Homework answers / question archive / University of Alabama, Birmingham - ELC 101 THERMODYNAMICS - GEAS SERIES 1)What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state? •          A

University of Alabama, Birmingham - ELC 101 THERMODYNAMICS - GEAS SERIES 1)What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state? •          A

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University of Alabama, Birmingham - ELC 101

THERMODYNAMICS - GEAS SERIES

1)What is defined as the direct conversion of a substance from the solid to the vapor state or vice versa without passing the liquid state?

•          A. Condensation

•          B. Vaporization

•          C. Sublimation

•          D. Cryogenation

2.         The amount of heat required to raise the temperature of 1kg of water through 1 °C is called       .

•          A. Calorie

•          B. Joule

•          C. BTU

•          D. Kilocalorie

3.         The amount of heat required to raise the temperature of 1 pound of water by 1°F is called          .

•          A. Calorie

•          B. Joule

•          C. BTU

•          D. Kilocalorie

4.         1 British thermal unit (BTU) is equivalent to how many joules?

•          A. 1016

•          B. 1043

•          C. 1023

•          D. 1054

5.         The term “enthalpy” comes from Greek “enthalpen” which means .

•          A. Warm

•          B. Hot

•          C. Heat

•          D. Cold

6.         The ratio of the mass of vapor to the total mass of the mixture is called    .

•          A. Vapor ratio

•          B. Vapor content

•          C. Vapor index

•          D. Quality

7.         The “equation of state” refers to any equation that relates the       of the substance.

•          A. Pressure and temperature

•          B. Pressure, temperature and specific weight

•          C. Temperature and specific weight

•          D. Pressure, temperature and specific volume

8.         In the equation Pv = RT, the constant of proportionality R is known as        .

•          A. Universal gas constant

•          B. Gas constant

•          C. Ideal gas factor

•          D. Gas index

9.         The gas constant of a certain gas is the ratio of:

•          A. Universal gas constant to molar mass

10. What is the value of the universal gas constant in kJ/kmol ?

K?

•          A. 10.73

•          B. 1.986

•          C. 8.314

•          D. 1545

11.       The mass of one mole of a substance in grams is known as

            .

a.         A. Molar weight

b.         B. Molar mass

c.         C. Molar volume

d.         D. Molar constant

12.       What is defined as the energy required to raise the temperature of a unit mass of a substance by one degree?

a.         A. Latent heat of fusion

b.         B. Molar heat

c.         C. Specific heat capacity

d.         D. Specific heat

13.       The      of a substance is the amount of heat that must be added or removed from a unit mass of the substance to change its temperature by one degree.

a.         A. Latent heat of fusion

b.         B. Molar heat

c.         C. Specific heat capacity

d.         D. Specific heat

14.       What is the specific heat capacity of water in J/kg ?°C?

a.         A. 4581

b.         B. 4185

c.         C. 4518

d.         D. 4815

15.       What is the SI unit of specific heat capacity?

a.         A. J/kg

b.         B. J/kg? °F

c.         C. J/kg? °C

d.         D. J/°C

16.       What is constant for a substance that is considered “incompressible”?

a.         A. Specific volume of density

b.         B. Pressure

c.         C. Temperature

d.         D. All of the above

17.       If there is no heat transferred during the process, it is called a       process.

a.         A. Static

b.         B. Isobaric

c.         C. Polytropic

d.         D. Adiabatic

18.       The term “adiabatic” comes from Greek “adiabatos” which means            .

a.         A. No heat

b.         B. No transfer

c.         C. Not to be passed

d.         D. No transformation

 

e.         A. By conduction

f.          B. By convection

g.         C. By radiation

h.         D. All of the above

19.       What refers to the transfer of energy due to the emission of electromagnetic waves or photons?

a.         A. Conduction

b.         B. Convection

c.         C. Radiation

d.         D. Electrification

20.       What refers to the transfer of energy between a solid surface and the adjacent fluid that is in motion?

a.         A. Conduction

b.         B. Convection

c.         C. Radiation

d.         D. Electrification

21.       What refers to the transfer of energy from the more energetic particles of a substance to the adjacent less energetic ones as a result of interaction between particles?

a.         A. Conduction

b.         B. Convection

c.         C. Radiation

d.         D. Electrification

22.       What states that the net mass transfer to or from a system during a process is equal to the net change in the total mass of the system during that process?

a.         A. Third law of thermodynamics

b.         B. Conservation of energy principle

c.         C. Second law of thermodynamic

d.         D. Conservation of mass principle

23.       Which of the following statements is TRUE for an ideal gas, but not for a real gas?

a.         A. PV = nRT

b.         B. An increase in temperature causes an increase in the kinetic energy of the gas

c.         C. The total volume of molecules on a gas is nearly the

same as the volume of the gas as a whole

d.         D. No attractive forces exists between the molecule of a

gas

24.       How does an adiabatic process compare to an isentropic process?

a.         A. Adiabatic heat transfer is not equal to zero; isentropic heat transfer is zero

b.         B. Both heat transfer = 0; isentropic: reversible

c.         C. Adiabatic heat transfer = 0; isentropic: heat transfer is not equal to zero

d.         D. Both heat transfer is not equal to zero; isentropic:

irreversible

25.       Which of the following is the Ideal gas law (equation)?

a.         A. V/T = K

b.         B. V= k*(1/P)

c.         C. P1/T1 = P2/T2

d.         D. PV = nRT

26.       What is a measure of the ability of a material to conduct heat?

a.         C. It is independent with the surface condition of the

 

b.         A. Specific heat capacity

c.         B. Coefficient of thermal expansion

d.         C. Coefficient of thermal conductivity

e.         D. Thermal conductivity

27.       What refers to the heating of the earth’s atmosphere not caused by direct sunlight but by infrared light radiated by the surface and absorbed mainly by atmospheric carbon dioxide?

a.         A. Greenhouse effect

b.         B. Global warming

c.         C. Thermal rise effect

d.         D. Ozone effect

28.       What is a form of mechanical work which is related with the expansion and compression of substances?

a.         A. Boundary work

b.         B. Thermodynamic work

c.         C. Phase work

d.         D. System work

29.       Thermal radiation is an electromagnetic radiation with wavelengths in     range.

a.         A. 1 to 100 µm

b.         B. 0.1 to 100 µm

c.         C. 0.1 to 10 µm

d.         D. 10 to 100 µm

30.       What refers to the rate of thermal radiation emitter per unit area of a body?

a.         A. Thermal conductivity

b.         B. Absorptivity

c.         C. Emissivity

d.         D. Emissive power

31.       What states that for any two bodies in thermal equilibrium, the ratios of emissive power to the absorptivity are equal?

a.         A. Kirchhoff’s radiation law

b.         B. Newton’s law of cooling

c.         C. Stefan-Boltzmann law

d.         D. Hess’s law

32.       What is considered as a perfect absorber as well as a perfect emitter?

a.         A. Gray body

b.         B. Black body

c.         C. Real body

d.         D. White body

33.       What is a body that emits a constant emissivity regardless of the wavelength?

a.         A. Gray body

b.         B. Black body

c.         C. Real body

d.         D. White body

34.       At same temperatures, the radiation emitted by all real surfaces is            the radiation emitted by a black body.

a.         A. Less than

b.         B. Greater than

c.         C. Equal to

d.         D. Either less than or greater than

35.       Which is NOT a characteristic of emissivity?

a.         A. It is high with most nonmetals

b.         B. It is directly proportional to temperature

 

material

c.         D. It is low with highly polished metals

36.       What is the emissivity of a black body?

a.         A. 0

b.         B. 1

c.         C. 0.5

d.         D. 0.25

37.       What is the absorptivity of a black body?

a.         A. 0

b.         B. 1

c.         C. 0.5

d.         D. 0.25

38.       What is sometimes known as the “Fourth-power law”?

a.         A. Kirchhoff’s radiation law

b.         B. Newton’s law of cooling

c.         C. Stefan-Boltzmann law

d.         D. Hess’s law

39.       What states that the net change in the total energy of the system during a process is equal to the difference between the total energy entering and the total energy leaving the system during that process?

a.         A. Third law of thermodynamics

b.         B. Conservation of energy principle

c.         C. Second law of thermodynamics

d.         D. Conservation of mass principle

40.       The equation Ein – Eout = ?Esystem is known as       .

a.         A. Energy conservation

b.         B. Energy equation

c.         C. Energy balance

d.         D. Energy conversion equation

41.       What remains constant during a steady-flow process?

a.         A. Mass

b.         B. Energy content of the control volume

c.         C. Temperature

d.         D. Mass and energy content of the control volume

42.       Thermal efficiency is the ratio of:

a.         A. Network input to total heat input

b.         B. Network output to total heat output

c.         C. Network output to total heat input

d.         D. Network input to total heat output

43.       What law states that it is impossible to operate an engine operating in a cycle that will have no other effect than to extract heat from a reservoir and turn it into an equivalent amount of work?

a.         A. Zeroth law of thermodynamics

b.         B. First law of thermodynamics

c.         C. Second law of thermodynamics

d.         D. Third law of thermodynamics

44.       Which statement of the second law of thermodynamics states that no heat engine can have a thermal efficiency of 100 percent?

a.         A. Kelvin-Planck statement

b.         B. Clausius statement

c.         C. Kevin statement

d.         D. Rankine statement

e.         C. 1832

 

45.       What is the ratio of the useful heat extracted to heating value?

a.         A. Combustion efficiency

b.         B. Phase efficiency

c.         C. Heat efficiency

d.         D. Work efficiency

46.       What is defined as the ratio of the net electrical power output to the rate of fuel energy input?

a.         A. Combustion efficiency

b.         B. Thermal efficiency

c.         C. Overall efficiency

d.         D. Furnace efficiency

47.       What refers to the amount of heat removed from the cooled space in BTS’s for 1 watt-hour of electricity consumed?

a.         A. Cost efficiency rating

b.         B. Energy efficiency rating

c.         C. Coefficient of performance

d.         D. Cost of performance

48.       What law states that it is impossible to build a device that operates in a cycle and produces no effect other than the transfer of heat from a lower-temperature body to a higher- temperature body?

a.         A. Zeroth law of thermodynamics

b.         B. First law of thermodynamics

c.         C. Second law of thermodynamics

d.         D. Third law of thermodynamics

49.       What statement of the second law of thermodynamics states that it is impossible to build a device that operates in a cycle and produces no effect other than the transfer of heat from a lower-temperature body to a higher-temperature body?

a.         A. Kelvin-Planck statement

b.         B. Clausius statement

c.         C. Kelvin statement

d.         D. Rankine statement

50.       A device that violates either the first law of thermodynamics or the second law of thermodynamics is known as         .

a.         A. Ambiguous machine

b.         B. Universal machine

c.         C. Perpetual-motion machine

d.         D. Unique machine

51.       A device that violates the first law of thermodynamics is called a   .

a.         A. Perpetual-motion machine of the first kind

b.         B. Universal machine of the first kind

c.         C. Ambiguous machine of the first kind

d.         D. Unique machine of the first kind

52.       A device that violates the second law of thermodynamics is called a          .

a.         A. Perpetual motion machine of the second kind

b.         B. Universal machine of the second kind

c.         C. Ambiguous machine of the second kind

d.         D. Unique machine of the second kind

53.       Carnot cycle is the best known reversible cycle which was first proposed in what year?

a.         A. 1842

b.         B. 1824

 

c.         D. 1834

54.       Who proposed the Carnot cycle?

a.         A. Sammy Carnot

b.         B. Sonny Carnot

c.         C. Sadi Carnot

d.         D. Suri Carnot

55.       The Carnot cycle is composed of how many reversible processes?

a.         A. 2

b.         B. 3

c.         C. 4

d.         D. 5

56.       The Carnot cycle is composed of        processes.

a.         A. One isothermal and one adiabatic

b.         B. One isothermal and two adiabatic

c.         C. Two isothermal and one adiabatic

d.         D. Two isothermal and two adiabatic

57.       What is the highest efficiency of heat engine operating between the two thermal energy reservoirs at temperature limits?

a.         A. Ericson efficiency

b.         B. Otto efficiency

c.         C. Carnot efficiency

d.         D. Stirling efficiency

58.       What is a heat engine that operates on the reversible Carnot cycle called?

a.         A. Carnot heat engine

b.         B. Ideal heat engine

c.         C. Most efficient heat engine

d.         D. Best heat engine

59.       What states that thermal efficiencies of all reversible heat engines operating between the same two reservoirs are the same and that no heat engine is more efficient than a reversible one operating between the same two reservoirs?

a.         A. Ericson principle

b.         B. Carnot principle

c.         C. Otto principle

d.         D. Stirling principle

60.       Who discovered the thermodynamic property “Entropy” in 1865?

a.         A. Zeroth law of thermodynamics

b.         B. First law of thermodynamics

c.         C. Second law of thermodynamics

d.         D. Third law of thermodynamics

61.       A process during which entropy remains constant is called

            process

a.         A. Isometric

b.         B. Isochoric

c.         C. Isobaric

d.         D. Isentropic

62.       “A reversible adiabatic process is necessarily isentropic but an isentropic process is not necessarily reversible adiabatic process.” This statement is:

a.         A. True

b.         B. False

c.         D. 0 degree Fahrenheit and zero pressure

63. What is the value of the work done for a closed, reversible

 

•          C. May be true and may be false

•          D. Absurd

 

 

 

 

64.       The term “isentropic process” used in thermodynamics implies what?

a.         A. Reversible adiabatic process

b.         B. Externally reversible, adiabatic process

c.         C. Internally reversible, adiabatic process

d.         D. Irreversible adiabatic process

65.       What states that the entropy of a pure crystalline substance at absolute zero temperature is zero?

a.         A. Zeroth law of thermodynamics

b.         B. First law of thermodynamics

c.         C. Second law of thermodynamics

d.         D. Third law of thermodynamics

66.       What law provides an absolute reference point for the determination of entropy?

a.         A. Zeroth law of thermodynamics

b.         B. First law of thermodynamics

c.         C. Second law of thermodynamics

d.         D. Third law of thermodynamics

67.       “The entropy change of a system during a process is equal to the net entropy transfer through the system boundary and the entropy generated within the system”. This statement is known as:

a.         A. Entropy generation

b.         B. Entropy change of a system

c.         C. Entropy balance relation

d.         D. Third law of thermodynamics

68.       What law states that entropy can be created but it cannot be destroyed?

a.         A. Zeroth law of thermodynamics

b.         B. First law of thermodynamics

c.         C. Second law of thermodynamics

d.         D. Third law of thermodynamics

69.       Entropy is transferred by        .

a.         A. Work

b.         B. Heat

c.         C. Energy

d.         D. Work and heat

70.       During adiabatic, internally reversible process, what is true about the change in entropy?

a.         A. It is temperature-dependent

b.         B. It is always greater than zero

c.         C. It is always zero

d.         D. It is always less than zero

71.       Water boils when:

a.         A. Its saturated vapor pressure equals to the atmospheric pressure

b.         B. Its vapor pressure equals 76cm of mercury

c.         C. Its temperature reaches 212 degree Celsius

d.         D. Its vapor pressure is 1 gram per sq. cm

72.       Which of the following is standard temperature and pressure (STP)?

a.         A. 0 degree Celsius and one atmosphere

b.         B. 32 degree Fahrenheit and zero pressure

c.         C. 0 degree Kelvin and one atmosphere

 

isometric system?

d.         A. Zero

e.         B. Positive

f.          C. Negative

g.         D. Positive or negative

73.       “At constant pressure, the volume of a gas is inversely proportional to the pressure”. This is known as            .

a.         A. Boyle’s Law

b.         B. Charles’s Law

c.         C. Gay-Lussac Law

d.         D. Ideal gas law

74.       Which of the following is the mathematical representation of the Charles’s law?

a.         A. V1/V2= P2/P1

b.         B. V1/T1=V2/T2

c.         C. V1/T2=V2/T1

d.         D. V1/V2=√P2/√P1

75.       Which of the following is the formula for thermal resistance?

a.         A. Thickness of material/ thermal conductivity of material

b.         B. 2(thickness of material)/thermal conductivity of

material

c.         C. Thickness of material/ 2(thermal conductivity of material)

d.         D. Thickness of material x thermal conductivity of

material

76.       In the process of radiation, energy is carried by electromagnetic waves. What is the speed of electromagnetic waves?

a.         A. 182,000 miles/second

b.         B. 184,000 miles/second

c.         C. 186,000 miles/second

d.         D. 188,000 miles/second

77.       For heat engine operating between two temperatures (T1>T2), what is the maximum efficiency attainable?

a.         A. Eff = 1 – (T2/T1)

b.         B. Eff = 1 - (T1/T2)

c.         C. Eff = T1 - T2

d.         D. Eff = 1 - (T2/T1)^2

78.       Which one is the correct relation between energy efficiency ratio (EER) and coefficient of performance (COP)?

a.         A. EER = 2.34 COP

b.         B. EER = 3.24 COP

c.         C. EER = 3.42 COP

d.         D. EER = 4.23 COP

79.       The coefficient of performance (COP) is the ratio between the:

a.         A. Power consumption in watts and heat absorbed per hour

b.         B. Heat absorbed per hour and the power consumption

in watts

c.         C. Work required and the absorbed heat

d.         D. Absorbed heat and work required

 

80.       What predicts the approximate molar specific heat at high temperatures from the atomic weight?

a.         A. Third law of thermodynamics

b.         B. Law of Dulong and Petit

c.         C. Mollier diagram

d.         D. Pressure-enthalpy diagram

81.       Considering one mole of any gas, the equation of state of ideal gases is simply the           law.

a.         A. Gay-Lussac law

b.         B. Dulong and Petit

c.         C. Avogadro’s

d.         D. Henry’s

82.       An ideal gas whose specific heats are constant is called

            .

a.         A. Perfect gas

b.         B. Natural gas

c.         C. Artificial gas

d.         D. Refined gas

83.       What are the assumptions of the kinetic gas theory?

a.         A. Gas molecules do not attract each other

b.         B. The volume of the gas molecules is negligible compared to the volume of the gas

c.         C. The molecules behave like hard spheres

d.         D. All of the above

84.       “The total volume of a mixture of non-reacting gases is equal to the sum of the partial volumes.” This statement is known as            .

a.         A. Law of Dulong and Petit

b.         B. Maxwell-Boltzmann law

c.         C. Amagat’s law

d.         D. Avogadro’s law

85.       An adiabatic process in which there is no change in system enthalpy but for which there is a significant decrease in pressure is called      .

a.         A. Isochoric process

b.         B. Isobaric process

c.         C. Throttling process

d.         D. Quasistatic process

86.       What is defined as the ratio of the change in temperature to the change in pressure when a real gas is throttled?

a.         A. Rankine coefficient

b.         B. Kelvin coefficient

c.         C. Maxwell-Boltzmann coefficient

d.         D. Joule-Thomson coefficient

87.       The low temperature reservoir of the heat reservoirs is known as  .

a.         A. Source reservoir

b.         B. Heel reservoir

c.         C. Toe reservoir

d.         D. Sink reservoir

88.       A          is a flow in which the gas flow is adiabatic and frictionless and entropy change is zero.

a.         A. Isentropic flow

b.         B. Isobaric flow

c.         C. Steady flow

d.         D. Uniform flow

 

e.         A. Burn temperature

f.          B. Kindle temperature

g.         C. Spark temperature

h.         D. Ignition temperature

89.       What law predicts the dew point of moisture in the fuel gas?

a.         A. Dalton’s law

b.         B. Law of Dulong and Petit

c.         C. Ringelman law

d.         D. Amagat’s law

90.       What law states that one energy from can be converted without loss into another form?

a.         A. Amagat’s law

b.         B. Joule’s law

c.         C. Lussac’s law

d.         D. Henry’s law

91.       Which is NOT a correct statement?

a.         A. A superheated vapor will not condense when small amount of heat re removed

b.         B. An ideal gas is a gas that is not a superheated vapor

c.         C. A saturated liquid can absorb as much heat as it can without vaporizing

d.         D. Water at 1 atm and room temperature is subcooled

92.       Thermodynamics is the study of heat and its transformation which stems from Greek words meaning            .

a.         a. transformation of heat

b.         b. transformation of energy

c.         c. movement of heat

d.         d. movement of matter

93.       What is the Si unit for temperature?

a.         a. Kelvin

b.         b. Celsius

c.         c. Fahrenheit

d.         d. Rankine

94.       The energy that flows from higher temperature object to a lower temperature object because of the difference in temperature is called

a.         a. heat

b.         b. temperature

c.         c. thermodynamics cycle

d.         d. energy flow

95.       The amount of heat energy per kilogram that must be added or removed when a substance changes from one phase to another.

a.         a. specific heat

b.         b. heat of expansion

c.         c. latent heat

d.         d. useful heat

96.       The change in physical size of a substance when its temperature changes.

a.         a. intensive property

b.         b. extensive property

c.         c. volume expansion

d.         d. thermal expansion absolute zero temperature.

e.         a. internal KE

 

97.       A stress which develops within an object when it attempts to expand or contract in response to a temperature changes, but cannot, due to being held rigidly in place.

a.         a. elongation

b.         b. thermal stress

c.         c. expansion contraction

d.         d. thermal expansion

98.       The energy associated with individual molecules in a gas, liquid or solid.

a.         a. Specific Energy

b.         b. Molecular Energy

c.         c. Internal Energy

d.         d. Phase Energy

99.       The heat Q per unit mass per degree change in temperature that must be supplied or removed to change the temperature of a substance.

a.         a. Specific Heat Capacity

b.         b. Latent Heat

c.         c. Heat of Transformation

d.         d. Internal Heat

100.     The pressure of the vapor phase of a substance that is in equilibrium with the liquid or solid phase.

a.         a. Phase Pressure

b.         b. Equilibrium Vapor Pressure

c.         c. Specific Pressure

d.         d. Equilibrium Phase Pressure

101.     Vapor pressure depends only on        .

a.         a. pressure

b.         b. force

c.         c. volume

d.         d. temperature

102.     A plot of pressure vs. temperature for a given substance showing the various phases possible for that particular substance.

a.         a. Phase diagram

b.         b. P-T diagram

c.         c. Wein Diagram

d.         d. Histogram

103.                is the grand total of all energies inside a substance.

a.         a. Internal Energy

b.         b. Grand Energy

c.         c. Atomic Energy

d.         d. Elemental Energy

104.     The      is defined as the amount of heat required to change the temperature of 1 gram of water by 1 Celsius degree.

a.         a. specific heat

b.         b. latent heat

c.         c. Joule

d.         d. calorie

105.                is a measure of the average kinetic energy per molecule in a substance.

a.         a. movement

b.         b. temperature

c.         c. heat

d.         d. mass

106.                the very small KE still present in molecules at

 

a.         b. Atomic kinetic energy

b.         c. Zero-Point Energy

c.         d. Subliminal Energy