Closed and Open Systems Analysis: Thermodynamics for Engineers

Question 1

In a closed system, what is the characteristic regarding mass and energy transfer?

Accepted Answer

Neither mass nor energy is exchanged.

Answer

Mass is exchanged, but energy is conserved.

Answer

Energy is exchanged, but mass is conserved.

Answer

Both mass and energy are exchanged.

Question 2

In an open system, what is conserved?

Accepted Answer

Mass

Answer

Energy

Answer

Momentum

Answer

Volume

Question 3

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

Accepted Answer

First Law

Answer

Second Law

Answer

Third Law

Answer

Zeroth Law

Question 4

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

Accepted Answer

Adsorption

Answer

Conduction

Answer

Convection

Answer

Radiation

Question 5

Which thermodynamic property represents the system's potential to do work?

Accepted Answer

Exergy

Answer

Internal energy

Answer

Enthalpy

Answer

Entropy

Question 6

Which of the following is NOT a thermodynamic property?

Accepted Answer

Power

Answer

Temperature

Answer

Pressure

Answer

Volume

Question 7

Which characteristic describes a closed system?

Accepted Answer

Fixed mass and volume

Answer

Variable mass and volume

Answer

Fixed mass and variable volume

Answer

Variable mass and fixed volume

Question 8

For an isothermal process in a closed system, what holds true?

Accepted Answer

No heat transfer occurs and the system volume remains constant.

Answer

Heat enters the system and the system does work.

Answer

Heat exits the system and the system is compressed.

Answer

No heat transfer occurs and the system expands.

Question 9

Which of the following is NOT a mode of energy transfer into or out of an open system?

Accepted Answer

Momentum

Answer

Heat

Answer

Work

Answer

Mass flow

Question 10

Which mathematical expression represents the First Law of Thermodynamics for an open system?

Accepted Answer

dQ = dU + dW

Answer

dQ = dU - dW

Answer

dU = dQ + dW

Answer

dU = dQ - dW

Question 11

Consider a piston-cylinder system containing an ideal gas. If the gas expands and performs work on its surroundings, what happens to the system's internal energy?

Accepted Answer

It decreases.

Answer

It increases.

Answer

It remains constant.

Answer

It becomes zero.

Question 12

In a heat exchanger, the heat transfer rate between two fluids is calculated using which formula?

Accepted Answer

Q = UAΔT

Answer

Q = UAdT

Answer

Q = mCp(T2 - T1)

Answer

Q = mCp(T1 - T2)

Question 13

In a closed adiabatic process, which property remains unchanged?

Accepted Answer

Entropy

Answer

Pressure

Answer

Temperature

Answer

Volume

Question 14

A defining characteristic of open systems is:

Accepted Answer

Mass exchange across boundaries

Answer

Absence of energy transfer

Answer

Constant temperature

Answer

Equilibrium state

Question 15

Which of the following is not a mode of energy transfer?

Accepted Answer

Mass

Answer

Heat

Answer

Work

Answer

Radiation

Question 16

During an isothermal process of an ideal gas, which variable remains constant?

Accepted Answer

Temperature

Answer

Volume

Answer

Pressure

Answer

Entropy

Question 17

In an adiabatic turbine, the working fluid:

Accepted Answer

Experiences no heat transfer

Answer

Absorbs heat from surroundings

Answer

Releases heat to surroundings

Answer

Undergoes reversible expansion

Question 18

A fundamental assumption of the First Law of Thermodynamics is:

Accepted Answer

Energy conservation

Answer

Constant entropy

Answer

Closed systems

Answer

Reversible processes

Question 19

The primary function of a heat exchanger is to:

Accepted Answer

Transfer heat between fluids

Answer

Convert heat to work

Answer

Store thermal energy

Answer

Measure temperature differences

Question 20

Which of the following systems is an example of an open system?

Accepted Answer

A steam turbine

Answer

A sealed container of gas

Answer

A refrigerator

Answer

A car battery

Question 21

In a closed system, which of the following is conserved?

Accepted Answer

Both mass and energy

Answer

Mass

Answer

Energy

Answer

Neither mass nor energy

Question 22

Which of the following is NOT a characteristic of an open system?

Accepted Answer

The system is isolated from its surroundings

Answer

Mass can enter or leave the system

Answer

Energy can enter or leave the system

Answer

Properties can change with time

Question 23

The First Law of Thermodynamics can be applied to:

Accepted Answer

Both closed and open systems

Answer

Closed systems only

Answer

Open systems only

Answer

Neither closed nor open systems

Question 24

Which of the following processes is isobaric?

Accepted Answer

Constant pressure process

Answer

Constant volume process

Answer

Constant temperature process

Answer

Adiabatic process

Question 25

The efficiency of a heat engine is defined as:

Accepted Answer

Work output / Heat input

Answer

Heat input / Work output

Answer

Heat output / Work input

Answer

Work output / Heat output

Question 26

In thermodynamics, internal energy refers to:

Accepted Answer

All forms of energy possessed by the constituents of a system

Answer

Energy present in the surroundings of a system

Answer

Energy solely determined by the temperature of a system

Question 27

In a closed system, which property does NOT remain constant?

Accepted Answer

Momentum

Answer

Mass

Answer

Energy

Answer

Entropy

Question 28

Which of the following is NOT a key characteristic of an open system?

Accepted Answer

Volume remains constant

Answer

Mass can enter or leave the system

Answer

Energy can enter or leave the system

Answer

Entropy can enter or leave the system

Question 29

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

Accepted Answer

Entropy

Answer

Temperature

Answer

Pressure

Answer

Volume

Question 30

The enthalpy of a system is defined as:

Accepted Answer

Internal energy + pressure volume

Answer

Internal energy + temperature volume

Answer

Internal energy - pressure volume

Answer

Internal energy - temperature volume

Question 31

In a steady-flow process, which of the following is NOT constant?

Accepted Answer

Volume

Answer

Mass flow rate

Answer

Energy flow rate

Answer

Entropy flow rate

Question 32

The entropy of a system is a measure of its:

Accepted Answer

Randomness

Answer

Orderliness

Answer

Energy

Answer

Temperature

Question 33

Which of the following is an example of an open system commonly found in engineering applications?

Accepted Answer

Heat exchanger

Answer

Turbine

Answer

Compressor

Answer

Accumulator

Question 34

In a closed system, which of the following is not necessarily conserved?

Accepted Answer

Volume

Answer

Mass

Answer

Entropy

Question 35

For an open system undergoing a steady-state process, the rate of energy entering the system is:

Accepted Answer

Equal to the rate of energy leaving the system

Answer

Greater than the rate of energy leaving the system

Answer

Less than the rate of energy leaving the system

Answer

Cannot be determined without additional information

Question 36

The specific heat capacity of a substance is:

Accepted Answer

The amount of heat required to raise the temperature of 1 kg of the substance by 1 K

Answer

The amount of heat required to raise the temperature of 1 g of the substance by 1 °C

Question 37

The Carnot cycle is a hypothetical heat engine that operates between:

Accepted Answer

Two isothermal and two adiabatic processes

Answer

Two isobaric and two isochoric processes

Question 38

The efficiency of a heat engine is limited by:

Accepted Answer

The Carnot efficiency

Answer

The heat of combustion

Question 39

The change in entropy during a reversible process is:

Accepted Answer

Equal to the heat transferred divided by the temperature

Answer

Greater than the heat transfer divided by the temperature

Question 40

In an open system, the net rate of energy transfer:

Accepted Answer

Depends on the system's boundary conditions

Answer

Is always zero

Answer

Is equal to the rate of heat transfer

Answer

Is equal to the rate of work transfer

Question 41

Which of the following processes involves no heat transfer?

Accepted Answer

Adiabatic

Answer

Isothermal

Answer

Isochoric

Answer

Isobaric

Question 42

The relationship between entropy and the number of possible microstates of a system is:

Accepted Answer

Entropy is proportional to the natural logarithm of the number of microstates

Answer

Entropy is inversely proportional to the number of microstates

Answer

There is no relationship between entropy and the number of microstates

Answer

Entropy is proportional to the square root of the number of microstates

Question 43

The significance of the ideal gas law lies in:

Accepted Answer

Being a fundamental equation of state

Answer

Describing gas behaviour at high pressures and low temperatures

Answer

Applying to all gases under all conditions

Answer

Calculating the adiabatic index of a gas

Question 44

Which of the following does NOT affect the efficiency of a heat engine?

Accepted Answer

Volume of the engine

Answer

Temperature of the heat source and sink

Answer

Type of working fluid

Answer

Design of the engine

Question 45

A fundamental assumption of the First Law of Thermodynamics is that:

Accepted Answer

Energy cannot be created or destroyed

Answer

All processes are reversible

Answer

The system is in equilibrium

Answer

The temperature is constant

Question 46

A key concept related to entropy is:

Accepted Answer

Disorder

Answer

Reversibility

Answer

Energy conservation

Answer

Heat transfer

Question 47

In a closed system, which of the following remains constant?

Accepted Answer

Mass and energy

Answer

Mass and volume

Answer

Volume and energy

Answer

Mass only

Question 48

Identify the boundary condition for mass transfer in a closed system:

Accepted Answer

No mass can exchange the system

Answer

Mass can only enter the system

Answer

Mass can only leave the system

Answer

Mass can be exchanged freely

Question 49

For a closed system undergoing a reversible constant-volume process, what is the change in internal energy?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Cannot be determined

Question 50

Which of the following is NOT a mode of energy transfer in an open system?

Accepted Answer

Conduction

Answer

Work

Answer

Heat

Answer

Mass flow

Question 51

What quantities are balanced in the steady-state energy equation for an open system?

Accepted Answer

Inflow and outflow energy rates

Answer

Inflow and outflow rates

Answer

Inflow and outflow mass rates

Answer

Inflow, outflow, and generation rates

Question 52

Which of the following characterizes an adiabatic process?

Accepted Answer

No heat transfer

Answer

No work transfer

Answer

No mass transfer

Answer

No change in internal energy

Question 53

Which of these is a key assumption in the analysis of ideal gases?

Accepted Answer

Negligible intermolecular forces

Answer

Constant specific heats

Answer

Adiabatic processes

Answer

No energy transfer

Question 54

For a closed system undergoing a reversible process, the entropy change is:

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Indeterminate

Question 55

In an open system, the mass flow rate is typically expressed in:

Accepted Answer

kg/s

Answer

kg/m^3

Answer

J/s

Answer

W

Question 56

Which fundamental law governs energy transfer and conversion in closed and open thermodynamic systems?

Accepted Answer

First Law of Thermodynamics

Answer

Newton's Second Law

Answer

Zeroth Law of Thermodynamics

Answer

Entropy Law

Question 57

In a closed system, the mass remains constant. Is this statement true or false?

Accepted Answer

True

Answer

False

Question 58

The change in internal energy of a system can be calculated as:

Accepted Answer

Heat added - Work done

Answer

Heat added + Work done

Answer

Work done - Heat added

Answer

Heat added - Heat rejected

Question 59

The mass flow rate through an open system is defined as:

Accepted Answer

The amount of mass entering minus the amount of mass leaving the system per unit time

Answer

The rate of change of mass within the system

Answer

The total mass of the system divided by the time

Answer

The mass of the system multiplied by the velocity at which it is moving

Question 60

Which assumption is crucial for applying the First Law of Thermodynamics to open systems?

Accepted Answer

Steady-state conditions

Answer

No heat transfer

Answer

No work done

Answer

No fluid flow

Question 61

The power output of an open system is given by:

Accepted Answer

The rate of work done minus the rate of heat transfer

Answer

The change in energy of the system per unit time

Answer

The rate of heat transfer minus the rate of work done

Answer

The total energy of the system divided by the time

Question 62

Which factor does NOT influence the efficiency of a closed system heat engine?

Accepted Answer

Number of stages in the engine

Answer

Temperature difference between the source and sink

Answer

Type of working fluid

Answer

Pressure ratio

Question 63

The Carnot efficiency of a heat engine represents the highest possible efficiency achievable. Is this statement true or false?

Accepted Answer

True

Answer

False