Railways NTPC (Technical Ability) Thermodynamics Question Bank

done Thermodynamics Total Questions - 120

• question_answer1)
  A reversible engine receives heat from a reservoir at \[700{}^\circ C\] and rejects heat at a temperature\[{{T}_{2}}\]. A second reversible engine operating on Carnot cycle receives heat rejected by the first engine and rejects heat to a sink at \[37{}^\circ C.\] If work output from each of the engines is equal, what is the value of temperature \[{{T}_{2}}\] ?
  A)
  641.5 K             done clear
  B)
  537 K done clear
  C)
  516 K                done clear
  D)
  498.5 K done clear
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• question_answer2)
    According to the Maxwell relation, which of the following is/arc correct?
  A)
  \[{{\left( \frac{\partial v}{\partial T} \right)}_{p}}=-\,{{\left( \frac{\partial s}{\partial p} \right)}_{T}}\]         done clear
  B)
  \[{{\left( \frac{\partial s}{\partial v} \right)}_{p}}={{\left( \frac{\partial p}{\partial T} \right)}_{v}}\] done clear
  C)
  \[{{\left( \frac{\partial P}{\partial T} \right)}_{v}}={{\left( \frac{\partial p}{\partial s} \right)}_{v}}\]            done clear
  D)
  All of the above done clear
  View Solution play_arrow

• question_answer3)
  Which one of the following relationships defines Gibbs' free energy G?
  A)
  \[G=H+TS\]                  done clear
  B)
  \[G=H-TS\] done clear
  C)
  \[G=U+7S\]                  done clear
  D)
  \[G=U-TS\] done clear
  View Solution play_arrow

• question_answer4)
  Consider the following statements:

  1. Two reversible adiabatics can never intersect each other.

  2. for a thermodynamic process \[\frac{dQ}{T}+1\ge 0,\] where I is the measure of irreversibility.

  Which of the statements given above is/are correct?
  A)
  1 only               done clear
  B)
  2 only done clear
  C)
  Both 1 and 2                  done clear
  D)
  neither 1 nor 2 done clear
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• question_answer5)
  Constant pressure lines in the superheated region of the Mother diagram have what type of slope?
  A)
  A positive slope done clear
  B)
  A negative slope done clear
  C)
  Zero slope done clear
  D)
  May have either positive or negative slope. done clear
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• question_answer6)
  Which one of the following is the extensive property of a thermodynamic system?
  A)
  Volume             done clear
  B)
  Pressure done clear
  C)
  Temperature                   done clear
  D)
  Density done clear
  View Solution play_arrow

• question_answer7)
  Which one of the following is the correct statement? Steam is said to be superheated when the
  A)
  Actual volume is greater than volume of saturated steam done clear
  B)
  Actual volume is less than volume of saturated steam done clear
  C)
  Actual volume is equal to volume of saturated steam done clear
  D)
  None of the above done clear
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• question_answer8)
  If \[{{M}_{1}}\,,\] \[{{M}_{2}}\,,\] \[{{M}_{3}}\] be molecular weight of constituent gases and \[{{m}_{1}},\] \[{{m}_{2}},\] \[{{m}_{3}},....\] their corresponding mass fractions, then what is the molecular weight M of the mixture equal to?
  A)
  \[{{m}_{1}}\,{{M}_{1}}+{{m}_{2}}\,{{M}_{2}}+{{m}_{3}}\,{{M}_{3}}+...\] done clear
  B)
  \[\frac{1}{{{m}_{1}}\,{{M}_{1}}+{{m}_{2}}\,{{M}_{2}}+{{m}_{3}}\,{{M}_{3}}+...}\] done clear
  C)
  \[\frac{1}{{{m}_{1}}\,{{M}_{1}}}+\frac{1}{{{m}_{2}}\,{{M}_{2}}}+\frac{1}{{{m}_{3}}\,{{M}_{3}}}+...\] done clear
  D)
  \[\frac{1}{\left( \frac{{{m}_{1}}}{{{M}_{1}}} \right)+\left( \frac{{{m}_{2}}}{{{M}_{2}}} \right)+\left( \frac{{{m}_{3}}}{{{M}_{3}}} \right)+...}\] done clear
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• question_answer9)
  If a gas obeys van-der Waals' equation at the critical point, then \[\frac{R\,{{T}_{c}}}{{{p}_{c}}\,{{v}_{c}}}\] is equal to which one of the following?
  A)
  0                                  done clear
  B)
  1 done clear
  C)
  1.5                                done clear
  D)
  2.67                 done clear
  View Solution play_arrow

• question_answer10)
  Which one of the following is the correct statement? Two adiabatics will
  A)
  Intersect at absolute zero temperature         done clear
  B)
  Never intersect                              done clear
  C)
  Become orthogonal at absolute zero temperature done clear
  D)
  Become parallel at absolute zero temperature done clear
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• question_answer11)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Irreversibility	1.	Mechanical equivalent
  B.	Joule-Thomson experiment	2.	Thermodynamic temperature scale
  C.	Joule?s experiment	3.	Throttling process
  D.	Reversible engine	4.	Loss of availability

  Codes:
  A)
  A\[\to \]1, B\[\to \]2, C\[\to \]3, D\[\to \]4 done clear
  B)
  A\[\to \]1, B\[\to \]2, C\[\to \]4, D\[\to \]3 done clear
  C)
  A\[\to \]4, B\[\to \]3, C\[\to \]2, D\[\to \]1 done clear
  D)
  A\[\to \]4, B\[\to \]3, C\[\to \]1, D\[\to \]2 done clear
  View Solution play_arrow

• question_answer12)
  For air standard Brayton cycle, increase in the maximum temperature of the cycle, while keeping the pressure ratio the same, would result in:
  A)
  Increase in air standard efficiency done clear
  B)
  Decrease in air standard efficiency done clear
  C)
  No change in air standard efficiency          done clear
  D)
  Increase in the efficiency but reduction in network done clear
  View Solution play_arrow

• question_answer13)
  Which one of the following cycles working within the same temperature limits has the highest work ratio?
  A)
  Carnot cycle                   done clear
  B)
  Joule cycle        done clear
  C)
  Otto cycle                      done clear
  D)
  Rankine cycle. done clear
  View Solution play_arrow

• question_answer14)
  The equation of state \[pv=R\,T\,\,(1+{B}/{v+{C}/{{{v}^{2}}+{D}/{{{v}^{3}}+...)}\;}\;}\;\] is known as:
  A)
  Van der Waals equation done clear
  B)
  Benedict-Webb-Rubin equation done clear
  C)
  Gibbs equation done clear
  D)
  Virial equation. done clear
  View Solution play_arrow

• question_answer15)
  What is the ratio of the slopes for p?v curves for an adiabatic process and an isothermal process?
  A)
  \[{1}/{\gamma }\;\]                                done clear
  B)
  \[\gamma +1\] done clear
  C)
  \[\gamma \]                                done clear
  D)
  \[\frac{1}{\gamma +1}\] done clear
  View Solution play_arrow

• question_answer16)
  Match List-I (Thermodynamic system/prime mover) with List-II (Thermodynamic cycle) and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Air liquefaction plant	1.	Atkinson cycle
  B.	Gas turbine with multistage compression and multistage expansion	2.	Brayton cycle
  C.	Free piston engine/compressor with a gas turbine	3.	Ericsson cycle
  D.	Pulse jet	4.	Reversed Stirling cycle
  		5.	Lenoir cycle

  Codes:
  A)
  A\[\to \]1, B\[\to \]2, C\[\to \]4, D\[\to \]3 done clear
  B)
  A\[\to \]1, B\[\to \]2, C\[\to \]3, D\[\to \]4 done clear
  C)
  A\[\to \]4, B\[\to \]3, C\[\to \]1, D\[\to \]5 done clear
  D)
  A\[\to \]4, B\[\to \]3, C\[\to \]5, D\[\to \]1 done clear
  View Solution play_arrow

• question_answer17)
  What is the molecular weight (approximate) for the gas whose specific heats are as follows? \[{{c}_{p}}=1.967\,\,kJ/kg\,\,K\,;\]          \[{{c}_{v}}=1.507\,\,kJ/kg\,\,K\,\,\]
  A)
  17                                 done clear
  B)
  18 done clear
  C)
  19                                 done clear
  D)
  20 done clear
  View Solution play_arrow

• question_answer18)
  Consider the following statements:

  The maximum temperature produced by the combustion of a unit mass of fuel depends upon

  1. L.C.V.

  2. Ash content

  3. Mass of air supplied

  4. Pressure in the furnace

  Of these statements
  A)
  1 alone is correct done clear
  B)
  1 and 3 are correct done clear
  C)
  2 and 4 are correct          done clear
  D)
  3 and 4 are correct done clear
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• question_answer19)
  The critical pressure ratio \[\left( \frac{{{p}_{2}}}{{{p}_{1}}} \right)\] for maximum discharge through a nozzle is:
  A)
  \[{{\left( \frac{2}{n+1} \right)}^{\left( \frac{n\,\,-\,\,1}{n} \right)}}\]                    done clear
  B)
  \[{{\left( \frac{2}{n+1} \right)}^{\left( \frac{n}{n\,\,-\,\,1} \right)}}\] done clear
  C)
  \[{{\left( \frac{2}{n-1} \right)}^{\left( \frac{n}{n\,\,+\,\,1} \right)}}\]                     done clear
  D)
  \[{{\left( \frac{2}{n-1} \right)}^{\left( \frac{n\,\,+\,\,1}{n} \right)}}\] done clear
  View Solution play_arrow

• question_answer20)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I (Parameter)		List-II (Property)
  A.	Volume	1.	Path function
  B.	Density	2.	Intensive property
  C.	Pressure	3.	Extensive property
  D.	Work	4.	Point function

  Codes:
  A)
  A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1 done clear
  B)
  A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4 done clear
  C)
  A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1 done clear
  D)
  A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4 done clear
  View Solution play_arrow

• question_answer21)
  Ratio of specific heats for an ideal gas is given by:         (Symbols have the usual meanings)
  A)
  \[\frac{1}{1-\frac{R}{{{c}_{p}}}}\]                    done clear
  B)
  \[\frac{1}{1-\frac{{{c}_{p}}}{R}}\] done clear
  C)
  \[\frac{1}{1+\frac{{{c}_{p}}}{R}}\]                  done clear
  D)
  \[\frac{1}{1+\frac{R}{{{c}_{p}}}}\] done clear
  View Solution play_arrow

• question_answer22)
  For a Carnot engine \[{{T}_{1}}>{{T}_{2}}.\] When \[{{T}_{2}}\] is decreased by \[\Delta T\] with \[{{T}_{1}}\] remaining same then efficiency is \[{{\eta }_{1}},\] and when \[{{T}_{1}}\] is increased by \[\Delta T\] with \[{{T}_{2}}\] remaining same, efficiency is \[{{\eta }_{2}}.\] Which one of the following is the correct expression for \[\left( {{\eta }_{1}}-{{\eta }_{2}} \right)?\]
  A)
  \[\frac{({{T}_{2}}-{{T}_{1}})\,\,\Delta \,T+{{(\Delta \,T)}^{2}}}{{{T}_{2}}({{T}_{2}}+\Delta \,T)}\] done clear
  B)
  \[\frac{({{T}_{2}}-{{T}_{1}})\,\,\Delta \,T+{{(\Delta \,T)}^{2}}}{{{T}_{1}}({{T}_{1}}+\Delta \,T)}\] done clear
  C)
  \[\frac{({{T}_{1}}-{{T}_{2}})\,\,\Delta \,T+{{(\Delta \,T)}^{2}}}{{{T}_{1}}({{T}_{1}}+\Delta \,T)}\] done clear
  D)
  \[\frac{({{T}_{1}}-{{T}_{2}})\,\,\Delta \,T+{{(\Delta T)}^{2}}}{{{T}_{1}}({{T}_{1}}+\Delta T)}\] done clear
  View Solution play_arrow

• question_answer23)
  The heat transferred in a thermodynamic cycle of a system consisting of four processes are successively 0, 8, 6 and \[-\,\,4\] units. The net change in the internal energy of the system will be:
  A)
  \[-\,\,8\]                         done clear
  B)
  zero done clear
  C)
  10                                 done clear
  D)
  \[-\,\,10\] done clear
  View Solution play_arrow

• question_answer24)
  If a system undergoes an irreversible adiabatic process, then (symbols have usual meanings:
  A)
  \[\int{\frac{dQ}{T}}\,\,=\,\,0\] and \[\Delta \,S>0\] done clear
  B)
  \[\int{\frac{dQ}{T}\,\,=\,\,0}\] and \[\Delta \,S\,\,=\,\,0\] done clear
  C)
  \[\int{\frac{dQ}{T}>0}\] and \[\Delta \,S\,\,=\,\,0\] done clear
  D)
  \[\int{\frac{dQ}{T}<0}\] and \[\Delta \,S<0\] done clear
  View Solution play_arrow

• question_answer25)
  During a process with heat and work interactions, the internal energy of a system increases by 30 kJ. The amounts of heat and work interactions are respectively:
  A)
  \[-\,\,50\]kJ and \[-\,\,80\]kJ          done clear
  B)
  \[-\,\,50\]kJ and 80 kJ done clear
  C)
  50 kJ and 80 kJ done clear
  D)
  50 kJ and \[-\,\,80\]kJ done clear
  View Solution play_arrow

• question_answer26)
  The mathematical conditions at the critical point for a pure substance would be:
  A)
  \[\frac{\partial p}{\partial v}<0\,;\,\,\frac{{{\partial }^{2}}p}{\partial {{v}^{2}}}=0\] and \[\frac{{{\partial }^{3}}p}{\partial {{v}^{3}}}=0\] done clear
  B)
  \[\frac{\partial p}{\partial v}=0\,;\,\,\frac{{{\partial }^{2}}p}{\partial {{v}^{2}}}<0\] and \[\frac{{{\partial }^{3}}p}{\partial {{v}^{3}}}=0\] done clear
  C)
  \[\frac{\partial p}{\partial v}=0\,;\,\,\frac{{{\partial }^{2}}p}{\partial {{v}^{2}}}=0\] and \[\frac{{{\partial }^{3}}p}{\partial {{v}^{3}}}<0\] done clear
  D)
  \[\frac{\partial p}{\partial v}=0\,;\,\,\frac{{{\partial }^{2}}p}{\partial {{v}^{2}}}=0\] and \[\frac{{{\partial }^{3}}p}{\partial \,{{v}^{3}}}\,\,=\,\,0\] done clear
  View Solution play_arrow

• question_answer27)
  What is the value of slope for an isothermal process on \[p\,-\,v\] diagram for an ideal gas?
  A)
  \[-\,\,p/v\]                       done clear
  B)
  \[-\,\,v/p\] done clear
  C)
  \[-1/(pv)\]                       done clear
  D)
  \[-\,\,pv\] done clear
  View Solution play_arrow

• question_answer28)
  Forced draught fans of a large steam generator have:
  A)
  Backward curved blades done clear
  B)
  Forward curved blades done clear
  C)
  Straight or radial blades done clear
  D)
  Double curved blades done clear
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• question_answer29)
  Air from a reservoir is to be passed through a supersonic nozzle so that the jet will have a Mach Number of 2. If the static temperature of the jet is not to be less than \[27{}^\circ C,\] the minimum temperature of air in the reservoir should be:
  A)
  \[48.6{}^\circ C\]                      done clear
  B)
  \[167{}^\circ C\] done clear
  C)
  \[267{}^\circ C\]                       done clear
  D)
  \[367{}^\circ C\] done clear
  View Solution play_arrow

• question_answer30)
  The air standard efficiency of Diesel cycle will be less than that of Otto cycle in the case of:
  A)
  Same compression ratio and same heat input done clear
  B)
  Same maximum pressure and same heat input done clear
  C)
  Same maximum pressure and same output done clear
  D)
  Same maximum pressure and same maximum temperature done clear
  View Solution play_arrow

• question_answer31)
  A section diverging in the direction of flow can be used as which of the following?

  1. Subsonic nozzle

  2. Supersonic nozzle

  3. Subsonic diffuser

  4. Supersonic diffuser

  Select the correct answer using the code given below:
  A)
  1 only               done clear
  B)
  2 and 3 done clear
  C)
  1 and 4             done clear
  D)
  3 only done clear
  View Solution play_arrow

• question_answer32)
  Air is compressed adiabatically in a steady flow process with negligible change in potential and kinetic energy. The work done in the process is given by:
  A)
  \[-\,\int{p\,\,dv}\]                        done clear
  B)
  \[+\,\int{p\,\,dv}\] done clear
  C)
  \[-\,\int{v\,\,dp}\]                        done clear
  D)
  \[+\,\int{v\,\,dp}\] done clear
  View Solution play_arrow

• question_answer33)
  Which one of the following properties remains unchanged for a real gas during Joule-Thomson process?
  A)
  Temperature                   done clear
  B)
  Enthalpy done clear
  C)
  Entropy             done clear
  D)
  Pressure         done clear
  View Solution play_arrow

• question_answer34)
                               In respect of a closed system, when an ideal gas undergoes a reversible isothermal process:
  A)
  Heat transfer is zero done clear
  B)
  Change in internal energy is equal to work transfer done clear
  C)
  Work transfer is zero done clear
  D)
  Heat transfer is equal to work transfer. done clear
  View Solution play_arrow

• question_answer35)
  The volumetric air content of a tyre at \[27{}^\circ C\] and at 2 bar is 30 litres. If one morning the temperature dips \[-\,\,3{}^\circ C,\] then the air pressure in the tyre would be:
  A)
  1.8 bar done clear
  B)
  11 bar done clear
  C)
  0.8 bar  done clear
  D)
  The same as at \[27{}^\circ C\] done clear
  View Solution play_arrow

• question_answer36)
  One kg of a perfect gas is compressed from pressure \[{{p}_{1}}\] to pressure \[{{p}_{2}}\] by

  1. Isothermal process

  2. Adiabatic process

  3. The law \[p{{v}^{1.1}}\,\,=\,\] constant

  The correct sequence of these processes in increasing order of their work requirement is:
  A)
  1, 2, 3               done clear
  B)
  1, 3, 2 done clear
  C)
  2, 3, 1               done clear
  D)
  3, 1, 2. done clear
  View Solution play_arrow

• question_answer37)
  Triple point temperature of water is:
  A)
  2 73 K               done clear
  B)
  273.14 K done clear
  C)
  273.15 K                       done clear
  D)
  273.16 K. done clear
  View Solution play_arrow

• question_answer38)
  In a test of a water-jacketed compressor, the shaft work required is 90 kN\[\,-\,\]m/kg of air compressed. During compression, increase in enthalpy of air is 30 kJ/kg of air and increase in enthalpy of circulating cooling water is 40 kJ/kg of air. The change in velocity is negligible. The amount of heat lost to the atmosphere from the compressor per kg of air is:
  A)
  20 kJ                 done clear
  B)
  60 kJ done clear
  C)
  80 kJ                 done clear
  D)
  120 kJ done clear
  View Solution play_arrow

• question_answer39)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	The entropy of a pure crystalline substance is zero at absolute zero temperature	1.	First law of thermodynamics
  B.	Spontaneous processes occur in a certain direction	2.	Second law of thermodynamics
  C.	If two bodies are in thermal equilibrium with a third body, then they are also in thermal equilibrium with each other	3.	Third law of thermodynamics
  D.	The law of conservation of energy	4.	Zeroth law of thermodynamics

  Codes:
  A)
  A\[\to \]2, B\[\to \]3, C\[\to \]4, D\[\to \]1 done clear
  B)
  A\[\to \]3, B\[\to \]2, C\[\to \]1, D\[\to \]4 done clear
  C)
  A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1 done clear
  D)
  A\[\to \]2, B\[\to \]3, C\[\to \]1, D\[\to \]4 done clear
  View Solution play_arrow

• question_answer40)
  1600 kJ of energy is transferred from a heat reservoir at 800 K. to another heat reservoir at 400 K. The amount of entropy generated during the process would be:
  A)
  6 kJ/K               done clear
  B)
  4 kJ/K done clear
  C)
  2 kJ/K               done clear
  D)
  zero. done clear
  View Solution play_arrow

• question_answer41)
  For a compression or heating process, what is the expression for effectiveness\[\varepsilon \]?
  A)
  \[\varepsilon \,\,=\,\,\frac{Increase\,\,of\,\,availability\,\,of\,\,the\,\,surroundings}{Loss\,\,of\,\,availability\,\,of\,\,the\,\,system}\] done clear
  B)
  \[\varepsilon \,\,=\,\,\frac{Increase\,\,of\,\,availability\,\,of\,\,the\,\,system}{Loss\,\,of\,\,availability\,\,of\,\,the\,\,surroundings}\] done clear
  C)
   \[\varepsilon \,\,=\,\,\frac{Loss\,\,of\,\,availability\,\,of\,\,the\,\,surroundings}{Increase\,\,of\,\,availability\,\,of\,\,the\,\,system}\] done clear
  D)
  \[\varepsilon \,\,=\,\,\frac{Loss\,\,of\,\,availability\,\,of\,\,the\,\,system}{Increase\,\,of\,\,availability\,\,of\,\,the\,\,surroundings}\] done clear
  View Solution play_arrow

• question_answer42)
  Match List-I (Cycle) with List-II (Process) and select the correct answer using the codes given below the lists:

  List-I (Cycle)		List-II (Process)
  A.	Otto	1.	Two isothermal and two constant volume
  B.	Stirling	2.	Two isothermal and two isobar
  C.	Ericsson	3.	Two isentropic and two isobar
  D.	Brayton	4.	Two isentropic and two constant volume
  		5.	Two isentropic and two isothermal

  Codes:
  A)
  A\[\to \]4, B\[\to \]1, C\[\to \]2, D\[\to \]3 done clear
  B)
  A\[\to \]4, B\[\to \]1, C\[\to \]3, D\[\to \]5 done clear
  C)
  A\[\to \]1, B\[\to \]4, C\[\to \]2, D\[\to \]5 done clear
  D)
  A\[\to \]1, B\[\to \]4, C\[\to \]5, D\[\to \]3 done clear
  View Solution play_arrow

• question_answer43)
  The specific heat \[{{c}_{p}}\] is given by:
  A)
  \[T{{\left( \frac{\partial \,v}{\partial \,T} \right)}_{p}}\]                 done clear
  B)
  \[T{{\left( \frac{\partial \,v}{\partial \,S} \right)}_{p}}\] done clear
  C)
  \[T{{\left( \frac{\partial \,S}{\partial \,T} \right)}_{p}}\]                 done clear
  D)
  \[T{{\left( \frac{\partial \,T}{\partial \,v} \right)}_{p}}\] done clear
  View Solution play_arrow

• question_answer44)
  In free expansion of a gas between two equilibrium states, the work transfer involved:
  A)
  Can be calculated by joining the two states on\[p-v\]Coordinates by any path and estimating the area below done clear
  B)
  Can be calculated by joining the two states by quasi-static path and then finding the area below done clear
  C)
  Is zero done clear
  D)
  Is equal to heat generated by friction during? Expansion done clear
  View Solution play_arrow

• question_answer45)
  Consider the following statements:

  (1) The Second Law analysis can be applied to thermodynamic cycles only and not to individual processes.

  (2) The Second Law analysis clearly gives an idea about the irreversibilities in the heat exchangers whereas no idea is obtained from the First Law analysis.

  Which of the statements given above is/are correct?
  A)
  1 only               done clear
  B)
  2 only done clear
  C)
  Both 1 and 2                  done clear
  D)
  neither 1 nor 2 done clear
  View Solution play_arrow

• question_answer46)
  Which of the following statements are associated with second law of thermodynamics

  1. When a system executes a cyclic process, network transfer is equal to net heat transfer.

  2. It is impossible to construct an engine, that operating in a cycle will produce no other effect than the extraction of heat from a reservoir and performance of an equivalent amount of work.

  3. It is impossible by any procedure, no matter how idealized, to reduce any system the absolute zero of temperature in a finite number of operations

  4. It is impossible to construct a device that operating in a cycle will produce no effect other than transfer of heat from a cooler to hotter body.

  Select the correct answer using the codes given below:
  A)
  1, 2 and 4                      done clear
  B)
  2 and 4 done clear
  C)
  2, 3 and 4                      done clear
  D)
  2 and 3 done clear
  View Solution play_arrow

• question_answer47)
  Clausius inequality is stated as:
  A)
  \[\oint{\delta Q<0}\]                   done clear
  B)
  \[\oint{\delta Q\,\,=\,\,0}\] done clear
  C)
  \[\oint{\frac{\delta Q}{T}>0}\]               done clear
  D)
  \[\oint{\frac{\delta Q}{T}\le 0}\] done clear
  View Solution play_arrow

• question_answer48)
  A heat engine working on Carnot cycle receives heat at the rate of 40 kW from a source at 1200 K and rejects it to a sink at 300 K. The heat rejected is:
  A)
  30 kW               done clear
  B)
  20 kW done clear
  C)
  10 kW               done clear
  D)
  5 kW done clear
  View Solution play_arrow

• question_answer49)
  An electric power generating station produces 400 MW. If the coal releases \[36\,\times \,{{10}^{8}}\] kJ/h of energy, the rate of rejection of heat from the power plant is:
  A)
  200 MW                        done clear
  B)
  400 MW done clear
  C)
  600 MW                        done clear
  D)
  800 MW done clear
  View Solution play_arrow

• question_answer50)
  An ideal gas with initial volume, pressure and temperature of \[0.1\,\,{{m}^{3}},\] 1 bar and \[27{}^\circ C\] respectively is compressed in a cylinder by a piston such that its final volume and pressure are \[0.04\,\,{{m}^{3}}\] and 5 bar respectively, then its final temperature will be:
  A)
  \[-\,\,123{}^\circ C\]                  done clear
  B)
  \[54{}^\circ C\] done clear
  C)
  \[327{}^\circ C\]                       done clear
  D)
  \[600{}^\circ C\] done clear
  View Solution play_arrow

• question_answer51)
  A cyclic heat engine receives 600 kJ of heat from a 1000 K source and rejects 450 kJ to a 300 K sink. The quantity \[\oint{\frac{\delta Q}{T}}\] and efficiency of the engine are respectively:
  A)
  2.1 kJ/K and 70%   done clear
  B)
  \[-\,\,0.9\] kJ/K and 25% done clear
  C)
  \[+\,\,0.9\] kJ/K and 70% done clear
  D)
  \[-\,\,2.1\] kJ/K and 50% done clear
  View Solution play_arrow

• question_answer52)
  Which of the following symptoms show that the combustion in air is necessarily complete:
  A)
  Absence of oxygen in exhaust done clear
  B)
  Absence of nitrogen in exhaust done clear
  C)
  Absence of free carbon in exhaust done clear
  D)
  Absence of carbon monoxide in exhaust done clear
  View Solution play_arrow

• question_answer53)
  Orsat gas analyzer determines volumetric composition of the flue gases in respect of:
  A)
  \[{{O}_{2}}\] and \[{{N}_{2}}\] done clear
  B)
  \[{{O}_{2}}\] and \[C{{O}_{2}}\] done clear
  C)
  \[C{{O}_{2}}\] CO and \[{{N}_{2}}\] done clear
  D)
  \[{{N}_{2}},\] \[{{O}_{2}},\] \[C{{O}_{2}}\] and CO done clear
  View Solution play_arrow

• question_answer54)
  In isentropic flow between two points:
  A)
  The stagnation pressure decreases in the direction of flow done clear
  B)
  The stagnation temperature and stagnation pressure decrease with increase in the velocity done clear
  C)
  The stagnation temperature and stagnation pressure may vary done clear
  D)
  The stagnation temperature and stagnation pressure remain constant done clear
  View Solution play_arrow

• question_answer55)
  Work done in a free expansion process is:
  A)
  Positive             done clear
  B)
  negative done clear
  C)
  Zero                              done clear
  D)
  maximum done clear
  View Solution play_arrow

• question_answer56)
  Match List-I (Quantity) with List-II (Measuring Device) and select the correct answer using the codes given below the lists:

  List-I (Quantity)		List-II (Measuring Device)
  A.	Engine speed	1.	Manometer
  B.	Fuel heating value	2.	Tachometer
  C.	Air velocity	3.	Hydrometer
  D.	Relative humidity of air	4.	Calorimeter
  		5.	Hygrometer

  Codes:
  A)
  A\[\to \]2, B\[\to \]5, C\[\to \]1, D\[\to \]4 done clear
  B)
  A\[\to \]1, B\[\to \]5, C\[\to \]3, D\[\to \]4 done clear
  C)
  A\[\to \]2, B\[\to \]4, C\[\to \]1, D\[\to \]5 done clear
  D)
  A\[\to \]1, B\[\to \]4, C\[\to \]3, D\[\to \]5 done clear
  View Solution play_arrow

• question_answer57)
  For the expression \[\int{p\,\,dv}\] to represent the work, which of the following conditions should apply?
  A)
  The system is closed one and process takes place in non-flow system. done clear
  B)
  The process is non-quasi-static. done clear
  C)
  The boundary of the system should not move in order that work may be transferred. done clear
  D)
  If the system is open one, it should be non- reversible done clear
  View Solution play_arrow

• question_answer58)
  Variation of pressure and volume at constant temperature are correlated through:
  A)
  Charles' law                    done clear
  B)
  Boyle's law done clear
  C)
  Joule's law                     done clear
  D)
  Gay Lussac's law done clear
  View Solution play_arrow

• question_answer59)
  The velocity of sound in an ideal gas does not depend on:
  A)
  The specific heat ratio of the gas done clear
  B)
  The molecular weight of the gas done clear
  C)
  The temperature of the gas done clear
  D)
  The density of the gas done clear
  View Solution play_arrow

• question_answer60)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Joule-Thomson coefficient	1.	5/2 R
  B.	\[{{c}_{p}}\] for monoatomic gas	2.	\[{{c}_{v}}\]
  C.	\[{{c}_{p}}-{{c}_{v}}\] for diatomic gas	3.	R
  D.	\[{{\left( \frac{\partial U}{\partial T} \right)}_{v}}\]	4.	\[{{\left( \frac{\partial T}{\partial p} \right)}_{h}}\]

  Codes:
  A)
  A\[\to \]3, B\[\to \]2, C\[\to \]4, D\[\to \]1 done clear
  B)
  A\[\to \]4, B\[\to \]1, C\[\to \]3, D\[\to \]2 done clear
  C)
  A\[\to \]3, B\[\to \]1, C\[\to \]4, D\[\to \]2 done clear
  D)
  A\[\to \]4, B\[\to \]2, C\[\to \]3, D\[\to \]1 done clear
  View Solution play_arrow

• question_answer61)
  An inventor claims that heat engine has the following specifications:

  Power developed = 50 kW,

  Fuel burned per hour = 3 kg

  Heating value of fuel = 75,000 kJ per kg

  Temperature limits = \[627{}^\circ C\] and \[27{}^\circ C\]

  Cost of fuel =Rs. 30/kg.

  Value of power = Rs. 5/kWh,

  The performance of his engine is:
  A)
  Possible             done clear
  B)
  not possible done clear
  C)
  Economical                    done clear
  D)
  uneconomical done clear
  View Solution play_arrow

• question_answer62)
  In a normal shock wave in one-dimensional flow:
  A)
  Pressure, density and temperature increase done clear
  B)
  Velocity, temperature and density increase done clear
  C)
  Pressure, density and temperature decrease done clear
  D)
  Velocity, pressure and density decrease done clear
  View Solution play_arrow

• question_answer63)
  Identify the process of change of a closed system in which the work transfer is maximum:
  A)
  Isothermal                      done clear
  B)
  Isochoric done clear
  C)
  Isentropic                       done clear
  D)
  Polytropic done clear
  View Solution play_arrow

• question_answer64)
  A system executes a cycle there are four heat transfers:

  \[{{Q}_{12}}\,\,=\,220\,kJ,\]  \[{{Q}_{23}}=-\,25\,\,kJ,\] \[{{Q}_{34}}=-\,180\,\,kJ,\] \[{{Q}_{41}}\,\,=\,\,50\,\,kJ.\]

  The work during three of the processes is:

  \[{{W}_{12}}=15\,\,kJ,\] \[{{W}_{23}}=-\,10\,\,kJ,\] \[{{W}_{34}}=60\,\,kJ.\]The work during the process \[4-1\] is:
  A)
  \[-\,\,230\,kJ\]                 done clear
  B)
  0 kJ done clear
  C)
  230 kJ               done clear
  D)
  130 kJ done clear
  View Solution play_arrow

• question_answer65)
  Which one of the following statements is not correct?
  A)
  Change in entropy during a reversible adiabatic process is zero. done clear
  B)
  Entropy increases with the addition of heat. done clear
  C)
  Throttling is a constant entropy expansion process. done clear
  D)
  Change in entropy when a gas is heated under constant pressure is given by\[{{s}_{2}}-{{s}_{1}}=m{{c}_{p}}\,\,lo{{g}_{e}}\,\frac{{{T}_{2}}}{{{T}_{1}}}\] done clear
  View Solution play_arrow

• question_answer66)
  If u, t, v, s, h and p refer to internal energy, temperature, volume, entropy, enthalpy and pressure respectively; and subscript 0 refers to environment conditions, availability function for a closed system is given by:
  A)
  \[u+{{p}_{0}}v-{{T}_{0}}s\]    done clear
  B)
  \[u-{{p}_{0}}v+{{T}_{0}}s\] done clear
  C)
  \[h+{{p}_{0}}v+{{T}_{0}}s\] done clear
  D)
  \[h-{{p}_{0}}v+{{T}_{0}}s\] done clear
  View Solution play_arrow

• question_answer67)
  If h, p, T and v refer to enthalpy, pressure, temperature and specific volume respectively; and subscripts g and \[f\] refer to saturation conditions of vapour and liquid respectively, then Clausius-Clapeyron equation applied to change of phase from liquid to vapour states is:
  A)
  \[\frac{dp}{dt}=\frac{({{h}_{g}}-{{h}_{f}})}{({{v}_{g}}-{{v}_{f}})}\] done clear
  B)
  \[\frac{dp}{dt}=\frac{({{h}_{g}}-{{h}_{f}})}{T\,({{v}_{g}}-{{v}_{f}})}\] done clear
  C)
  \[\frac{dp}{dt}=\frac{({{h}_{g}}-{{h}_{f}})}{T}\]         done clear
  D)
  \[\frac{dp}{dt}=\frac{({{v}_{g}}-{{v}_{f}})T}{({{h}_{g}}-{{h}_{f}})}\] done clear
  View Solution play_arrow

• question_answer68)
  A gas turbine cycle with infinitely large number of stages during compression and expansion approaches:
  A)
  Stirling cycle                   done clear
  B)
  Atkinson cycle done clear
  C)
  Ericsson cycle                 done clear
  D)
  Brayton cycle done clear
  View Solution play_arrow

• question_answer69)
  The COP of a refrigerator on a reversed Carnot cycle is 5. The ratio of higher absolute temperature to the lower temperature \[(i.e.,\,\,{{T}_{2}}/{{T}_{1}})\] is:
  A)
  1.25                              done clear
  B)
  1.3 done clear
  C)
  1.4                                done clear
  D)
  1.2 done clear
  View Solution play_arrow

• question_answer70)
  For an ideal gas, the expression \[\left[ T\,{{\left( \frac{\partial s}{\partial T} \right)}_{p}}-T\,{{\left( \frac{\partial s}{\partial T} \right)}_{v}} \right]\] is equal to:
  A)
  Zero                              done clear
  B)
  \[{{c}_{p}}/{{c}_{v}}\] done clear
  C)
  R                                  done clear
  D)
  RT done clear
  View Solution play_arrow

• question_answer71)
  or a non-flow constant pressure process, the heat exchange is equal to:
  A)
  Zero done clear
  B)
  The work done done clear
  C)
  The change in internal energy done clear
  D)
  The change in enthalpy done clear
  View Solution play_arrow

• question_answer72)
  For a real thermodynamic cycle:
  A)
  \[\oint{\frac{dQ}{T}}>but<\infty \]         done clear
  B)
  \[\oint{\frac{dQ}{T}}<0\] done clear
  C)
  \[\oint{\frac{dQ}{T}}=0\]          done clear
  D)
  \[\oint{\frac{dQ}{T}}=\infty \] done clear
  View Solution play_arrow

• question_answer73)
  A higher value of Van der Waals constant for a gas indicates that the:
  A)
  Molecules of the gas have smaller diameter done clear
  B)
  Gas can be easily liquified done clear
  C)
  Gas has higher molecular weight done clear
  D)
  Gas has lower molecular weight done clear
  View Solution play_arrow

• question_answer74)
  Total enthalpy of steam at the inlet of a nozzle is 2800 kJ while static enthalpy at the exit is 2555 kJ. What is the steam velocity at the exit if expansion is isentropic?
  A)
  70 m/s               done clear
  B)
  245 m/s done clear
  C)
  450 m/s             done clear
  D)
  700 m/s done clear
  View Solution play_arrow

• question_answer75)
  In an adiabatic process 6000 J of work is performed on a system. In the non-adiabatic process by which the system returns to its original state, 1000 J of heat is added to the system. What is the work done during non-adiabatic process?
  A)
  \[+\,\,7000\,\,J\]             done clear
  B)
  \[-\,\,7000\,\,J\] done clear
  C)
  \[+\,\,5000\,\,J\]             done clear
  D)
  \[-\,\,5000\,\,J\] done clear
  View Solution play_arrow

• question_answer76)
  Heat flows between two reservoirs having temperatures 1000 K and 500 K, respectively. If the entropy change of the cold reservoir is 10 kJ/K, then what is the entropy change for the hot reservoir?
  A)
  \[-\,\,10\,\,kJ/K\]              done clear
  B)
  \[-\,\,5\,\,kJ/K\] done clear
  C)
  \[5\,\,kJ/K\]                    done clear
  D)
  \[10\,\,kJ/K\] done clear
  View Solution play_arrow

• question_answer77)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Bottle filling of gas	1.	Absolute zero temperature
  B.	Nernst-Simon statement	2.	Variable flow
  C.	Joule-Thomson effect	3.	Quasi-static path
  D.	\[\int{p\,\,dv}\]	4.	Isenthalpic process
  		5.	Dissipative effect
  		6.	Low grade energy
  		7.	Pressure and temperature during phase change

  Codes:
  A)
  A\[\to \]6, B\[\to \]5, C\[\to \]4, D\[\to \]3 done clear
  B)
  A\[\to \]2, B\[\to \]1, C\[\to \]4, D\[\to \]3 done clear
  C)
  A\[\to \]2, B\[\to \]5, C\[\to \]7, D\[\to \]4 done clear
  D)
  A\[\to \]6, B\[\to \]1, C\[\to \]7, D\[\to \]4 done clear
  View Solution play_arrow

• question_answer78)
  \[{{M}_{1}}\] kg of water at \[{{T}_{1}}\] is isobarically and adiabatically mixed with \[{{M}_{2}}\,\,kg\] of water at \[{{T}_{2}}\,({{T}_{1}}>{{T}_{2}}).\] The entropy change of the universe is:
  A)
  Necessarily positive done clear
  B)
  Necessarily negative done clear
  C)
  Always zero done clear
  D)
  Negative or positive but not zero done clear
  View Solution play_arrow

• question_answer79)
  A heat engine using lake water at \[12{}^\circ C\] as source and the surrounding atmosphere at \[2{}^\circ C\] as sink executes 1080 cycles per minute. If amount of heat supplied per cycle is 57 J, what is the output of the engine?
  A)
  66 W                 done clear
  B)
  56 W done clear
  C)
  46 W                 done clear
  D)
  36 W      done clear
  View Solution play_arrow

• question_answer80)
           A reversible heat engine runs between high temperature \[{{T}_{1}}\] and low temperature \[{{T}_{2}}.\] the work output of this heat engine is used to run a reversible refrigeration cycle absorbing heat at temperature \[{{T}_{3}}\] and rejecting at temperature \[{{T}_{2}}.\]what is the COP of the combined system?
  A)
  \[\left( \frac{{{T}_{1}}-{{T}_{2}}}{{{T}_{1}}} \right)\,\,\left( \frac{{{T}_{3}}}{{{T}_{2}}-{{T}_{3}}} \right)\] done clear
  B)
  \[\left( \frac{{{T}_{2}}}{{{T}_{1}}-{{T}_{2}}} \right)\,\,\left( \frac{{{T}_{2}}-{{T}_{3}}}{{{T}_{3}}} \right)\] done clear
  C)
  \[\left( \frac{{{T}_{1}}}{{{T}_{1}}-{{T}_{2}}} \right)\,\,\left( \frac{{{T}_{3}}}{{{T}_{2}}-{{T}_{3}}} \right)\] done clear
  D)
  \[\left( \frac{{{T}_{3}}}{{{T}_{1}}-{{T}_{3}}} \right)\,\,\left( \frac{{{T}_{1}}}{{{T}_{2}}-{{T}_{1}}} \right)\] done clear
  View Solution play_arrow

• question_answer81)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Reversible cycle	1.	Measurement of temperature
  B.	Mechanical work	2.	Clapeyron equation
  C.	Zeroth Law	3.	Clausius Theorem
  D.	Heat	4.	High grade energy
  		5.	\[{{3}^{rd}}\] Law of thermodynamics
  		6.	In exact differential

  Codes:
  A)
  A\[\to \]3, B\[\to \]4, C\[\to \]1, D\[\to \]6 done clear
  B)
  A\[\to \]2, B\[\to \]6, C\[\to \]1, D\[\to \]3 done clear
  C)
  A\[\to \]3, B\[\to \]1, C\[\to \]5, D\[\to \]6 done clear
  D)
  A\[\to \]1, B\[\to \]4, C\[\to \]5, D\[\to \]2 done clear
  View Solution play_arrow

• question_answer82)
  A. closed thermodynamic system is one in which:
  A)
  There is no energy or mass transfer across the boundary done clear
  B)
  There is no mass transfer, but energy transfer exists done clear
  C)
  There is no energy transfer. But mass transfer exists done clear
  D)
  Both energy and mass transfer take place across the boundary, but the mass transfer is controlled by valves done clear
  View Solution play_arrow

• question_answer83)
  A refrigerating machine working on reversed Carnot cycle takes out 2 kW of heal from the system at 200 K while working between temperature limits of 300 K and 200 K. COP and power consumed by the cycle will respectively, be:                           
  A)
  1 and 1 kW                    done clear
  B)
  1 and 2 kW          done clear
  C)
  2 and 1 kW                    done clear
  D)
  2 and 2 kW     done clear
  View Solution play_arrow

• question_answer84)
       If a gas obeys Van-der Waals equation at the critical point, then what does \[\frac{R{{T}_{c}}}{{{P}_{c}}{{V}_{c}}}\] equal to?
  A)
  Zero                              done clear
  B)
  unity               done clear
  C)
  1.50                              done clear
  D)
  2.67    done clear
  View Solution play_arrow

• question_answer85)
           For a gas, pressure p, volume v and temperature T are dependent on each other. Then which one of the following \[p\,-\,v\,-T\] relationships will be obeyed? 
  A)
  \[{{\left( \frac{\partial p}{\partial T} \right)}_{v}}\,{{\left( \frac{\partial v}{\partial T} \right)}_{p}}\,{{\left( \frac{\partial v}{\partial p} \right)}_{T}}\,=-\,\,1\] done clear
  B)
  \[{{\left( \frac{\partial p}{\partial T} \right)}_{v}}\,{{\left( \frac{\partial T}{\partial v} \right)}_{p}}\,{{\left( \frac{\partial v}{\partial p} \right)}_{T}}=-\,\,1\] done clear
  C)
  \[{{\left( \frac{\partial p}{\partial T} \right)}_{v}}\,{{\left( \frac{\partial v}{\partial T} \right)}_{p}}\,{{\left( \frac{\partial p}{\partial v} \right)}_{T}}=-\,\,1\] done clear
  D)
  \[{{\left( \frac{\partial p}{\partial T} \right)}_{v}}={{\left( \frac{\partial T}{\partial v} \right)}_{p}}\,{{\left( \frac{\partial p}{\partial v} \right)}_{T}}\] done clear
  View Solution play_arrow

• question_answer86)
  A battery is used to light a bulb, run a fan and heat an electric iron in case of a power failure. If each of the above systems has 100 W rating and is run for 15 minutes, what are the work done (W) and heat transferred (Q) by the battery'?
  A)
  W = 90 kJ and Q = 90 kJ done clear
  B)
  W = 180 kJ and Q = 0 done clear
  C)
  W = 270 kJ and Q = 0 done clear
  D)
  W = 90 kJ and Q = 180 kJ done clear
  View Solution play_arrow

• question_answer87)
  Match List-I with List-II and select the correct answer using the codes given below the lists:

  List-I		List-II
  A.	Heat	1.	PMM-2
  B.	Engine	2.	High grade energy
  C.	Stirring work	3.	Variable flow
  D.	Mechanical work	4.	Nernst-Simon statement
  		5.	Dissipative
  		6.	Inexact differential
  		7.	PMM-1

  Codes:
  A)
  A\[\to \]2, B\[\to \]5, C\[\to \]4, D\[\to \]3 done clear
  B)
  A\[\to \]2, B\[\to \]1, C\[\to \]5, D\[\to \]7 done clear
  C)
  A\[\to \]6, B\[\to \]5, C\[\to \]4, D\[\to \]2 done clear
  D)
  A\[\to \]6, B\[\to \]1, C\[\to \]5, D\[\to \]2 done clear
  View Solution play_arrow

• question_answer88)
  A system undergoes a change of state during which 100 kJ of heat is transferred to it and it does 50 kJ of work. The system is brought back to its original state through a process during which 120 kJ of heat is transferred to it. What is the work done by the system?
  A)
  50 kJ                 done clear
  B)
  70 kJ done clear
  C)
  120 kJ               done clear
  D)
  170 kJ done clear
  View Solution play_arrow

• question_answer89)
  A reversible engine exchanges heat from three thermal reservoirs A, B and C at 1000 K, 800 K and 200 K respectively. If the engine receives 500 kJ from .A and 400 kJ from B, then what is the heat exchanged from thermal reservoir C?
  A)
  450 kJ rejected to thermal reservoir C done clear
  B)
  350 kJ rejected to thermal reservoir C done clear
  C)
  250 kJ rejected to thermal reservoir C done clear
  D)
  200 kJ rejected to thermal reservoir C done clear
  View Solution play_arrow

• question_answer90)
  A 100Q resistor carrying a constant current of 0.5 A is kept at a constant temperature of 300 K by a stream of cooling water. In a time interval of 30 minutes, what are the changes in entropy for the resistor and that of the universe, respectively?
  A)
  0 and 150 J/K    done clear
  B)
  150 J/K and 0 done clear
  C)
  300 J/K and 0    done clear
  D)
  0 and 300 J/K done clear
  View Solution play_arrow

• question_answer91)
  A system of 100 kg mass undergoes a process in which its specific entropy increase's from 0.30 kJ/kg K to 0.35 kJ/kg K. At the same time, the entropy of the surroundings decreases from 80 kJ/K to 75 kJ/K. What is the type of this process?
  A)
  Reversible done clear
  B)
  Irreversible done clear
  C)
  Impossible done clear
  D)
  Not identifiable with the data given done clear
  View Solution play_arrow

• question_answer92)
  Two reversible engines are working in series between a high temperature reservoir at 1000 K and a low temperature reservoir at 300 K in such a way that the heat rejected by the preceding engine is completely absorbed by the succeeding engine and both the engines develop the same amount of work per cycle. What is the intermediate temperature between first and second engines?
  A)
  700 K done clear
  B)
  650 K done clear
  C)
  350 K done clear
  D)
  Not possible to be estimated with the given data done clear
  View Solution play_arrow

• question_answer93)
  Which one of the following is the correct statement?
  A)
  The Mach number is less than 1 at a point where the entropy is maximum whether it is Rayleigh or Fanno line. done clear
  B)
  A normal shock can appear in subsonic flow. done clear
  C)
  The downstream Mach number across a normal shock is mate than one. done clear
  D)
  The stagnation pressure across a normal shock decreases. done clear
  View Solution play_arrow

• question_answer94)
  What is/are the effect (s) of super saturation in nozzle flow?

  1. It increases the mass flow.

  2. It increases friction in the nozzle.

  3. It increases exit velocity.

  4. It reduces dryness fraction of steam.

  Select the correct answer using the code given below:
  A)
  1 only               done clear
  B)
  1 and 3 done clear
  C)
  1, 2 and 4                      done clear
  D)
  3 only done clear
  View Solution play_arrow

• question_answer95)
  Consider the following statements:

  A tube section diverging in the direction of fluid flow can be used as

  1. Supersonic nozzle

  2. Subsonic nozzle

  3. Supersonic diffuser

  4. Subsonic diffuser

  Which of the statements given above is/are correct?
  A)
  1 only               done clear
  B)
  1 and 4 done clear
  C)
  3 only               done clear
  D)
  2 and 3 done clear
  View Solution play_arrow

• question_answer96)
  Which one of the following is the shock that occurs for an airplane travelling at supersonic speed?
  A)
  Normal shock     done clear
  B)
  Oblique shock done clear
  C)
  Bow shock                     done clear
  D)
  Air shock done clear
  View Solution play_arrow

• question_answer97)
  What does choked flow through a steam nozzle mean?

  1. Discharge is maximum

  2. Discharge is zero

  3. Throat velocity is sonic

  4. Exit pressure is less than or equal to critical pressure

  Select the correct answer using the code given below:
  A)
  1 only               done clear
  B)
  2 only done clear
  C)
  1 and 3 only                  done clear
  D)
  1, 3 and 4 done clear
  View Solution play_arrow

• question_answer98)
  When a convergent-divergent nozzle is subjected to a pressure ratio \[{{{p}_{2}}}/{{{p}_{1}}}\;\] greater than the critical pressure ratio, what does the divergent section exhibit?
  A)
  Decreasing pressure         done clear
  B)
  Flow separation done clear
  C)
  Normal shock     done clear
  D)
  Increasing pressure done clear
  View Solution play_arrow

• question_answer99)
  What are the properties of a thermodynamic system, whose value for the entire system is equal to the sum of their values for individual parts of the system?
  A)
  Thermodynamic properties done clear
  B)
  Extensive properties done clear
  C)
  Intensive properties done clear
  D)
  None of the above done clear
  View Solution play_arrow

• question_answer100)
  A new temperature scale in degrees N is to be defined. The boiling and freezing points of water on this scale are \[400{}^\circ N\] and \[100{}^\circ N\] respectively. What will be the reading on new scale corresponding to \[60{}^\circ C?\]
  A)
  \[110{}^\circ N\]                       done clear
  B)
  \[180{}^\circ N\] done clear
  C)
  \[210{}^\circ N\]                       done clear
  D)
  \[280{}^\circ N\] done clear
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• question_answer101)
  Which of the following thermodynamic properties relate to the Clausius-Clapeyron equation?

  1. Pressure

  2. Temperature

  3. Entropy

  4. Specific volume

  5. Enthalpy

  6. Internal energy

  Select the correct answer using the code given below:
  A)
  1, 2, 6, 5                       done clear
  B)
  4, 2, 3, 5 done clear
  C)
  6, 4, 1               done clear
  D)
  4, 5, 2, 1 done clear
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• question_answer102)
  Which one of the following is heat absorbed or rejected during a polytropic process?
  A)
  \[\left( \frac{\gamma -n}{\gamma -1} \right)\times \] work done done clear
  B)
  \[{{\left( \frac{\gamma -n}{\gamma -1} \right)}^{2}}\times \] work done done clear
  C)
  \[{{\left( \frac{\gamma -n}{\gamma -1} \right)}^{3}}\times \] work done done clear
  D)
  \[\left( \frac{\gamma -n}{1-n} \right)\times \]work done done clear
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• question_answer103)
  During a cycle comprising four processes, the heat transfers during three processes are \[+\,\,45\,\,kJ,\] \[-\,\,30\,\,kJ,\] \[-\,\,25\,\,kJ.\] what should be the heat transfer during the fourth process so that the network done during the cycle is zero?
  A)
  Zero                              done clear
  B)
  \[+\,\,10\,\,kJ\] done clear
  C)
  \[-\,\,10\,\,kJ\]                 done clear
  D)
  \[-\,\,20\,\,kJ\] done clear
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• question_answer104)
  Which thermometer is independent of the substance or material used in its construction?
  A)
  Mercury thermometer done clear
  B)
  Alcohol thermometer done clear
  C)
  Ideal gas thermometer done clear
  D)
  Resistance thermometer done clear
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• question_answer105)
  A closed system undergoes a process during which 150 kJ of heat is added to it. The system is then restored to its initial state. If the heat transfer and work transfer for the second process are \[-\,\,50\,\,kJ\] and \[+\,\,75\,\,kJ\] respectively, what is the work transfer for the first process?
  A)
  25 kJ                 done clear
  B)
  50 kJ done clear
  C)
  75 kJ                 done clear
  D)
  100 kJ done clear
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• question_answer106)
  A heat engine in a thermodynamic cycle draws 500 kJ of heat energy from a source at 1000 K per cycle and rejects certain amount of heat energy at 300 K per cycle. Then, which one of the following is correct?
  A)
  The amount of heat energy rejected must be 150 kJ done clear
  B)
  The amount of heat energy rejected must be less than 150 kJ done clear
  C)
  (e) The amount of heat energy rejected must be greater than 150 kJ done clear
  D)
  It is not possible to make any statement regarding the amount of heat energy rejected per cycle from the data given done clear
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• question_answer107)
  An ideal heat pump and an ideal refrigerator, which are reversible in operation, operate between same upper and lower temperature limits. If the coefficient of performance of the refrigerator is 4.5, then what  is the coefficient of performance of the heat pump
  A)
  3.5                                done clear
  B)
  5.5               done clear
  C)
  2.5                                done clear
  D)
  6.5 done clear
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• question_answer108)
                Air standard diesel cycle has a compression ratio of 14 and cut-off takes place at 6% of the stroke. What is the cut-off ratio?                          
  A)
  0.60                              done clear
  B)
  0.78             done clear
  C)
  1.78                              done clear
  D)
  None of the above done clear
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• question_answer109)
    The thermal efficiency of the Carnot engine is 0.5. If the engine is operated as refrigerator, what is the COP of the refrigerator?                     
  A)
  0.5                                done clear
  B)
  1.0              done clear
  C)
  2.0                                done clear
  D)
  25 done clear
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• question_answer110)
                In a reversible isothermal expansion process, the fluid expands, from 10 bar and \[2\,{{m}^{3}}\] to 2 bar and \[10\,{{m}^{3}}.\] during the process the heat supplied is at the rate of 100 kW. What is the rate of work done during the process?
  A)
  20 kW               done clear
  B)
  35 kW         done clear
  C)
  80 kW               done clear
  D)
  100 kW   done clear
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• question_answer111)
      A system undergoes a change of state during which 80 kJ of heat is transferred to it and it does 60 kJ of work. The system is brought hack to its original slate through a process during which 100 kJ of heat is transferred to it. The work done by the system is:
  A)
  40 kJ                 done clear
  B)
  60 KJ            done clear
  C)
  120 kJ               done clear
  D)
  180 kJ    done clear
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• question_answer112)
        Thermodynamic work is the product of:      
  A)
  Two intensive properties                  done clear
  B)
  Two extensive properties                   done clear
  C)
  An intensive property and change in an extensive property                                  done clear
  D)
  An extensive property and change in an intensive property done clear
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• question_answer113)
  A reversible heat engine operating between hot and cold reservoirs delivers a work output of 54 kJ white it rejects a heat of 66 kJ. The efficiency of this engine
  A)
  0.45                              done clear
  B)
  0.66              done clear
  C)
  0.75                              done clear
  D)
  0.82       done clear
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• question_answer114)
         Which one of the following expressions for Tds is true for a simple compressible substance?             (Notations have the usual meaning)
  A)
  \[dh-vdp\]                      done clear
  B)
  \[dh+vdp\] done clear
  C)
  \[dh-pdv\]                      done clear
  D)
  \[dh+pdv\] done clear
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• question_answer115)
  If a pure substance contained in a rigid vessel passes through the critical state on heating, its initial state should be:                                    
  A)
  Sub cooled water            done clear
  B)
  Saturated water                                           done clear
  C)
  Wet steam                     done clear
  D)
  Saturated steam   done clear
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• question_answer116)
                                                   Which one of the following is the correct expression for change in the internal energy for a small temperature change \[\Delta T\] for an ideal gas?
  A)
  \[\Delta u={{c}_{v}}\times \Delta T\]      done clear
  B)
  \[\Delta u={{c}_{p}}\times \Delta T\] done clear
  C)
  \[\Delta u=\frac{{{c}_{p}}}{{{c}_{v}}}\times \Delta T\] done clear
  D)
  \[\Delta u=\left( {{c}_{p}}-{{c}_{v}} \right)\Delta T\] done clear
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• question_answer117)
  Which of the following are pure substances?

  1.  Steam and water mixture in a container

  2. Atmospheric air

  3. Air and liquid air in a container

  4. Gaseous combustion products

  Select the correct answer using the codes given below:

  Codes:
  A)
  1, 2 and 3 and 4 done clear
  B)
  2, 3 and 4 done clear
  C)
  1, 3 and 4                      done clear
  D)
  1, 2 and 4 done clear
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• question_answer118)
  The entropy of a mixture of pure gases is the sum of The entropies of constituents evaluated at:
  A)
  Temperature and pressure of the mixture done clear
  B)
  Temperature of the mixture and the partial pressure of the constituents done clear
  C)
  Temperature and volume of the mixture done clear
  D)
  Pressure and volume of the mixture done clear
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• question_answer119)
  The Gibbs free-energy function is a property comprising:
  A)
  Pressure, volume and temperature done clear
  B)
  Enthalpy, temperature and entropy done clear
  C)
  Temperature, pressure and enthalpy done clear
  D)
  Volume, enthalpy and entropy done clear
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• question_answer120)
  An electric motor of 5 kW is subjected to a braking test for 1 hour. The heat generated by the frictional forces in the process is transferred to the surroundings \[20{}^\circ C.\] The resulting entropy change will be:
  A)
  22.1 kJ/K                       done clear
  B)
  30.2 kJ/K done clear
  C)
  61.4 kJ/K                       done clear
  D)
  82.1 kJ/K done clear
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