Energy Conservation and the First Law of Thermodynamics: Interactive Learning Quizzes

Question 1

Identify the defining characteristic of an adiabatic process.

Accepted Answer

No heat transfer

Answer

No work done

Answer

Constant entropy

Answer

Constant temperature

Question 2

Identify the fundamental assumption underlying the first law of thermodynamics.

Accepted Answer

Energy conservation

Answer

Entropy always increases

Answer

Temperature measures heat

Answer

Pressure measures volume

Question 3

A system undergoes a series of processes, returning to its initial state. What is true about the total work done by the system?

Accepted Answer

Zero

Answer

Positive

Answer

Negative

Answer

Depends on the path taken

Question 4

What is the definition of specific heat capacity?

Accepted Answer

Heat required to raise the temperature of one kilogram of the substance by one degree Celsius

Answer

Heat required to raise the temperature of one pound of the substance by one degree Fahrenheit

Answer

Ratio between temperature change and heat added

Answer

Equivalent to the thermal conductivity of the substance

Question 5

Characterize a reversible process.

Accepted Answer

Can be reversed without altering the system's entropy

Answer

Can be reversed without altering the system's energy

Answer

Can be reversed without altering the system's temperature

Answer

Can be reversed without altering the system's volume

Question 6

Which action will NOT augment a system's entropy?

Accepted Answer

Performing work on the system

Answer

Heating the system

Answer

Mixing two distinct substances

Answer

Expanding the system

Question 7

According to the First Law of Thermodynamics, energy can be:

Accepted Answer

Transferred or converted from one form to another

Answer

Created or destroyed

Answer

Both created and destroyed

Answer

Neither created nor destroyed

Question 8

In a closed system, the change in internal energy is equal to:

Accepted Answer

Heat added to the system minus work done by the system

Answer

Heat added to the system

Answer

Work done by the system

Answer

Work done by the system minus heat added to the system

Question 9

In a steady-flow process, the quantity that remains constant is:

Accepted Answer

Mass flow rate

Answer

Temperature

Answer

Pressure

Answer

Velocity

Question 10

The efficiency of a Carnot heat engine operating between temperatures T1 and T2 is:

Accepted Answer

1 - (T2 / T1)

Answer

(T1 - T2) / T1

Answer

(T2 - T1) / T2

Answer

1 - (T1 / T2)

Question 11

What is the result of mass conservation?

Accepted Answer

The total mass of an isolated system remains constant.

Answer

The volume of an open system cannot change.

Answer

The pressure of a closed system cannot decrease.

Answer

The temperature of a system cannot increase.

Question 12

A piston-cylinder system holds air at constant pressure. Heat is added to the system, causing the piston to move and the air's volume to expand. How much work does the system do?

Accepted Answer

The pressure multiplied by the change in volume.

Answer

The change in internal energy.

Answer

Zero.

Answer

The same as the heat added.

Question 13

The efficiency of a heat engine is defined as:

Accepted Answer

Work output over Heat input.

Answer

Heat input over Work output.

Answer

Heat rejected over Heat input.

Answer

Change in internal energy over Heat input.

Question 14

In a closed thermodynamic system undergoing a process where external work is done on the system, heat transfer must occur in which direction to satisfy the first law of thermodynamics?

Accepted Answer

Heat must be added to the system.

Answer

Heat must be removed from the system.

Answer

Heat transfer does not occur.

Answer

The direction of heat transfer cannot be determined without additional information.

Question 15

In an adiabatic process occurring within a closed system, what occurs to the heat transfer and internal energy?

Accepted Answer

No heat transfer occurs, and internal energy remains unchanged.

Answer

Heat flows into the system, causing an increase in internal energy.

Answer

Heat flows out of the system, leading to a decrease in internal energy.

Answer

Heat flows into the system, but internal energy remains constant.

Question 16

According to the principle of energy conservation, energy:

Accepted Answer

Can neither be created nor destroyed.

Answer

Can be created but not destroyed.

Answer

Can be destroyed but not created.

Answer

Can be both created and destroyed.

Question 17

In a closed thermodynamic system, the only forms of energy that can cross the system boundary are:

Accepted Answer

Heat and work

Answer

Heat and internal energy

Answer

Work and momentum

Answer

Momentum and internal energy

Question 18

Which of the following is NOT a key concept in the First Law of Thermodynamics?

Accepted Answer

Entropy

Answer

Internal energy

Answer

Heat

Answer

Work

Question 19

In an isothermal process, the internal energy of the system:

Accepted Answer

Remains constant

Answer

Increases

Answer

Decreases

Answer

Cannot be determined

Question 20

Which of the following is a valid thermodynamic property?

Accepted Answer

Temperature

Answer

Velocity

Answer

Acceleration

Answer

Mass

Question 21

In a throttling process:

Accepted Answer

Enthalpy remains constant

Answer

Enthalpy increases

Answer

Enthalpy decreases

Answer

Cannot be determined

Question 22

The efficiency of a heat engine is defined as:

Accepted Answer

The ratio of the work output to the heat input

Answer

The ratio of the heat input to the work output

Answer

The ratio of the change in internal energy to the heat input

Answer

The ratio of the change in internal energy to the work output

Question 23

Which thermodynamic process is characterized by the absence of heat transfer?

Accepted Answer

Adiabatic

Answer

Isothermal

Answer

Isobaric

Answer

Isentropic

Question 24

In an isobaric process where pressure remains constant, the heat transferred into a system (δQ) is related to the change in internal energy (dU) and work done by the system (δW) as:

Accepted Answer

δQ = dU + δW

Answer

δQ = dU

Answer

δW = dU + δQ

Answer

dU = δQ - δW

Question 25

The SI unit of specific heat capacity, which measures the amount of heat required to raise the temperature of a unit mass by one degree, is:

Accepted Answer

Joules per kilogram Kelvin (J/kg K)

Answer

Joules per kilogram (J/kg)

Answer

Joules per Kelvin (J/K)

Answer

Kilojoules per kilogram (kJ/kg)

Question 26

The second law of thermodynamics implies that:

Accepted Answer

The total entropy of an isolated system can only increase or remain constant.

Answer

Energy can neither be created nor destroyed, only transformed.

Answer

Heat always flows from cold bodies to hot bodies.

Answer

The efficiency of a heat engine is directly proportional to its operating temperature.

Question 27

Which of the following statements best explains the concept of irreversibility in thermodynamics?

Accepted Answer

Irreversible processes lead to an increase in the entropy of the universe.

Answer

Irreversible processes cannot be restored to their initial state due to energy loss.

Answer

Irreversible processes always involve heat transfer.

Answer

Irreversible processes violate the laws of thermodynamics.

Question 28

State the fundamental principle of energy conservation, as described by the First Law of Thermodynamics.

Accepted Answer

Energy can neither be created nor destroyed, but can only be transferred or transformed from one form to another.

Answer

Work and heat are the sole forms of energy.

Answer

The sum of energy within an isolated system is constant.

Question 29

Identify the option that does NOT represent a valid form of energy transfer:

Accepted Answer

Mass transfer

Answer

Heat transfer

Answer

Work transfer

Answer

Radiation transfer

Question 30

Define an adiabatic process.

Accepted Answer

A process where no heat is exchanged with the surroundings.

Answer

A process where the system's temperature remains constant.

Answer

A process where the system is in thermal equilibrium with its surroundings.

Question 31

In an open system, if the work done by the system exceeds the heat added to the system, what will happen to the system's internal energy?

Accepted Answer

It will decrease.

Answer

It will increase.

Answer

It will remain constant.

Answer

It will become negative.

Question 32

Which of the following is considered a primary source of renewable energy?

Accepted Answer

Solar energy

Answer

Fossil fuels

Answer

Natural gas

Answer

Nuclear energy

Question 33

The First Law of Thermodynamics states that:

Accepted Answer

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

Answer

The entropy of an isolated system always increases.

Answer

Heat always flows from hot to cold.

Question 34

An adiabatic process involves:

Accepted Answer

No heat transfer into or out of the system.

Answer

Constant temperature.

Answer

Constant pressure.

Answer

No work done by or on the system.

Question 35

The efficiency of a heat engine is defined as:

Accepted Answer

The ratio of the net work output to the heat input.

Answer

The product of the heat input and the net work output.

Answer

The difference between the heat input and the net work output.

Answer

The ratio of the heat input to the net work output.

Question 36

The Carnot cycle represents a heat engine operating with:

Accepted Answer

The maximum possible efficiency for a given temperature difference.

Answer

An efficiency that is always less than 100%.

Answer

The minimum possible efficiency for a given temperature difference.

Answer

An efficiency that is always equal to 100%.

Question 37

Which of the following factors influences the efficiency of a heat engine?

Accepted Answer

Temperature difference between the heat source and sink.

Answer

Volume of the engine.

Answer

Type of fuel used.

Question 38

Energy conservation implies that:

Accepted Answer

The total amount of energy in an isolated system remains constant.

Answer

Energy can be created or destroyed under certain conditions.

Answer

The efficiency of energy conversion is always 100%.

Question 39

The First Law of Thermodynamics is concerned with:

Accepted Answer

The conservation of energy.

Answer

The properties of ideal gases.

Answer

The direction of heat flow.

Answer

The efficiency of heat engines.