

Answer

Pressure

Answer

Entropy

Question 44

Among the following thermodynamic cycles, which one is considered the most efficient for converting heat into work?

Accepted Answer

Carnot cycle

Answer

Rankine cycle

Answer

Diesel cycle

Answer

Otto cycle

Question 45

The first law of thermodynamics is a statement of:

Accepted Answer

Energy conservation

Answer

Entropy increase

Answer

Heat transfer

Answer

Work done

Question 46

Which of the following best describes an adiabatic process?

Accepted Answer

A process where no heat is transferred between the system and its surroundings

Answer

A process where the temperature of the system remains constant

Answer

A process where the pressure of the system remains constant

Answer

A process where the volume of the system remains constant

Question 47

The efficiency of a heat engine is defined as:

Accepted Answer

The ratio of work output to heat input

Answer

The heat transfer rate

Answer

The ratio of heat input to work output

Answer

The change in internal energy of the system

Question 48

Which of the following is an example of a closed thermodynamic system?

Accepted Answer

A sealed container of gas

Answer

A system open to the atmosphere

Answer

A flowing fluid

Answer

A system in thermal equilibrium with its surroundings

Question 49

Entropy is a measure of:

Accepted Answer

The disorder or randomness of a system

Answer

The temperature of a system

Answer

The volume of a system

Answer

The energy of a system

Question 50

Which of the following processes is irreversible?

Accepted Answer

Heat transfer through a finite temperature difference

Answer

Adiabatic compression

Answer

Isothermal expansion

Answer

Isochoric heating

Question 51

The Gibbs free energy is useful because it:

Accepted Answer

Provides information about the spontaneity and maximum useful work obtainable from a system

Answer

Is always positive

Answer

Can be used to calculate the entropy of a system

Answer

Is independent of temperature

Question 52

Which of the following is a characteristic of a pure substance?

Accepted Answer

A fixed melting point at a given pressure

Answer

A non-uniform composition

Answer

A variable boiling point

Answer

A changing density with temperature

Question 53

The critical point of a substance is the point where:

Accepted Answer

The liquid and gas phases become indistinguishable

Answer

The substance reaches its maximum density

Answer

The solid and liquid phases become indistinguishable

Answer

The gas and solid phases become indistinguishable