Second Law of Thermodynamics topics include: Second law of thermodynamics, cyclic heat engine, kelvin planck statement, refrigerator and heat pump, carnot theorem, absolute temperature scales and clausius theorem. The second law of thermodynamics is a physical law that describes the direction of spontaneous processes and the interconversion of heat and energy.  It states that: Heat always flows from hotter to colder regions of matter. Entropy, the degree of randomness or disorder in a system, tends to increase over time. Every energy transfer increases entropy and reduces the amount of... Show more

Second Law of Thermodynamics topics include: Second law of thermodynamics, cyclic heat engine, kelvin planck statement, refrigerator and heat pump, carnot theorem, absolute temperature scales and clausius theorem.

The second law of thermodynamics is a physical law that describes the direction of spontaneous processes and the interconversion of heat and energy. 

It states that:
Heat always flows from hotter to colder regions of matter.
Entropy, the degree of randomness or disorder in a system, tends to increase over time.
Every energy transfer increases entropy and reduces the amount of usable energy available to do work.
It is impossible for heat transfer from a reservoir to completely convert to work in a cyclical process. 

The second law of thermodynamics is also known as the Law of Increased Entropy. It limits the direction of heat transfer and the achievable efficiencies of heat engines. For example, it is impossible to convert heat energy to mechanical energy with 100% efficiency. 

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Thermodynamics Practice Test: Second Law of Thermodynamics

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25 Questions

1. A reversible cycle has following processes.

4 isothermal processesnone of these2 isothermal and 2 adiabatic processes4 adiabatic processes

2. Two reversible adiabatic paths can intersect each other.

TrueDon't KnowMaybeFalse

3. At absolute zero, an isotherm and an adiabatic are identical.

TrueDon't KnowMaybeFalse

4. It is necessary to have a temperature difference to obtain work of any cycle.

Don't KnowMaybeFalseTrue

5. In a heat engine cycle, which of the following process occurs?

all of the mentionedwork is produced in turbine rotorsteam is condensed in condenserheat is transferred from furnace to boiler

6. Free expansion is irreversible.

FalseMaybeDon't KnowTrue

7. What does a refrigerant do?

evaporates in the evaporatorabsorbs the heat leakage into body from surroundingsall of the mentionedabsorbs latent heat of vaporization form the body which is cooled

8. Irreversibility can be distinguished in how many types?

0312

9. The external irreversibility occurs at the system boundary.

Don't KnowMaybeTrueFalse

10. If the cyclic integral of dQ/T is less than zero then the cycle is

impossibleirreversible and possibleirreversible but not possiblereversible

11. Carnot cycle is a reversible cycle.

Don't KnowTrueMaybeFalse

12. Which of the following is true?

complete conversion of low grade energy into high grade energy in a cycle is impossibleall of the mentionedwork is a high grade energyheat is a low grade energy

13. The efficiency of a general cycle will be _____ the efficiency of a reversible cycle.

equal to or less thanequal to or greater thanless thanequal to

14. According to Kelvin-Planck statement, it is ____ for a heat engine to produce net work in a complete cycle if it exchanges heat only with bodies at ____

impossible, changing temperaturepossible, single fixed temperaturepossible, changing temperatureimpossible, single fixed temperature

15. Which of the following can be a cause of irreversibility?

all of the mentionedfriction, viscosityinelasticityelectrical resistance, magnetic hysteresis

16. The food compartment of a refrigerator is maintained at 4°C by removing heat from it at a rate of 360 kJ/min. If the required power input to the refrigerator is 2kW, determine the rate of heat rejection to the room that houses the refrigerator.

470 kJ/min460 kJ/min480 kJ/min450 kJ/min

17. In defining the temperature scale, the standard reference point is taken as

zero kelvinnone of theseboiling point of watertriple point of water

18. Which of the following statements are true?

a heat pump provides a thermodynamic advantage over direct heatingCOP for both refrigerator and pump cannot be infinitywork input for both refrigerator and pump is greater than zeroall of the mentioned

19. The continual motion of a movable device in the complete absence of friction is known as

PMM0PMM1PMM2PMM3

20. A cyclic machine, as shown below, receives 325 kJ from a 1000 K energy reservoir. It rejects 125 kJ to a 400 K energy reservoir and the cycle produces 200kJ of work as output. Is this cycle reversible, irreversible, or impossible?

none of thesereversibleirreversibleimpossible

21. A reversible process coincides with a quasi-static process.

TrueFalseDon't KnowMaybe

22. If heat rejected from the system Q2 is zero, then

all of the mentionedheat is exchanged only with one reservoirnet work=Q1 and efficiency=1.00it violates the Kelvin-Planck statement

23. Which if the following statements are true for a mechanical energy reservoir(MER)?

all of the mentionedit is a large body enclosed by an adiabatic impermeable wallall processes within an MER are quasi-staticstores work as KE or PE

24. The second law is not a deduction of the first law.

TrueFalseDon't KnowMaybe

25. According to the Clausius’ theorem, the cyclic integral of ____ for a reversible cycle is zero.

dE/dTdW/dTdQ/dTdH/dT