Engineering Thermodynamics Quizzes: Master the Fundamentals

Question 1

In an isentropic process, what is the change in entropy?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Unpredictable

Question 2

Which mathematical expression represents the first law of thermodynamics?

Accepted Answer

dQ = dU + dW

Answer

dS = dQ/T

Answer

PV = nRT

Answer

E = mc^2

Question 3

How are the specific heat at constant volume (Cv) and specific heat at constant pressure (Cp) related?

Accepted Answer

Cv = Cp + R

Answer

Cv > Cp

Answer

Cv = Cp

Answer

Cv < Cp

Question 4

Which thermodynamic process involves constant temperature?

Accepted Answer

Isothermal

Answer

Adiabatic

Answer

Isobaric

Answer

Isochoric

Question 5

For a closed system undergoing a reversible process, how is the change in internal energy (dU) expressed?

Accepted Answer

TdS - PdV

Answer

TdS + PdV

Answer

dQ - dW

Answer

dQ + dW

Question 6

What does entropy measure?

Accepted Answer

The disorder or randomness of a system.

Answer

The energy of a system.

Answer

The temperature of a system.

Answer

The volume of a system.

Question 7

In engineering thermodynamics, what is the primary significance of exergy?

Accepted Answer

It represents the maximum useful work obtainable from a system.

Answer

It measures the system's total energy content.

Answer

It determines the efficiency of a thermodynamic process.

Answer

It's only significant in closed thermodynamic systems.

Question 8

How does entropy generation impact the maximum achievable efficiency of a heat engine?

Accepted Answer

Reduces efficiency

Answer

No effect on efficiency

Answer

Increases efficiency

Question 9

Which Maxwell relation expresses the partial derivative of volume (V) with respect to temperature (T) at constant pressure (P)?

Accepted Answer

(∂S/∂P)T

Answer

(-∂P/∂T)v

Answer

-(∂U/∂P)T

Question 10

In an isobaric process, which of the following remains constant?

Accepted Answer

Pressure

Answer

Temperature

Answer

Volume

Answer

Entropy

Question 11

Which of the following is the SI unit of specific heat capacity?

Accepted Answer

Joule per kilogram Kelvin

Answer

Kelvin

Answer

Pascal

Answer

Watt

Question 12

Which of the following laws of thermodynamics states that the total entropy of an isolated system cannot decrease?

Accepted Answer

Second Law

Answer

Zeroth Law

Answer

First Law

Answer

Third Law

Question 13

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

Accepted Answer

A sealed container filled with air

Answer

A steam turbine

Answer

A heat sink

Answer

A Carnot cycle

Question 14

Which of the following devices transfers heat from one fluid to another?

Accepted Answer

Heat exchanger

Answer

Compressor

Answer

Turbine

Answer

Condenser

Question 15

Which of the following dimensionless numbers is used to characterize buoyancy-driven fluid flow?

Accepted Answer

Grashof number

Answer

Prandtl number

Answer

Nusselt number

Answer

Mach number

Question 16

Which of the following assumptions is commonly used to simplify thermodynamic analysis of systems with negligible friction?

Accepted Answer

Negligible pressure drop

Answer

Isothermal conditions

Answer

Adiabatic conditions

Answer

No heat transfer

Question 17

Which of the following quantities measures the degree of chaos or disorder within a system?

Accepted Answer

Entropy

Answer

Temperature

Answer

Work

Answer

Energy

Question 18

An isothermal process is characterized by:

Accepted Answer

Constant temperature.

Answer

Constant pressure.

Answer

Constant volume.

Question 19

When heat is added to a system at constant temperature, what happens to its entropy?

Accepted Answer

It increases.

Answer

It decreases.

Answer

It remains unchanged.

Question 20

The specific heat capacity of a substance refers to:

Accepted Answer

The amount of heat required to raise the temperature of 1 unit mass by 1 unit temperature.

Answer

The amount of heat required to raise the temperature of 1 unit volume by 1 unit temperature.

Answer

The amount of heat required to raise the temperature of 1 unit mass by 1 unit energy.

Question 21

Which of the following heat transfer mechanisms occurs without the movement of matter?

Accepted Answer

Radiation

Answer

Convection

Answer

Conduction

Question 22

The Carnot cycle describes:

Accepted Answer

A theoretical heat engine with maximum efficiency.

Answer

A type of refrigeration cycle.

Answer

A device used to measure temperature.

Question 23

**Which of the following statements accurately describes the first law of thermodynamics?**

Accepted Answer

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

Answer

Entropy decreases in isolated systems.

Answer

Heat always flows from hot objects to cold objects.

Question 24

**Which thermodynamic process involves a constant temperature?**

Accepted Answer

Isothermal

Answer

Isochoric

Answer

Adiabatic

Answer

Isobaric

Question 25

**The ideal gas constant, often denoted as R, is numerically equal to:**

Accepted Answer

8.314 J/(mol·K)

Answer

6.022 J/(mol·K)

Answer

9.81 J/(mol·K)

Answer

10.0 J/(mol·K)

Question 26

**Which of the following terms refers to thermal energy in transit?**

Accepted Answer

Heat

Answer

Entropy

Answer

Exergy

Answer

Enthalpy

Question 27

**How is absolute temperature related to the Kelvin temperature scale?**

Accepted Answer

Absolute temperature is the Kelvin temperature plus 273.15.

Answer

Absolute temperature is the Kelvin temperature minus 273.15.

Answer

Absolute temperature is twice the Kelvin temperature.

Question 28

In a closed system undergoing an isentropic process, which of the following remains constant?

Accepted Answer

Entropy

Answer

Internal energy

Answer

Pressure

Answer

Volume

Question 29

Which of the following is NOT a thermodynamic property?

Accepted Answer

Mass

Answer

Specific heat capacity

Answer

Temperature

Answer

Pressure

Question 30

Which of the following processes is isentropic?

Accepted Answer

A frictionless and reversible process

Answer

An irreversible process with no heat transfer

Answer

An irreversible process with heat transfer

Answer

A reversible process with heat transfer

Question 31

The first law of thermodynamics expresses the conservation of which quantity?

Accepted Answer

Energy

Answer

Mass

Answer

Charge

Answer

Momentum

Question 32

Which of the following is a closed thermodynamic system?

Accepted Answer

A sealed container of gas

Answer

A flowing river

Answer

A burning candle

Answer

An open window

Question 33

The enthalpy change for a reaction can be calculated using the:

Accepted Answer

Enthalpy of formation

Answer

Gibbs free energy

Answer

Helmholtz free energy

Answer

Entropy of formation

Question 34

Which of the following is a characteristic of a reversible process?

Accepted Answer

Can be reversed without any net change in the system or surroundings

Answer

Involves heat transfer

Answer

Occurs spontaneously

Question 35

The maximum work that can be obtained from a closed system undergoing a reversible isothermal process is equal to the:

Accepted Answer

Change in Helmholtz free energy

Answer

Change in enthalpy

Answer

Change in internal energy

Answer

Change in entropy

Question 36

The thermodynamic property that measures the tendency of a system to undergo spontaneous change is:

Accepted Answer

Gibbs free energy

Answer

Volume

Answer

Enthalpy

Answer

Entropy

Question 37

Which of the following is NOT a property of a closed thermodynamic system?

Accepted Answer

Area

Answer

Volume

Answer

Temperature

Answer

Pressure

Question 38

According to the first law of thermodynamics, which of the following quantities can neither be created nor destroyed?

Accepted Answer

Energy

Answer

Momentum

Answer

Matter

Answer

Entropy

Question 39

An isothermal process is one in which:

Accepted Answer

Temperature remains constant.

Answer

Energy remains constant.

Answer

Volume remains constant.

Answer

Pressure remains constant.

Question 40

Thermal conductivity is a material property that:

Accepted Answer

Describes its ability to conduct heat.

Answer

Describes its ability to reflect heat.

Answer

Describes its ability to store heat.

Answer

Describes its ability to absorb heat.

Question 41

Which of the following is a characteristic of renewable energy sources?

Accepted Answer

They originate from naturally replenished sources.

Answer

They release pollutants.

Answer

They require significant ongoing maintenance.

Answer

They are limited in quantity.

Question 42

The primary driver of the greenhouse effect is:

Accepted Answer

Trapping of heat in the Earth's atmosphere.

Answer

Reflection of heat from the Earth's surface.

Answer

Absorption of heat by the Earth's oceans.

Question 43

A major benefit of combined heat and power (CHP) systems is:

Accepted Answer

Increased overall energy efficiency and reduced emissions.

Answer

Lower capital costs.

Answer

Reduced maintenance costs.

Answer

Increased reliability.