Thermodynamics Past Paper PDF

THERMODYNAMICS 1.PAST ME BOARD QUESTION Enthalpy of an ideal gas is a function only of ________ A.Entropy B.Internal energy C.Temperature D.Pressure Answer : C 2. PAST ME BOARD QUESTION Which of the following is the most efficient thermodynamic cycle? A.Brayton B.Otto C.Carnot D.Diesel Answer:...

THERMODYNAMICS 1.PAST ME BOARD QUESTION Enthalpy of an ideal gas is a function only of ________ A.Entropy B.Internal energy C.Temperature D.Pressure Answer : C 2. PAST ME BOARD QUESTION Which of the following is the most efficient thermodynamic cycle? A.Brayton B.Otto C.Carnot D.Diesel Answer: C 3. PAST ME BOARD QUESTION What is the law of thermodynamics? A.Internal energy is due to molecular motion B.Entropy of the universe is increased by irreversible processes C.Energy can neither becreated nor destroyed D.Heat energy cannot be completely transformed into work Answer: C 4. PAST ME BOARD QUESTION An ideal gas is compressed isothermally.What is the enthalpy change? A.Always negative B.Always positive C.Zero D.Undefined Answer: C 5. PAST ME BOARD QUESTION Name the process that has no heat transfer. A.Isothermal B.Isobraic C.Polytropic D.Adiabatic Answer: D 6. PAST ME BOARD QUESTION An ideal gas is compressed in a cylinder so well insulated that there is essentially no heat transfer.The temperature of the gas. A.Decreases B.Increases C.Remain constant D.Is zero Answer: B 7. PAST ME BOARD QUESTION What is the Si unit of pressure?² A. Kg cm² B.Dynes cm² C. Pascal D. Psi Answer: C 8. PAST ME BOARD QUESTION The equation Cp=Cv+R applies to which of the following? A.Enthalpy B.Ideal gas C.Two phase states D.All pure substances Answer: B 9. PAST ME BOARD QUESTION In the flow process,neglecting kinetic and potential energy,the integral of Vdp represents what? A.Heat transfer B.Flow energy C.Enthalpy change D.Shaft work Answer: D 10. PAST ME BOARD QUESTION Mechanical energy of pressure tranformed into energy of heat. A.Kinetic energy B.Enthalpy C.Heat exchanger D.Heat of compression Answer: B 11. PAST ME BOARD QUESTION The theory of changing heat into mechanical work. A.Thermodynamics B.Kinematic C.Inertia D.Kinetics Answer: A 12. PAST ME BOARD QUESTION Average pressure on a surface when a changing pressure condition exist. A.Back pressure B.Partial C.Pressure drop D.Mean effective pressure Answer: D 13. PAST ME BOARD QUESTION Which of the following cycles consists two isothermal and two constant volume processes? A.Dieasel cycle B.Ericsson cycle C.Stirling cycle D.Otto cycle Answer: C 14. PAST ME BOARD QUESTION A control volume refers to what? A.A fixed region in space B.A reversible process C.An isolated system D.A specified mass Answer: A 15. PAST ME BOARD QUESTION In the polytropic process, PVⁿ=constant,if the value of n is infinitely large,the process is A.Isobaric B.Isometric C.Isothermal D.Polytropic Answer: B 16. PAST ME BOARD QUESTION If the temperature is held constant and the pressure is increased beyond the saturation pressure,then the working medium must be: A.Compressed liquid B.Subcooled liquid C.Saturated vapor D.Saturated liquid Answer: A 17. PAST ME BOARD QUESTION Is one whose temperature is below the saturation temperature corresponding to its pressure. A.Superheated vapor B.Wet vapor C.Subcooled liquid D.Saturated liquid Answer: C 18. PAST ME BOARD QUESTION Number of molecules in a mole of any substanceis a constant called________ A.Rankine constant B.avogadro’s number C.Otto constant D.Thompson constant Answer: B 19. PAST ME BOARD QUESTION If the pressure of a gas is constant the volume is directly proportional to absolute temperature. A.Boyle’s law B.Joule’s law C.Charle’s law D.Kelvin’s law Answer: C 20. PAST ME BOARD QUESTION The number of protons in the nucleus of an atom or the number of electrons in the orbitof an atom. A.Atomic volume B.Atomic number C.Atomic weight D.Atomic mass Answer: B 21. PAST ME BOARD QUESTION In a P-T diagram of a pure substance,the curve seperating the solid phase from the liquid phase is: A.Vaporization B.Fusion curve C.Boiling point D.Sublimation point Answer: B  23. PAST ME BOARD QUESTION The latent heat of vaporized in joules per kg is equal to _______ A.5.4 x 10² B.4.13 x 10³ C.22.6 x 105 D.3.35 x 10 Answer: C 24. PAST ME BOARD QUESTION From of energy associated with the kinetic energy of the random motion of large number of molecules A.Internal energy B.Kinetic energy C.Heat of fusion D.Heat Answer: D 25. PAST ME BOARD QUESTION If the temperature is held constant and the pressure is increased beyond the saturation pressure,then the working medium must be: A.Saturated vapor B.Compressed liquid C.Saturated liquid D.Subcooled liquid Answer: B 26. PAST ME BOARD QUESTION Is the condition of pressure and temperature at which a liquid and its vapor are indistinguishable. A.Critical point B.Dew point C.Absolute humidity D.Relative humidity Answer: A 27. PAST ME BOARD QUESTION When a substance in gaseous state is below the critical temperature it is called _________ A.Vapor B.Cloud C.Moisture D.Steam Answer: A 28. PAST ME BOARD QUESTION Superheated vapor behaves A.Just as gas B.Just a steam C.Just as ordinary vapo D.Approximately as a gas Answer: D 29. PAST ME BOARD QUESTION Which of the following provides the basis for measuring thermodynamic property of temperaturre? A.Zeroth law of thermodynamics B.First law of thermodynamics C.Second law of thermodynamics D.Third law of thermodynamics Answer: A 30. PAST ME BOARD QUESTION Which of the following is commonly used as liquid absorbent? A.Silica gel B.Activated alumina C.Ethylene glycol D.None of these Answer: C 31. PAST ME BOARD QUESTION Mechanism designed to lower the temperature of air passing through it. A.Air cooler B.Air defense C.Air spill over D.Air cycle Answer: A 32. PAST ME BOARD QUESTION A device for measuring the velocity of wind A.Aneroid barometer B.Anemometer C.Anemoscope D.Anemograph Answer: B 33. PAST ME BOARD QUESTION Heat normally flowing from a high temperature body to a low temperature body wherein it is impossible to convert heat without other effects. A.First law of thermodynamics B.Second law of thermodynamics C.Third law of thermodynamics D.Zeroth law of thermodynamics Answer: B 34. PAST ME BOARD QUESTION The temperature at which its vapor pressure is equal to the pressure exerted on the liquid. A.Absolute humidity B.Calorimetry C.Boiling point D.Thermal point Answer: C 35. PAST ME BOARD QUESTION A nozzle is used to A.Increase velocity and decreas pressure B.Decrease velocity as well as pressure C.Increase velocity as well as pressure D.Decrease velocity and increase pressure Answer: A 36. PAST ME BOARD QUESTION The sum of the energies of all the molecules in a sytem where energies appear in several complex form. A.Kinetic energy B.Potential energy C.Internal energy D.Frictional energy Answer: C 37. PAST ME BOARD QUESTION The total energy in a compressible fluid flowing across any section in a pipeline is a function of. A.Pressure and velocity B.Pressure,density and velocity C.Pressure,density,velocity and viscosity D.Flow energy,kinetic energy,height above datum and internal energy Answer: D 38.PAST ME BOARD QUESTION The ratio of the density of a substance to the density of some standard substance. A.Relative density B.Specific gravity C.Spcific density D.Relative gravity Answer:B 39. PAST ME BOARD QUESTION Is one whose pressure is higher than the saturation pressure corresponding to its temperature. A.Compressed liquid B.Saturated liquid C.Saturated vapo D.Super heated vapor Answer: A 40. PAST ME BOARD QUESTION The changing of solid directly to vapor without passing through the liquid state is called A.Evaporation B.Vaporization C.Sublimition D.Condensation Answer: C 41. PAST ME BOARD QUESTION Weight per unit volume is termed as ________ A.Specific gravity B.Density C.Weight density D.Specific volume Answer: C 42. PAST ME BOARD QUESTION What is the S1 unit of force? A.Pound B.Newton C.Kilogram D.Dyne Answer: B 43. PAST ME BOARD QUESTION The volume of fluid passing a cross-section of steam in unit time. A.Steady flow B.Uniform flow C.Discharge D.Continuous flow Answer: C 44. PAST ME BOARD QUESTION What equation applies in the first law of thermpdynamics for an ideal gas in a reversible open steady state system? A.Q-W=U2-U1 B.Q+VdP=H2-H1 C.Q-VdP=U2-U1 D.Q-PdV=H2-H1 Answer: B 45. PAST ME BOARD QUESTION A pressure of 1 millibar is equivalent to A.1000 dynes cm² B.1000 cm of Hg C.1000 psi D.1000 kg cm² Answer: A 46. PAST ME BOARD QUESTION When a system deviates infinitesimally from equilibrium at every instant of its state ,it is undergoing: A.Isobaric process B.quasi-static process C.Isometric process D.Cyclic process Answer: B 47. PAST ME BOARD QUESTION What is the force which tends to draw a body toward the center about which it is rotating? A.Centrifugal force B.Centrifugal in motion C.Centrifugal advance D.Centripetal force Answer: D 48. PAST ME BOARD QUESTION What is the process that has no heat transfer? A.Reversible isometric B.Isothermal C.Polytropic D.Adiabatic Answer: D 49. PAST ME BOARD QUESTION Which of the engine is used for fighter bombers? A.Turbojet B.Pulsejet C.Rockets D.Ramjet Answer: A 50. PAST ME BOARD QUESTION Exhaust gases from an engine posses A.Solar energy B.Kinetic energy C.Chemical energy D,stored energy Answer: B 51. PAST ME BOARD QUESTION At critical point the latent enthalpy of vaporization is A.Temperature dependent B.Zero C.Minimum D.Maximum Answer: B 52. PAST ME BOARD QUESTION What is the force which tends to draw abody toward the center about which it is ratating? A.Centrifugal force B. Centrifugal in motion C. Centrifugal advance D, Centripetal force Answer: D 53. PAST ME BOARD QUESTION When a system deviates infinitesimally from equilibrium at every instant of its state,it is undergoing A.Isobaric process B.quasi-static process C.Isometric process D.Cyclic process Answer: B 54. PAST ME BOARD QUESTION A pressure of 1 millibar is equivalent to A.1000 dynes/cm² B.1000 cm of Hg C.1000 psi D.1000 kg/cm² Answer: A 55. PAST ME BOARD QUESTION Work done per unit charge when changed is moved from one point to another A.Equipotential surface B.Potential at a point C.Electrostatic point D.Potential difference Answer: B 56. PAST ME BOARD QUESTION How many independent properties are required to completely fix the equilibrium state of a pure gaseous compound.? A.1 B.2 C.3 D.4 Answer: B 57. PAST ME BOARD QUESTION Which of the following relations defines enthalpy? A.h-u+p/t B.h=u+pV C.h=u+p/V D.h=pV+T Answer: B 58. PAST ME BOARD QUESTION Which of the following is true for water at a reference temperature where enthalpy is zero? A.Internal energy is negative B.Entropy is non –zero C.Pecific volume is zero D.Vapor pressure is zero Answer: A 59. PAST ME BOARD QUESTION On what plane is the mollier diagram plotted? A.p-V B.p-T C.h-s D.h-u Answer: C 60. PAST ME BOARD QUESTION The compressibility factor z,is used for predicting the bahavior of non ideal gases.How is the compressibility factor defined relative to an ideal gas?(subscript c refers to critical value.) A.z=P/Pc B.z=PV/RT C.z=T/Tc D.z=(T/Tc)(Pc/P) Answer: B 61. PAST ME BOARD QUESTION How is the quality x of a liquid vapor mixture defined? A.The fraction of the total volume that is saturated vapor B. A.The fraction of the total volume that is saturated liquid C. A.The fraction of the total mass that is saturated vapor D. A.The fraction of the total mass that is saturated liquid Answer: C 62.What is the expression for heat of vaporization? A.hg B.hf C.hg-hf D.hf-hg Answer: C 63.What is the value of the work done for a closed,reversible,isometric system? A.Zero B.Positive C.Negative D.Indeterminate Answer: A 64.What is the equation for the work done by a constant temperature system? A.W=mRT In (V2-V1) B.W=mR (T2-T1) In (V2/V1) C.W=MRT In (V2/V1) D.W=RT In (V2/V1) Answer: C  66.How does an adiabatic process compare to an isentropic process? A.Adiabatic: Heat transfer = 0 ,isentropic,Heat transfer = 0 B.Adiabatic: Heat transfer = 0 Isentropic:Heat transfer = 0 C.Adiabatic: Reversible,Isentropic:Not reversible D.Both:Heat transfer = 0:Isentropic:Reversible Answer: D 67.During an adiabatic,internally reversible process,what is true about the change in entropy? A.It is always zero B.It is always less than zero C.It is always graeter than zero D.It is temperature dependent Answer: A 68.For an irreversible process,what is true about the change in entropy of the system and surroundings? A.ds = dq dt B.ds = 0 C.ds > 0 D.ds < 0 Answer: C 69.For which type of process does the equation dQ = Tds hold? A.Irreversible B.Reversible C.Isobaric D.Isothermal Answer: B   71.Which of the following thermodynamic cycle is the most efficent? A. Brayon B. Rankine C. Carnot D. Otto Answer: C 72.The ideal reversible carnot cycle involves four basic processes.What type of processes are they? A.All isothermal B.All adiabatic C.All isentropic D.Two isothermal and two isentropic Answer: D  74.Which of the following is not an advantage of a superhead,closed rankine cycle over an open Rankine cycle? A.Lower equipment cost B.Increased efficiency C.Increased turbine life D.Increased boiler life Answer: D 75.Which of the following statements regarding Rankine cycle is not true? A.Use of a condensable vapor in the cycle increases the efficiency of the cycle. B.The temperatures at which energy is transferred to and form the working liquid are less seperated than in a Carnot cycle. C.Superheating increases the efficiency of a Rankine cycle. D.In practical terms the susceptibility of the engine materials to corrosion is not a key limitation on the operating efficiency Answer:D  77.A substance is oxidized when which of the following occurs? A.It turns red B.It loses electrons C.It gives off heat D.It absorbs energy Answer: B 78.Which of the following is not a unit of pressure? A.Pa B.kg m-s C.Bars D. Kg m² Answer: B 79.Which of the following is the definition of joule? A.Newton meter B. Kgm s² C.Unit of power D.Rate of change of energy Answer: A 80.Which of the following is the basis for Bernoulli’s law for fluid flow? A.The principle of conservation of mass B.The principle of conservation of energy C.The continuity equation D.fourier’s law Answer: B 81.Equation of state for a single component can be any of the following except: A.The ideal gas law B.Any relationship interrelating 3 or more state function C.Relationship mathematically interrelating thermodynamic properties of the material D.A mathematical expression defining a path between states Answer: D 82.The state of a thermodynamic system is always define by its: A.Absolute temperature B.Process C.Properties D.Temperature and pressure Answer: C 83.In any non quasi-static thermodynamics process,the overall entropy of an isolated system will A.Increase and then decrease B.Decrease and then increase C.Increase only D.Decreas only Answer: C 84.Entropy is the measure of: A.The internal energy of a gas B.The heat capacity of a substance C.Randomness or disorder D.The change of enthalpy of a system Answer: C 85.Which of the following statement about entropy is false? A.Entropy of a mixture is greater than that of its component under the same condition B.An irreversible process increases entropy of the universe C.Net entropy change in any closed cycle is zero D.Entropy of a crystal at 0°F is zero Answer: D 86.Work energy can be a function of all the following except: A.Force and distance B.Power and time C.Force and time D.Temperature and entropy Answer: C 87.Energy change are represented by all except which one of the following: A.mCpdt B.-ʃ VdP C.Tds – PdV D.dQ T Answer: D 88.U + pV is a quantity called: A.Shaft work B.Entropy C.Enthalpy D.Internal energy Answer: C 89.In flow process,neglecting KE and PE changes, ʃvdP represents which item below? A.Heat transfer B.Shaft work C.Enthalpy change D.Closed system work Answer: B 90.Power may be expressed in units of A.Ft – lb B.Kw – hr C.Btu D. Btu hr Answer: D 91.Equilibrium condition exist in all except which of the following? A.In reversible processes B.In processes where driving forces are infinitesimals C.In a steady state flow process D.Where nothing can occur without an effect on the system’s surrounding Answer: C 92.In a closed system (with a moving boundary)which of the following represents work done during an isothermal process? A. W = 0 B. W = P(V2-V1) C. W = P1V1 In V2 V1 D. W = P2V2-P1V1 1–n Answer: C 93.A substance that exist or is regarded as existing as a continuoum characterized by a low resistance to flow and the tendency to assume the shape of its container. A.Fluid B.Atom C.Molecule D.Vapo Answer: A 94.A substance that is homogenous in composition and homogenous and invariable in chemical aggregation. A.Pure substance B.Simple substance C.Vapo D.Water Answer: A 95.A substance whose state is defined by variable intensive thermodynamic properties. A.Pure substance B.Simple substance C.Vapor D.Water Answer: B 96.A system in which there is no exchange of matter with the surrounding or mass does not cross its boundaries. A.Open system B.Closed system C.Isolated system D.Nonflow system Answer: B 97.A system that is completely impervious to its surrounding or neither mass nor energy cross its boundaries. A.Open system B.Closed system C.Isolated system D.Nonflow system Answer: C 98.A system in which there is a flow of mass across its boundaries. A.Open system B.Closed system C.Isolated system D.Steady flow system Answer: A 99.The properties that are dependent upon the mass of the system and are total values such as total volume and total internal energy. A.Intensive properties B.Extensive properties C.Specific properties D.State properties Answer: B 100.The properties that are independent of the mass of the sysytem such as temperature,pressure,density and voltage. A.Intensive properties B.Expensive properties C. Specific properties D. State properties Answer: A 101.The properties for a unit mass and are intensive by definition such as specific volume. A.Intensive properties B.Extensive properties C.Specific properties D.Thermodynamic properties Answer: C 102.The condition as identified through the properties of the substance,generally defined by particular values of any two independent properties. A.State B.Point C.Process D.Flow Answer: A 103.The only base unit with a prefix kilo is A.Kilogram B.Kilometer C.Kilojoule D.Kilopascal Answer: A 104.The force of gravity on the body. A.Weight B.Specific gravity C.Attraction D.Mass Answer: A 105.The mass per unit volume of any substance. A.Density B.Specific volume C.Specific weight D.Specific gravity Answer: A 106.The force of gravity on unit volume is A.Density B.Specific volume C.Specific weight D.Specific gravity Answer: C 107.The reciprocal of density is A.Specific volume B. Specific weight C. Specific gravity D. Specific heat Answer: A 108.avogadro’s number ,a fundamental constant of nature is the number of molecules in gram mole This constant is A.6.05222x10²³ B.6.02252x10²³ C.6.20522x10²³ D.6.50222x10²³ Answer: B 109.The ratio of the gas constant to avogadro’s number is: A.maxwell’s constant B.boltzmann’z constant C.napier’s constant D.joule’s constant Answer: B  111.Absolute temperature on the fahrenheit scale are called: A.Degrees Rankine B.Degrees Kelvin C.Absolute Fahrenheit D.Absolute celcius Answer: A  113.What is the absolute temperature in celsius scale? A.Degrees Rankine B.Degrees Kelvin C.Absolute Fahrenheit D.Absolute celcius Answer: B 114.The fahrenheit scale was introduced by Gabriel Fahrenheit of Amstermdam,Holland in what year ? A.1592 B.1742 C.1730 D.1720 Answer: D 115.The centrigade scale was introduced by Andres Celcius in what year? A.1542 B.1740 C.1730 D.1720 Answer: B 116.The National Bureau of Standard uses,among others,the liquid vapor equilibrium of hydrogen at A.-196 °C B.196°C C.253 °C D,-253 °C Answer: A 117.The national Bureau of Standard uses among others,the liquid vapor equilibrium of nitrogen at A.-196 °C B.196°C C.253 °C D,-253 °C Answer: A 118.The liquid vapor equilibrium of oxygen is at what temperature? A.197.82 °C B.-197.82 °C C.182.97 °C D.-182.97 °C Answer: D 119.The solid liquid equilibrium of mercury is at what temperature? A.38.87 °C B.-38.87 °C C.37.88 °C D.-37.88 °C Answer: B 120.The solid liquid equilibrium of Tin is at what temperature? A.-38.87 °C B.38.87°C C.231.9 °C D.231.9 °C Answer: C 121.The solid liquid equilibrium of Zinc is at what temperature? A.231.9°C B.419.505°C C.444.60 °C D.630.5 °C Answer: B 122.The liquid vapor equilibrium of sulfur is at what temperature? A.231.9°C B.419.505°C C.444.60°C D.630.5°C Answer: C 123.The solid liquid equilibrium of Antimony is at what temperature? A.630.5°C B.419.505°C C.444.60°C D.231.9°C Answer: A 124.The solid liquid equilibrium of silver is at what temperature? A.630.5°C B.960.8°C C.1063°C D.1774°C Answer: B 125.The solid liquid equilibrium of gold is at what temperature? A.630.5°C B.960.8°C C.1063°C D.1774°C Answer: C 126.The solid liquid equilibrium of platinum is at what temperature? A.630.5°C B.960.8°C C.1063°C D.1774°C Answer: D 127.The solid liquid equilibrium of Tungsten is at what temperature? A.3730°C B.3370°C C.3073°C D.3037°C Answer: B 128.The device that measures temperature bay the electromotinve force. A.Thermometer B.Thermocouple C.electro-thermometer D.Thermoseebeck Answer: B 129.The emf is a function of the temperature difference between the junction a phenomenon called. A.Seebeck effect B.Stagnation effect C.Primming D.Electromotive force Answer:A 130.The device that measure temperature by the electromotive force called thermocouple was discovered by: A.Galileo B.Fahrenhiet C.Celsius D.Seebeck Answer: D 131.When two bodies isolated from other environment are in thermal equilibrium with a third body,two are in thermal equilibrium with each other. A.Zeroth law of thermodynamics B.First law of thermodynamics C.Second law of thermodynamics D.Third law of thermodynamics Answer: A 132.The total entropy of pure substance approaches zero as the absolute thermodynamics temperature approaches zero. A.Zeroth law of thermodynamics B.First law of thermodynamics C.Second law of thermodynamics D.Third law of thermodynamics Answer: D 133.If any one or more properties of as system change the system is said to have undergone a _______ A.Cycle B.Process C.Flow D.Control Answer: B 134.When a certain mass of fluid in a particular state passes through a series of processes and returns to its initial state it undergoes a: A.Revolution B.Rotation C.Process D.Cycle Answer: D 135.The term given to the collection of matter under consideration enclosed within a boundary. A.System B.Matter C.Environment D.Atoms Answer: A 136.The region outside the boundary or the space and matter external to a system: A.Ex – system B.Surrounding C.Matter D.Extension Answer: B 137.The true pressure measured above a perpect vacuum. A.Absolute pressure B.Gage pressure C.Atmospheric pressure D.Vacuum pressure Answer: A 138.The pressure measured from the level of atmospheric pressure by most pressure recording instrument like pressure gage and open ended manometer. A.Gage pressure B.Atmospheric pressure C.Barometer pressure D.Absolute pressure Answer: A 139.The pressure obtained from barometer reading A.Absolute pressure B.Gage pressure C.Atmospheric pressure D.Vacuum pressure Answer: C 140.It is a form of energy associated with the kinetic random motion of large number of molecules. A.Internal energy B.Kinetic energy C.Heat D.Enthalphy Answer: C 141.The heat needed to charge the temperature of the body without changing its phase. A.Latent heat B.Sensible heat C.Specific heat D.Heat transfer Answer: B 142.The heat needed by the body to change its phase without changing its temperature. A.Latent heat B.Sensible heat C.Specific heat D.Heat transfer Answer: A 143.The measure of the randomness of the molecules of a substance. A.Enthalpy B.Internal energy C.Entropy D.Heat Answer: C 144.The heat energy transferred to a substance at a constant pressure process is ________ A.Enthalpy B.Heat C.Internal energy D.Entropy Answer: A 145.It is the energy stored within the body A.Enthalpy B.Heat C.Internal energy D.Entropy Answer: C 146.A theoretically ideal gas which strictly follows Boyle’s law and Charle’s law of gases. A.Universal gas B.Perfect gas C.Combined gas D.Imperfect gas Answer: B 147.In a confined gas,if the absolute temperature is held constant,the volume is inversly proportional to the absolute pressure. A.Boyle’s law B.Charles law C.Dalton’s law D.Avogadro’s law Answer: A 148.In a confined gas if the absolute pressure is held constant the volume is directly proportional to the absolute temperature. A.Boyle’s law B.Charles law C.Dalton’s law D.Avogadro’s law Answer: B 149.The pressure exerted in a vessel by a mixture of gases is equal to the sum of the pressure that each separate gas would exert if it alone occupied the whole volume of the vessel. A.Boyle’s law B.Charles law C.Dalton’s law D.Avogadro’s law Answer: C 150.At equal volume at the same temperature and pressure conditions,the gases contain the same number of molecules. A.Boyle’s law B.Charles law C.Dalton’s law D.Avogadro’s law Answer: D 151.A process in which the system departs from equilibrium state only infinitesimally at every instant. A.Reversible process B.Irreversible process C.Cyclic process D.Quasi-static process Answer: C 152.A process which gives the same state/conditions after the system undergoes a series of processes. A.Reversible process B.Irreversible process C.Cyclic process D.Quasi-static process Answer: C 153.A thermodynamic system that generally serves as a heat source or heat sink for another system. A.Combustion chamber B.Heat reservior C.Heat engine D.Stirling engine Answer: B 154.A thermodynamic system that operates continuosly with only energy (heat and work) crossing its boundaries;its boundaries are impervios to the flow of mass. A.Heat engine B.Steady flow work C.Stirling engine D.Ericson engine Answer: A 155.A surface that is impervious to heat is A.Isothermal surface B.Adiabatic surface C.Isochori surface D.Isobaric surface Answer; B 156.One of the consequences of Einstein’s theory of relativity is that mass may be converted into energy and energy into mass the relation being given by the famous equation.E = mc².What is the value of the speed of light c? A.2.7797 x 1010cm/s B.2.9979 x 1010cm/s C.1.7797 x 1010cm/s D.2.9979 x 1010cm/s Answer: B 157.In the polytropic process we have pvⁿ = constant,if the value of n is infinitely large,the process is called. A.Constant volume process B. Constant pressure process C. Constant temperature process D.Adiabatic process Answer: A 158.The thermodynamic cycle used in a thermal power plants is : A.Ericson B.Brayton C.Joule D.Rankine Answer: D 159.For the same heat input and same compression ratio ; A.Both Otto cycle and diesel cycle are equaly efficient B.Otto cycle is less efficient than diesel cycle C.Efficient depends mainly on working substance D.None of the above is correct Answer: C 160.A heat exchanger process where in the product of pressure and volume remains constant called: A.Heat exchanger process B.Isentropic process C.Throttling process D.Hyperbolic process Answer: D 161.Which of the following provides the basis for measuring thermodynamic property of temperature? A.Zeroth law of thermodynamics B.First law of thermodynamics C.Second law of thermodynamics D.Third law of thermodynamics Answer: A 162.1 watt…. A.1 Nm/s B. 1 Nm/min C. 1 Nm/hr D.1 kNm/hr Answer : A 163.Under ideal conditions,isothermal,isobraic,isochoric and adiabatic proceses are; A.Dynamic processes B.Stable processes C.quasi-static processes D.Static processes Answer; C 164.Isentropic flow is A.Perfect gas floe B.Irreversible adiabatic flow C.Ideal fluid flow D.Reversible adiabatic flow Answer: D 165.Exhaust gases from an engine possess A.Solar energy B.Kinetic energy C.Chemical energy D.Stored energy Answer: B 166.The extension and compression of a helical spring is an example of what process? A.Isothermal cycle B.Thermodynamic process C.Adiabatic process D.Reversible process Answer: D 167.At critical point the latent enthalphy of vaporization is ________ A.Dependent on temperature B.Zero C.Minimum D.Maximun Answer: B 168.Which of the following relating is not applicable in a free expansion process? A.Heat supplied is zero B.Heat rejected is zero C.Work done is zero D.Change in temperatue Answer: D 169.The triple point of a substance is the temperature and pressure at which: A.The solid and liquid phases are in equilibrium B.The liquid and gaseous phase are in equilibrium C.The solid,liquid and the gaseous phase are in equilibrium D.The solid does not melt the liquid does not boil and the gas does not condense Answer: D 170.According to clausius statement A.Heat flows from hot sunbstance to cold substance unaided B.Heat cannot flow from cold substance to hot subsance C.Heat can flow from cold substance to hot substance with the aid of external work D.A and C Answer: D 171.A heat engine is supplied heat at rate of 30,000 J/s gives an output of 9kW.The thermal efficiency of the engine is _______ A.30% B.43% C.50% D.55% Answer: A 172.The RMS velocity of hydrogen gas at N.T.P is approximately _________ A.3838 m/s B.1839 m/s C.4839 m/s D.839 m/s Answer: B 173.Which of the following cycles has two isothermal and two constant volume processes? A.Joule cycle B.Diesel cycle C.Ericson cycle D.Stirling cycle Answer: D 174.”it is impossible to construct a heat engine that operates in a cycle and receives a given quantity of heat from a high temperature body and does an equal amonu of work”The above statement is known as; A.Gay Lussac’s law B.Kinetic theory C.Kelvin – Planck’s law D.Joule – Thomson’s law Answer: C 175.Fcr steam nozzle,which of the following ratios will have the value less than unity? A.(pressure at inlet)/(Pressure at outlet) B.Specific volume at inlet/(Specific volume at outlet) C.Temperature of steam at inlet/(Temperature of steam at outlet) D.None of the above Answer: B 176.A Bell Coleman cycle is a reversed A.Stirling cycle B.Brayton cycle C.Joule cycle D.Carnot cycle Answer: C 177.Ericson cycle consists of the following four processes: A.Two isothermal and two constant volume B.Two isothermal and two constant isentropic C. A.Two isothermal and two constant pressure D. A.Two adiabatic and two constant pressure Answer.C 178.A steam nozzle changes A.Kinetic energy into heat energy B.Heat energy into potential energy C.Potential energy into heat energy D.Heat energy into kinetic energy Answer: D 177.Ericson cycle consists of the following four processes: A.Two isothermal and two constant volume B.Two isothermal and two constant isentropic C. A.Two isothermal and two constant pressure D. A.Two adiabatic and two constant pressure Answer.C 178.A steam nozzle changes A.Kinetic energy into heat energy B.Heat energy into potential energy C.Potential energy into heat energy D.Heat energy into kinetic energy Answer: D 179.Which is not correct for calculating air standard efficiency? A.All processes are reversible B.Specific heat remains unchange at all temperature C.No account of the mechanism of heat transfer is cosidered D.Gases dissociate at higher temperatures Answer: D 180.According to pettlier Thomson effect; A.It is imposible to construct a heat engine that operates in a cycle and receives a given quantity of heat from a high temperature body and does an equal amount of worke B.It is impossible to construct a device that operates in a cycle and produces no effect other than the transfer of heat from a cooler body to hotter body C.When two dissimilar metals are heated at one end and cooled at other,e.m.f. that is developed is proportional to difference of temperature at two ends D.Work can’t be converted into heat Answer: D 181.In actual gases the molecular collision are: A.Plastic B.Elastic C.Inelastic D.Inplastic Answer: C 182.The Beatle-Bridgeman equation of state is quite accurate in cases of: A.All pressures above atmospheric pressure B.Densities less than about 0.8 times the critical density C.Near critical temperature D.None of the above Answer: B 183.Which of the following statement about Van der Waals equation is correct? A.It is valid for all pressures and temperatures B.It represents a straight line on PV versus V plot C.It has three roots of identical value at the critical point D.The equation is valid for dynamic gases only Answer: C 184.The Clapeyron’s equation is applicable to: A.1 system in equilibrium B.A hange of state C.A change of statewhen two phases are in equilibrium D.A change of state when water and water vapor are involved Answer: D 185.The vapor pressure is related to the enthalpy of vaporization by the ; A.Clausius – clay peyron’s equation B.Dalton’s law C.Raoult’s law D.Maxwell’s equation Answer:A 186.Solubility of gas in a liquid at small concentration can be represented by which law? A.Henry’s law B.Clasius - clay peyron’s equation C. Dalton’s law D. Raoult’s law Answer; A 187.A compound pressure gauge is used to measure: A.Complex pressures B.Variable pressures C.Average pressures D.Positive and negative pressures Answer ; D 188.Which of the engine is used for fighter bombers? A.Turboprop B.Turbojet C.Ramjet D.Pulsejet Answer: B 189.Past board question The thermal efficiency of gas vapor cycle as compared to steam turbine or gas turbine A.Greater than B.Less than C.Not comparable D.Equal Answer: A 190. Past board question The process in which heat energy is transferred to a thermal energy storage device is known as; A.Adiabatic B.Regeneration C.Intercooling D.Heat transfer Answer: B 191. Past board question The absolute zero in celsius cale is; A.100 B.0 C.-273 D.273 Answer: C 192. Past board question What is the temperature when water and vapor are in equivalent with the atmospheric pressure? A.Ice point B.Steam point C.Critical point D.Freezing point Answer: B 193. Past board question The temperature of a pure substance at a temperature of absolute zero is; A.Unity B.Zero C.Infinity D.100 Answer: B 194. Past board question When the number of reheat stage in a reheat cycle is increased,the average temperature; A.Increases B.Decreases C.Is constant D.Is zero Answer: A 195. Past board question A temperature measurement in an ordinary thermometer which has constant specifi humidity A.Critical temperature B.Dew point temperature C.Dry bulb temperature D.Wet bulb temperature Answer: B 196. Past board question In a closed vessel when vaporization takes place,the temperature rises.due to the rising temperature,the pressure increases until an equilibrium is established between the temperature and pressure.The temperature of equilibrium is called: A.Dew point B.Ice point C.Superheated temperature D.Boiling point Answer: D 197. Past board question When hot soup was served in a cup during dinner an engineer was so eager to drink it.Since it was hot,he added cubes of ice to ccol the soup and stirred it.He noticed that dew starts to form on the outermost surface of the cup.What is this temperature equal to? A.Superheated temperature B.Equal to zero C.Standard temperature D.Equal to air’s dew point temperature Answer: D 198. Is a measure of the energy that is no longer available to perform useful work within the current environment. A.Absolute entropy B. Absolute enthalpy C.Fugacity D.Molar value Answer: A 199.A graph of enthalpy versus entropy for steam. A.Mollier diagram B.Moody diagram C.Steam table D.Maxwell diagram Answer: A 200.The reaction of inertia in an accelerated body is called A.Kinetic reaction B.Endothermal reaction C.Kinematic reaction D.Dynamic reaction Answer: A 201.A Mollier chart of thermodynamic properties is shown in which of the following diagrams? A.T – S diagram B.P – V diagram C.h – S diagram D.p – h diagram Answer: C 202.The following are included in the first law of thermodynamics for closed system EXCEPT A.Heat transferred in and of the system B.Work done by or on the system C.Internal energy D.Kinetic energy Answer: D 203.All processes below are irreversible excetp one.Which one? A.Magnetization with hysteresis B.Elastic tension and releas of a steel bar C.Inelastic deformation D.Heat conduction Answer: B 204.The combination of conditions that best describes a thermodynamic process is given by which of the following ? I.Has successive states through which the system passes II.When reversed leaves no change in the system III.When reversed leaves no change in the system or the surroundings IV.States are passes through so quikly that the surroundings do not change A.I and II B.I and III C.I and IV D.I only Answer; D 205.PAST ME BOARD QUESTION The sum of the energies of all the molecules in a system where energies appear in several complex forms is the; A.Kinetic energy B.Potential energy C.Internal energy D.Frictional energy Answer; C 206. PAST ME BOARD QUESTION The Carnot refrigeration cycle inclueds all of the following process except: A.Isentropic expansion B.Isothermal heating C.Isenthalpic expansion D.Isentropic compression Answer: C 207. PAST ME BOARD QUESTION The maximum possible work that can be obtained a cycle operating between two reservoirs is found from A.Process irreversibility B.Availability C.Carnot efficiency D.Reversible work Answer: C 208. PAST ME BOARD QUESTION The following factors are necessary to define a thermodynamic cycle except A.The working substance B.High and low temperature reservoirs C.The time it takes to complete the cycle D.The means of doing work on the system Answer: C 209. PAST ME BOARD QUESTION All of the following terms included in the second law for open system except A.Shaft work B.Flow work C.Internal energy D.Average work Answer; D 210. PAST ME BOARD QUESTION The following terms are included in the first law of thermodynamics for open system except A.Heat transferred in and out of the system B.Work done by or in the system C.Magnetic system D.Internal system Answer: C 211. PAST ME BOARD QUESTION The following terms are included in the first law of thermodynamics for closed system except A.Heat transferred in and out of the system B.Work done by or on the system C.Internal energy D.Kinetic energy Answer; D 212. PAST ME BOARD QUESTION Which of the following statements about a path function is not true? A.On a p- v diagram,it can represent work done B.On a t – s diagram,it can represent heat transferred C.It is dependent on the path between states of thermodynamic equilibrium D.It represents values of p,v,t and s between states that are path functions Answer: D 213.A constant pressure thermodynamic process obeys: A.Boyle’s law B.Charles law C.Amagat law D.Dalton’s law Answer: B 214.The first and second laws of thermodynamics are: A.Continuity equations B.Momentum equations C.Boiling temperature D.Equation of state Answer: C 215.Represent the temperature an ideal gas will attain when it is brought to rest adiabatically A.Absolute zero temperature B.Stagnation temperature C.Boiling temperature D.Critical temperature Answer: B 216.Gauge pressure and absolute pressure differ from each other by. A.The system units B.Atmospheric pressure C.The size of the gauge D.Nothing they mean the same thing Answer: B 217.Each of the following are correct values of standard.Atmospheric pressure except; A.1,000 atm B.14,962 psia C.760 torr D.103 mm Hg Answer: D 218.All of the following are the properties of an ideal gas except: A.Density B.Pressure C.Viscosity D.Temperature Answer: C 219.Which of the following is not the universal gas constant? A.1545 ft-lb/bmol-°R B.8.314 J/mol.K C.8314 kj/mol.K D.8.314 kJ/kmol.K Answer: C 220.The following are all commonly qouted values of standard temperatures and pressure except: A.32°F and 14.696 psia B.273.15 K and 101.325 kPa C.0°C and 760 mm Hg D.0°F and 29.92 in Hg Answer: D 221.The variation of pressure in an isobraic process is; A.Linear with temperature B.Describe by the perfect gas law C.Inversely proportiona; to temperature D.Zero Answer: D 222.For liquid flow the enthalpy is the sum of internal energy and _________ A.Entropy B.Work flow C.Pressure D.Temperature Answer: B 223.A thermodynamic process whose deviation from equilibrium is infinitesimal at all times is ________ A.Reversible B.Isentropic C.In quasi – equilibrium D.Isenthalpic Answer: C 224.Which thermodynamics property best describe the molecular activity of a substance? A.Enthalpy B.Entropy C.Internal energy D.External energy Answer: C 225.Stagnation enthalpy represents the enthalpy of a fluid when it is brought to rest _________ A.Isometrically B.Adiabatically C.Isothermally D.Disobarically Answer: B 226.During stagnation process the kinetic energy of a fluid is converted to enthalpy which result in an ; A.Increase in the fluid specific volume B. Increase in the fluid in fluid pressure C. Increase in the fluid temperature and pressure D. Increase in the fluid temperature Answer: C 227.The properties of fluid at the stagnation in state are called _________ A.Stagnation property B.Stagnation phase C.Stagnation state D.Stagnation vapor Answer; D 228.All of the following are thermodynamic properties except ________ A.Temperature B.Pressure C.Density D.Modulus of elasticity Answer: D 229.A liquid boils when its vapor pressure equals A.The gage pressure B.The critical pressure C.The ambient pressure D.One standard atmosphere Answer: C 230.A system composed of ice and water at 0°C is said to be ;__________ A.A multiphase material B.In thermodynamic equilibrium C.In thermal equilibrium D.All of the above Answer: D 231.The heat of fusion of a pure substance is: A.The change in phase from solid to gas B.The change in phase from liquid to gas C.The energy released in a chemical reaction D.The energy required to melt the substance Answer: D 232.The heat of vaporization involves the change in enthalpy due to: A.The change in phase from solid to gas B.The change in phase from liquid to gas C.The energy released in a chemical reaction D.The change in phase from solid to liquid Answer: B 233.The heat of sublimation involves the change in enthalpy due to ______________ A.The change in phase from solid to gas B.The change in phase from liquid to gas C.The energy released in a chemical reaction D.The change in phase from solid to liquid Answer: A 234.A specific property A.Defines a specific variable (e.g.,temperature) B.Is independ of mass C.Is an extensive property multiplied by mass D.Is dependent of the phase of the substance Answer: A 235.A material’s specific heat can be defined as: A.The ratio of heat required to change the temperature of mass by a change in temperature B.Being different for constant pressure and constant temperature processes C.A function of temperature D.All of the above Answer: D 236.If a substance temperature is less than its saturation temperature ,the ubstance is: A.Subcooled liquid B.Wet vapor C.Saturated vapor D.Superheated vapor Answer: A 237.If a substance temperature is equal to its saturation temperature,the substance is a _________ A. A.Subcooled liquid B.Wet vapor C.Saturated vapor D.Superheated vapor Answer: C 238.If a substance’s temperature is greater than its saturation temperature,the substance is a __________ A. A.Subcooled liquid B.Wet vapor C.Saturated vapor D.Superheated vapor Answer: D 239.Critical properties refer to A.Extremely important properties, such as temperature and pressure B.Heat required for phase change and important for energy production C.Properties values where liquid and gas phase are indistinguishable D.Properties having to do with equilibrium conditions,such as the Gibbs and Helmholtz function Answer: C 240.For a saturated vapor,the relationship between temperature and pressure is given by. A.The perfect gas law B.Van der Waal’s equation C.The steam table D.A Viral equation of state Answer: C 241.Properties of a superhested vapor are given by A.The perfect gas law B.A superheated table C.A one to one relationship,uch as the properties of saturated steam D.A viiral equation of state Answer: B 242.Properties of non reacting gas mixture are given by: A.Geometric weighting B.Volumetric weighting C.Volumetric weighting for malecular weight and density and geometric weighting for all other properties execpt entropy D.Arithmetic average Answer: C 243.The relationship between the total volume of a mixture of non reaching gases and their partial volume is given by ; A.Gravimetric fractions B.Amargat’s law C.Dalto’s law D.Mole fraction Answer: B 244.The relationship between the total pressure of a mixture of non reacting gases and the partial pressures of constituents is given by : A.Gravimetric fraction B.Volumetric fraction C.Dalton’slaw D.Mole fractions Answer: C 245.Which of the following is the best definition of enthalpy? A.The ratio of heat added to the temperature increases in a system B.The amount of useful energy in a system C.The amount of energy no longer available to the system D.The heat required to cause a complete convention between two phases at a constant temperature Answer: B 246.Which of the following statement is not true real gases? A.Molecules occupy a volume not negligible in comparison to the total volume of gas B.Real gases are subjected to attractive forces between molecules (e.g Van der Waals forces) C.The law of corresponding states may be used for real gases D.Real gases are found only rarely in nature Answer: D 247.The stagnation state is called the isentropic stagnation state when the stagnation process is ; A.Reversible as well dynamic B.Isotropic C.Adiabatic D.Reversible as well as adiabatic Answer: D 248.The entropy of a fluid remainsn constant during what process? A.Polytropic stagnation process B.Unsteady stagnation process C.Combustion process D.Isentropic stagnation process Answer ; D 249.All of the following processes are irreversible except A.Stirring of a viscous fluid B.An isentropic deceleration of a moving perfect fluid C.An unrestained expansion of a gas D.Phase changes Answer: B 250.All of the following processes are irreversible except A.Chemical reaction B.Diffusion C.Current flow through an electrical resistance D.An isentropic compression of a perfect gas Answer: D 251.All of the following processes are irreversible except ; A.Magnetization with hysteresis B.Elastic tension and releas of a steel bar C.Inelastic deformation D.Heat conduction Answer: B 252.Which of the following state(s) is/are necessary for a system to be in thermodynamic equilibrium? A.Chemical equilibrium B.Thermal equilibrium C.Mechanical equilibrium D.chemical,mechanical,and thermal equilibrium Answer: D 253.Adiabatic heat transfer within a vapor cycle refers to A.Heat transfer that is atmospheric but not reversible B.The transfer of energy from one steam to another in a heat exchanger so that the energy of the input streams equal the energy of the output stream. C.Heat transfer that is reversible but not isentropic D.There is no such thing as adiabatic heat transfer Answer: B 254.PAST ME BOARD QUESTION Which of the following gives polytropic under n? log P2 P1 A. V1 log V2 log P1 P2 B. V1 log V2 log P2 P1 C. V1 loV2 log P2 P1 D.. V1 log V2 Answer: A 255.PAST ME BOARD QUESTION The workdone in a adiabatic process in a system: A.Is equal to the change in total energy in a closed system B.Is equal to the total net heat transfer plus the entropy change C.Is equal to the change in total energy of closed system plus the entropy change D.Is equal to the change in total energy of closed system plus net heat transfer Answer: D 256. PAST ME BOARD QUESTION Based on the first law of thermodynamics which of the following is wrong? A.The heat transfer equals the work plus energy change B.The heat transfer cannot exceed the work done C.The net transfer equal the net work of the cycle D.The net heat transfer equals the energy change if no works is done Answer: B 257. PAST ME BOARD QUESTION Assuming real processes the entropy changein the universe: A.Must be calculated B.Equals zero C.Is negative D.Is positive Answer ; D 258. PAST ME BOARD QUESTION Which of the following types of flowmeters is most accurate? A.Venturi tube B.Pilot tube C.Flow nozzle D.Foam type Answer : B 259. PAST ME BOARD QUESTION What is referred by control volume? A.An isolated system B.Closed system C.Fixed region in space D.Reversible process only Answer : C 260. PAST ME BOARD QUESTION What is the most efficient thermodynamic cycle? A.Carnot B.Diesel C.Rankine D.Brayton Answer: A 261. PAST ME BOARD QUESTION How do you treat a statement that is considered a scientific law? A.We postulate to be true B.Accept as a summary of experimental observation C.We generally observed to be true D.Believe to be derived from mathematical theorem Answer: B 262.ME BOARD QUESTION An instrument commonly used in most research and engineering laboratories because it is small and fast among the other thermometers A.Mercury thermometer B.liquid-in-glass thermometer C.Gas thermometer D.Thermocouple Answer: D 263. PAST ME BOARD QUESTION In an actual gases,the molecular collision are A.Plastic B.Elastic C.Inelastic D.Inplastic Answer: C 264. PAST ME BOARD QUESTION Which of the following is used in thermal power plant? A.Brayton B.Reversed carnot C.Rankine D.Otto Answer: C 265. PAST ME BOARD QUESTION The elongation and compression of a helical spring is an example of A.Irreversible process B.Reversible process C.Isothernal process D.Adiabatic process Answer: B 266. PAST ME BOARD QUESTION Otto cycle consist of A.Two isentropic and two constant volume processes B.Two isentropic and two constant pressure processes C.Two adiabatic and two isothermal process D.Two isothermal and two constant volume processes Answer: A 267. PAST ME BOARD QUESTION Brayton cycle has A.Two isentropic and two constant volume processes B.Two isentropic and two constant pressure processes C.One constant pressure,one constant volume and two adiabatic processes D.Two isothermal,one constant volume and one constant pressure processes Answer: B 268. PAST ME BOARD QUESTION A bell coleman cycle is a reversed A.Stirling cycle B.Joule cycle C.Carnot cycle D.Otto cycle Answer; B 269. PAST ME BOARD QUESTION A steamnozzle changes A.Kinetic energy into heat energy B.Heat energy into potential energy C.Heat energy into kinetic energy D.Potential energy into heat energy Answer: C 270. PAST ME BOARD QUESTION The pitot tube is a device used for measurement of A.Pressure B.Flow C.Velocity D.Discharge Answer: C 271. PAST ME BOARD QUESTION The continuity equation is application to A.viscous,unviscous fluids B.Compressibility of fluids C.Conservation of mass D.Steady unsteady flow Answer: C 272. PAST ME BOARD QUESTION The work done by a force of R Newtons moving in a distance of L meters is converted entirely into kinetic energy and expressed by the equation: A.RL = 2MV² B.RL = 2MV C.RL = ½ MV² D.RL = ½ MV Answer;C 273. PAST ME BOARD QUESTION Gas being heated at constant volume is undergoing the process of ; A.Isentropic B.Adiabatic C.Isometric D.Isobaric Answer; C 274. PAST ME BOARD QUESTION Dew point is defined as. A.The temperature towhich the air must be cooled at constant pressure to produce saturation B.The point where the pressure and temperature lines meet. C.The temperature which dew is formed in the air D.The pressure which dew is formed in the air Answer: A 275. PAST ME BOARD QUESTION What do you call the changing of an atom of element into an atom of a different element with a different atomic mass? A.Atomization B.Atomic transmutation C.Atomic pile D.Atomic energy Answer: B 276. PAST ME BOARD QUESTION What do you call the weight of the column of air above the earth’s surface A.Air pressure B.Aerostatic pressure C.Wind pressure D.Atmospheric pressure Answer: D 277. PAST ME BOARD QUESTION What keeps the moisture from passing through the system? A.Dehydrator B.Aerator C.Trap D.Humidifier Answer: A 278. PAST ME BOARD QUESTION What condition exist in an adiabatic throttling proces? A.Enthalpy is variable B.Enthalpy is constant C. Entropy is constant D.Specific volume is constant Answer: B 279. PAST ME BOARD QUESTION The specific gravity of a substance is the ratio of its density to the density of; A.Mercury B.Gas C.Air D.Water Answer: D 280. PAST ME BOARD QUESTION A compound pressure gauge is used to measure A.Complex pressure B.Variable pressure C.Compound pressure D.Positive and negative pressure Answer: D 281. PAST ME BOARD QUESTION Isentropic flow is A.Perfect gas flow B.Ideal gas law C.Frictional reversible flow D.Reversible adiabatic flow Answer: D 282. PAST ME BOARD QUESTION Under ideal conditions,isothermal,isobaric,isochoric and adiabatic processes are ; A.Dynamic processes B.Stable processes C.quasi-static processes D.Static processes Answer: C 283. PAST ME BOARD QUESTION One watt is : A.1 N.m s B.1 N.m min C.1 N.m hr D.1 kN.m s Answer ; A 284.A temperature above whicha given gas cannot be liquefied: A.Cryogenic temperature B.Vaporization temperature C.Absolute temperature D.Critical temperature Answer: D 285. PAST ME BOARD QUESTION The effectiveness of a body as a thermal radiator at a given temperature. A.Absorption B.Emissivity C.Conductivity D.Reflectivity Answer: B 286. PAST ME BOARD QUESTION Which of the following occurs in a reversible polytropic process? A.Enthalpy remains constant B.Internal energy does not change C.Some heat transfer occurs D.Entropy remains constant Answer: C 287.ME Board Oct.1997 The instrument used to measure atmospheric pressure is: A.Rotameter B.Manometer C.Venturi D.Barometer Answer: D 288. ME Board Oct.1997 A pneumatic tool is generally powered by A.Water B.Electricity C.Steam D.Air Answer: D 289. PAST ME BOARD QUESTION Which of the following gases can be used to measure the lowest temperature? A.Nitrogen B.Helium C.Oxygen D.Hydrogen Answer: B 290. PAST ME BOARD QUESTION The triple point of a substance is the temperature and pressure at which: A.The solid and liquid phase are in equilibrium B.The solid and gaseous phase are in equilibrium C.The solid,liquid and gaseous phase are in equilibrium D.The solid does not melt,the liquid does not boil and the gas does not condense Answer: D 291. PAST ME BOARD QUESTION Which of the following relation is not application in a free expansion process? A.Heat rejected is zero B.Work done is zero C.Change in temperature is zero D.Heat supplied is zero Answer: C 292. PAST ME BOARD QUESTION Ericsson cycle has A.Two isothermal and two constant pressure processes B.Two isothermal and two constant entropy processes C. A.Two isothermal and two constant entropy process D.Two adiabatic.one constant volume and constant pressure processes. Answer; A 293. PAST ME BOARD QUESTION A stirling cycle has A.Two adiabatic and two constant volume processes B.Two adiabatic and two constant pressure processes C.Two isothermal and two constant pressure processes D.Two isothermal and two constant volume processes Answer: D 294. PAST ME BOARD QUESTION The temperature of the fluid flowing under pressure through a pipe is usually measured by ; A.A glass thermometer B.An electric resistance thermometer C.A thermacouple D.All of the above Answer: D  295. PAST ME BOARD QUESTION Specific heat capacity is an SI derived unit describe as A. J kg B. W mK C. kJ kgK D. J m Answer: C 296. PAST ME BOARD QUESTION Which of the following is mathematically a thermodynamic property? A.A point function B.Discountinous C.A path function D.Exact different Answer: A 297. PAST ME BOARD QUESTION When the expansion or compression of gas takes place without transfer of heat to or from the gas process is called: A.Reversible B.Adiabatic C.Polytropic D.Isothermal Answer: B 298. PAST ME BOARD QUESTION Another name for the liquid valve is: A.Freon valve B.Shut off valve C.King valve D.Master valve Answer: C 299. PAST ME BOARD QUESTION A liquid whose temperature is lower than the saturation temperature corresponding to the existing pressure: A.Subcooled liquid B.Saturated liquid C.Pure liquid D.Compressed liquid Answer: A 300. PAST ME BOARD QUESTION The law that state “Entropy of all perfect crystalline solids is zero at absolute zero temperature: A.Zeroth law of thermodynamics B.First law of thermodynamics C.Second law of thermodynamics D.Third law of thermodynamics Answer: D 301. PAST ME BOARD QUESTION What should be the temperature of both water and steam whenever they are present together? A.Saturation temperature for the existing pressure B.Boiling point of water at 101.325 kPa C.Superheated temperature D.One hundred degrees centigrade Answer: A 302. PAST ME BOARD QUESTION A manometer is an instrument that is used to measure: A.Air pressure B.Heat radiation C.Condensate water level D.Air volume Answer: A 303. PAST ME BOARD QUESTION What is thearea under the curve of a temperature entropy diagram? A.Volume B.Heat C.Work D.Entropy Answer: B 304. PAST ME BOARD QUESTION What do bodies at a temperature above absolute zero emit? A.Energy B.Heat of convection C.Thermal radiation D.Heat of compression Answer: C 305. PAST ME BOARD QUESTION In the absence of any irreversibillities,a thermoelectric generator,a device that incorporates both thermal and electric effects,will have the efficiency of a/an A.Carnot cycle B.Otto cycle C.Diesel cycle D.Rankine cycle Answer: A 306. PAST ME BOARD QUESTION Both stngines and ericson engines are A.Internal combustion engines B.External combustion engines C.Carnot engines D.Brayton engines Answer: B 307. PAST ME BOARD QUESTION Nozzles does not involve any work interaction.The fluid through this device experience: A.No change in pottential energy B.No change in kinetic energy C.No change in enthalpy D.Vacuum Answer: A  308. PAST ME BOARD QUESTION If the actual kinetic energy of a nozzle is Ka and Ki is the maximum value that can be attained by an isentropic expansionfrom an initial to final state,then the efficieny of the nozzle is: A. Ki Ka B. Ka-Ki Ka C. Ka-Ki Ki D. Ka Ki Answer: D 309. PAST ME BOARD QUESTION The convertion section of a nozzle increases the velocity of the flow of the gas.What does it to do on its pressure? A.Pressure becomes constant B.Pressure equals the velocity C.It increases the pressure D.It decreases the pressure Answer: D 310. PAST ME BOARD QUESTION In closed vessel,when vaporization takes place,the temperature rises.Due to the rising temperature,the pressure increases until an equilibrium is established between the temperature and pressure.The temperature of equilibrium is called _____ A.Dew point B.Ice point C.Boiling point D.Superheated temperature Answer: C 311. PAST ME BOARD QUESTION At steam point the temperatures of water and its vapor at standard pressure are: A.Extremes or maximum B.Unity C.In equilibrium D.Undefined Answer: C 312. PAST ME BOARD QUESTION When hot soup was served in a cup during dinner,an engineer was so eager to drink it.Since it was hot,he added cubes of ice to cool the soup and stirred it.He noticed that dew start to form on the outermost surface of the cup,He wanted to check the temperature of the outermost surfaceof the cup.What is this temperature equal to? A.Superheated temperature B.Equal to zer C.Standard temperature D.Equal to air’s dew point temperature Answer: D 313. PAST ME BOARD QUESTION What do you call a conversion technology that yields electricity straight from sunlight without the aid of a working substance like gas or steam without the use of any mechanical cycle? A.Power conversion B.Stirling cycle conversion C.Solar thermal convertion D.Photovoltaic energy convertion Answer: D 314. PAST ME BOARD QUESTION Which of the following property of liquid extend resistance to angular or shear deformation: A.Specific gravity B.Specific weight C.Viscosity D.Density Answer: C 315. PAST ME BOARD QUESTION What is the pressure at the exit of a draft tube in a turbine? A.Below atmospheric B.Above atmospheric C. Atmospheric D.Vacuum Answer: C 316. PAST ME BOARD QUESTION When change in kinetic energy of a compressed gas are negligible or insignificant,the work input to an adiabatic compressor is _______ A.Negligible B.Zero C.Infinity D.Equal to change in enthalpy Answer: D 317. PAST ME BOARD QUESTION What is the area under the curve of a pressure volume diagram? A.Nonflow work B.Steady work C.Heat D.Power Answer: A 318. PAST ME BOARD QUESTION In Stirling and Ericson cycle,regeneration can A.Increase efficiency B.Decrease efficiency C.Control efficiency D.Limit efficiency Answer: A 319. PAST ME BOARD QUESTION The first law of thermodynamics is based on which of the following principles? A.Conservation of mass B.Enthalpy entropy relationship C.Entropy temperature relationship D.Conversation of energy Answer: D 320. PAST ME BOARD QUESTION In two phase system,30% moisturemeans A.70% liquid and 30% vapor B.70% liquid and 30% liquid C.30% liquid and 100% vapor D30% vapor and 100% liquid Answer: B 321.Me Board Apr.2002 At 101.325kPa,the boiling point of water is 100°C.if the pressure is decreased,the boiling temperature will: A.Increas B.Decreas C.Remain the same D.Drop to zero Answer: B 322. PAST ME BOARD QUESTION Which of the following is equivalent to 1hp in Btu/hr? A.778 B.2545 C.746 D.3.41 Answer: B 323. PAST ME BOARD QUESTION What is the pressure above zero? A.Gage pressure B.Absolute pressure C.Vacuum pressure D.Atmospheric pressure Answer: A 324. PAST ME BOARD QUESTION One Newton – meter is equal to : A.1 Joule B.1 Btu C.1 Calorie D.1 ergs Answer: A 325. PAST ME BOARD QUESTION Which of the following is the instrument used to measure fluid velocity? A.Pitot tube B.Orsal apparatus C.Anemometer D.Viscosimeter Answer: A 326. PAST ME BOARD QUESTION Cryogenic temperature ranges from: A.-150°F to -359°F B. -250°F to -459°F C.-100°F to -300°F D.-200°F to -400°F Answer:B 327. PAST ME BOARD QUESTION Steam at 2 kPa is saturated at 17.5 °C.in what state will the state be at 40°C if the pressure is 2.0 kPa? A.Superheated B.Saturated C.Subcooled D.Supersaturated Answer: A 328. PAST ME BOARD QUESTION Acceleration is proportional to force. A.Newtons law B.Archimendes principle C.Law of gravitation D.Theory of relativity Answer: A 329. PAST ME BOARD QUESTION Which of the following could be defined as simply push and pull? A.Power B.Inertia C.Work D.Force Answer; D 330. PAST ME BOARD QUESTION The true pressure measured aboved a perfect vacuum is: A.Absolute pressure B.Atmospheric pressure C.Gauge pressure D.Vacuum pressure Answer: A 331. PAST ME BOARD QUESTION If an initial volume of an ideal gas is compressed to one half its original volume and to twice its original temperature the pressure: A.Doubles B.Halves C.Quadruples D.Triples Answer: C 332. PAST ME BOARD QUESTION When the expansion or compression of gas takes place without transfer of heat to or from the gas,the process is called: A.Isometric process B.Isothermal process C.Isobaric process D.Adiabatic process Answer: D 333. PAST ME BOARD QUESTION A body radiates heat proportional to the fourth power of its absolute temperature: A.Stefan – Boltzmann law B.Planck’s law C.Kirchhoff’s law D.Maxwell’s law Answer: A 334.All substance emit radation,the quantity and quality of which depends upon the absolute temperature and the properties of the material,composing the radiating body. A.Stefan – Boltzmann law B.Planck’s law C.Kirchhoff’s law D.Maxwell’s law Answer: B 335.For bodies in thermal equilibrium with their environment the ratio of total emissive power to the absorption is constant at any temperature. A.Stefan – Boltzmann law B.Planck’s law C.Kirchhoff’s law D.Maxwell’s law Answer: C