Classification following properties of the system in Intensive and Extensive

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1 Unit I Classification following properties of the system in Intensive and Extensive Extensive : mass, weight, volume, potential energy, Kinetic energy, Internal energy, entropy, exergy, energy, magnetization Intensive : viscosity, specific volume, pressure, Temperature, velocity, density, specific entropy, mole fraction, surface tension, elevation, Thermal conductivity, specific heat, refractive index, electrical conductivity, Type A Question 1. Which of the following is correct? A. Gauge pressure = Absolute pressure- Atmospheric pressure B. Gauge pressure = Absolute pressure + Atmospheric pressure C. Atmospheric pressure = Gauge pressure + Absolute pressure D. Absolute pressure = Gauge pressure - Atmospheric pressure 2. The Work done in a free expansion (Unrestrained expansion) or Throttling process is? A. Zero B. Maximum C. Positive D. Minimum 3. A system does not work even when heat is added to it. Which of the following may happen to the system? A. The system expands B. The internal energy of the system increases C. Both A and B D. Neither A nor B 4. Which of the following is a pure substance? A. Iron B. Gasoline C. Cow s milk D. Sea water 5. Which one of the following expresses the reversible work done by the system (steady flow)? A. pdv B. - vdp C. - pdv D. vdp 6. Consider the following statements: 1. Zeroth law of thermodynamics is related to measurement of temperature 2. Entropy is related to first law of thermodynamics 3. Internal energy of an ideal gas is a function of temperature and pressure Which of the above statements is/are correct? A. 1 only B. 2 and 3 1

2 C. 1 and 3 D. 2 only 7. Match List-I (Parameter) with List-II (Property) and select the correct answer using the codes given below the lists: List-I List-II A. Volume 1. Path function B. Density 2. Intensive property C. Pressure 3. Extensive property D. Work 4. Point function A B C D A B C D Carnot cycle refrigerator operate between 250K and 300K, the COP is? A. 6 B. 5 C. 1.2 D What is the efficiency of a heat engine that operates between reservoirs oftemperatures as 1400 K and 1000K? A. 4% B % C % D. 40% 10. A Refrigerator & Heat pump operate between the same Temperature limits. If COP of the refrigerator is 4, the COP of heat pump would be: A. 3 B. 5 C. 4 D The higher temp limit of a Carnot engine is 773K while its lower temp limit is 400K less than this temperature, the efficiency of the Carnot engine is: A % B % C % D % 12. Consider a refrigerator and a heat pump working on the reversed Carnot cycle between the same temperature limits. which of the following is correct A. COP refrigerator = COP of heat pump B. COP refrigerator = COP of heat pump - 1 C. COP refrigerator = COP of heat pump + 1 2

3 D. COP refrigerator = inverse of COP of heat pump 13. A heat engine operating the source temperature at infinite C and rejecting heat at a ambient condition the efficiency of ideal hypothetical cycle (Carnot cycle ) can be A. less than 50% B. infinite % C. 100% D. must be less than 100% 12. If the thermal efficiency of Carnot engine is 0.20 The COP of a Carnot refrigerator working on same temperature limit A. 5 B. 4 C. 6 D Work done is zero for the following process A. constant volume B. free expansion C. throttling D. all of the above 14. The unit of energy in SI units is. A. Joulemeter B. Joule(Nm) C. Joulemeter D. Watt 15. The first law of thermodynamics for steady flow: A. Accounts for all energy entering and leaving a control volume B. Is an energy balance for a specified mass of fluid C. Is an expression of the conservation of linear momentum D. Is primarily concerned with heat transfer. 16. The absolute zero temperature is taken as? A C B K C. 0 F D K 17. Absolute zero pressure will occur A. at sea level B. when molecular momentum of the system becomes zero C. under vacuum conditions D. at a temperature of K 18. The following are examples of some intensive and extensive properties: 1. Pressure 2. Temperature 3. Volume 4. Velocity 5. Electric charge 6. Magnetisation 7. Viscosity 8. Potential energy. Which one of the following sets gives the correct combination of intensive and extensive properties? 3

4 Intensive Extensive A. 1,2,3,4 5,6,7,8 B. 1,3,5,7 2,4,6,8 C. 1,2,4,7 3,5,6,8 D. 2,3,6,8 1,4,5,7 19. It is the characteristic feature of Quasi-static process system? A. Infinite slowness B. Rapidity C. Stability D. Stationary existence 20. Which of the following are intensive properties? 1. Kinetic Energy 2. Specific Enthalpy 3. Pressure 4. Entropy Select the correct answer using the code given below: A. 1 and 3 B. 2 and 3 C. 1, 3 and 4 D. 2 and 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. Pdv B. + Pdv C. vdp D. + vdp 22. Consider the following properties: 1. Temperature 2. Viscosity 3. Specific entropy 4. Thermal conductivity, Which of the above properties of a system is/are intensive? A. 1 only B. 2 and 3 only C. 2, 3 and 4 only D. 1, 2, 3 and Which one of the following is the extensive property of a thermodynamic system? A. Volume B. Pressure C. Temperature D. Density 24. Consider the following properties: 1. Entropy 2. Viscosity 3. Temperature 4. Specific heat at constant volume 4

5 Which of the above properties of a system is/are extensive? A. 1 only B. 1 and 2 only C. 2, 3 and 4 D. 1, 2 and A closed thermodynamic system is one in which A. There is no energy or mass transfer across the boundary B. There is no mass transfer, but energy transfer exists C. There is no energy transfer, but mass transfer exists D. Both energy and mass transfer take place across the boundary, but the mass transfer is controlled by valves 26. Ice kept in a well-insulated thermo flask is an example of which system? A. Closed system B. Isolated systems C. Open system ` D. Non-flow adiabatic system 27. Measurement of temperature is based on... law of thermodynamics? A. Zeroth law of thermodynamics B. First law of thermodynamics C. Second law of thermodynamics D. Third law of thermodynamics 28. Consider the following statements: 1. Zeroth law of thermodynamics is related to temperature 2. Entropy is related to first law of thermodynamics 3. Internal energy of an ideal gas is a function of temperature and pressure Which of the above statements is/are correct? A. 1 only B. 2 and 3 C. 1 and 3 D. 2 only 29. Zeroth Law of thermodynamics states that A. Two thermodynamic systems are always in thermal equilibrium with each other. B. If two systems are in thermal equilibrium, then the third system will also be in thermal equilibrium with each other. C. Two systems not in thermal equilibrium with a third system are also not in thermal equilibrium with each other. D. When two systems are in thermal equilibrium with a third system, they are in thermal equilibrium with each other. 30. Assertion (A): The change in heat and work cannot be expressed as difference between the end states. 5

6 Reason (R): Heat and work are both exact differentials. A. Both A and R are individually true and R is the correct explanation of A B. Both A and R are individually true but R is NOT the correct explanation of A C. A is true but R is false D. A is false but R is true 31. 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. 3rd law of thermodynamics 6. Inexact differential Codes: A B C D A B C D Match List-I with List-II and select the correct answer: List-I List-II A. The entropy of a pure crystalline is zero at absolute zero temperature 1. 1 st law of thermodynamics B. Spontaneous processes occur in a certain direction 2. 2 nd law of thermodynamics C. If two bodies are in thermal equilibrium with a third body, 3. 3 rd law of thermodynamics then they are also in thermal equilibrium with each other D. The law of conservation of energy 4. 0 th law of thermodynamics. Codes: A B C D A B C D 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 B. Can be calculated by joining the two states by a quasi-static path and then finding the area below 6

7 C. Is zero D. Is equal to heat generated by friction during expansion 34. Thermodynamic work is the product of A. Two intensive properties B. Two extensive properties C. An intensive property and change in an extensive property D. An extensive property and change in an intensive property 35. For the expression pdv 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 B. The process is non-quasi static C. The boundary of the system should not move in order that work may be transferred D. If the system is open one, it should be non-reversible 36. Match items in List-I (Process) with those in List-II (Characteristic) and select the correct answer using the codes given below the lists: List-I List-II A. Throttling process 1. No work done B. Isentropic process 2. No change in entropy C. Free expansion 3. Constant internal energy D. Isothermal process 4. Constant enthalpy Codes: A B C D A B C D The cyclic integral of this is zero A. Work Transfer B. Heat Transfer C. Temperature D. Latent Heat 38. Which of the following statement is true A. Specific volume is extensive property B. Intensive properties are independent on size of system and may vary from place to place within the system at any moment C. Work is extensive property D. Heat is intensive property 7

8 39. The processes occurring in open system which permit the transfer of mass to and from the system, are known as A. Flow processes B. Non-flow processes C. Adiabatic processes D. None of these 40. If Gauge pressure measured inside compressor is 12 bar what is absolute pressure in co compressor kn/m 2? A. 1200kN/m 2 B kN/m 2 C. 1300kN/m 2 D kN/m An adiabatic process is one in which A. No heat enters or leaves the gas B. The temperature of the gas changes C. The change in internal energy is equal to the mechanical work done D. All of these 42. Sum of internal energy (U) and the product of pressure and volume (p.v) is known as by? A. Work done B. Entropy C. Enthalpy D. Exergy 43. The value of 1 mm of Hg is equal to? A N/m 2 B N/m 2 C kn/m 2 D kn/m According to Kelvin-Planck's statement of second law of thermodynamics A. It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work B. It is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work C. It is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body D. None of the above 45. Kelvin Planck's law deals with A. conservation of heat B. conservation of work C. conversion of heat into work 8

9 D. conversion from work into heat E. conservation of mass 46. A Fan is running in insulated room (Heat generation in a room is zero) the temperature of the room A. Will decrease with time B. Will increase with time C. Will constant D. May increase or Decrease 47. A process, in which the temperature of the working substance remains constant, is called A. Isobaric process B. Isothermal Process C. Adiabatic process D. Isenthalpic Process 48. PMM II violates the A. Clausius statement (It is also statement of second law) B. Kelvin- Plank statement C. First law D. Third law 49. Entropy of the universe is A. continuously increasing B. continuously decreasing C. zero D. constant 50. The efficiency of thermodynamic cycle cannot be infinite since it A. Violates the first law of thermodynamics B. Violates the second law of thermodynamics C. Violates the third law of thermodynamics D. Reject no heat 51. Which of the following gives the generalized equation for the First law of thermodynamics A. Q- W = ΔE B. Q- W = KE C. Q- W = Δh D. Q-W = ΔU 52. Which of the following is related to Zeroth law of thermodynamics... A. Introduces the concept of Internal Energy B. Provide basis for measurement of temperature C. Introduces the concept of Entropy, Exergy and Kelvin temperature scale D. Absolute zero pressure 9

10 53. Which of the following is related to First law of thermodynamics... A. Introduces the concept of Internal Energy B. Provide measurement of temperature C. Introduces the concept of Entropy, Exergy and Kelvin temperature scale D. Absolute zero pressure 54. Which of the following is related to Second law of thermodynamics... A. Introduces the concept of Internal Energy B. Provide measurement of temperature C. Introduces the concept of Entropy, Exergy D. Absolute zero temperature 55. Which of the following is related to Third law of thermodynamics... A. Introduces the concept of Internal Energy B. Provide basis for measurement of temperature C. Introduces the concept of Entropy, Exergy and Kelvin temperature scale D. Absolute zero temperature 56. Which of the following is the PMM of First kind (I) and It violates the...law of Thermodynamics A. A heat engine which produces energy from nothing and violates the first law B. A heat engine which produces energy from coal and violates the first law C. A heat engine which 100% convert the heat to 100% work and violates the Second law D. A heat engine which 100% heat to 100% work and violates the Third law 57. Which of the following is the PMM of Second kind (II) and It violates the...law of Thermodynamics A. A heat engine which produces energy from nothing and violates the first law B. A heat engine which produces energy from coal and violates the first law C. A heat engine which convert 100% heat to 100% work and violates the Second law D. A heat engine which 100% heat to 100% work and violates the first law 58. According to Clausis statement of second law of thermodynamics A. heat can't be transferred from low temperature source to high temperature source B. heat can be transferred for low temperature to high temperature source by using refrigeration cycle. C. heat can be transferred from low temperature to high temperature source if COP of process is more than unity D. heat can't be transferred from low temperature to high temperature source without the aid of external energy 59. Heat and work are A. point functions B. system properties C. path functions 10

11 D. intensive properties E. extensive properties. 60. Which of the following are path function A. Work and Heat B. Work and Pressure C. Volume and pressure D. Volume and temperature 61. Which of the following are not boundary phenomenon A. Heat Transfer B. Work Transfer C. Mass Transfer D. Change of temperature 62. A system consisting single phase is called A. Closed system B. Heterogeneous system C. Isolated system D. homogenous system 63. An open system is one in which A. mass does not cross boundaries of the system, though energy may do so B. neither mass nor energy crosses the boundaries of the system C. both energy and mass cross the boundaries of the system D. mass crosses the boundary but not the energy 64. An control volume (Open system) in which A. A fixed region in space B. A specified mass C. isolated system D. mass crosses the boundary but not the energy 65. Properties of substances like pressure, temperature and density, in thermodynamic coordinates are A. path functions B. point functions C. cyclic functions D. real functions 66. The door of a running refrigerator inside a room was left open. Which of the following statements is correct? A. The room will be cooled to the temperature inside the refrigerator. B. The room will be cooled very slightly. C. The room will be gradually warmed up. D. The temperature of the air in room will remain unaffected. E. any one of above is possible depending on the capacity. 11

12 67. During throttling process A. heat exchange does not take place B. no work is done by expanding steam C. there is no change of internal energy of steam D. all of the above 68. Barometric pressure is equal to A. 760 mm Hg B. zero mm Hg C mm Hg D. 100mm Hg. 69. An adiabatic wall is one which A. prevents thermal interaction B. permits thermal interaction C. encourages thermal interaction D. discourages thermal interaction 70. If a system after undergoing a series of processes, returns to the initial state then A. process is thermodynamically in equilibrium B. process is executed in closed system cycle C. its entropy will change due to irreversibility D. sum of heat and work transfer will be zero 71 Isochoric (Isometric) process is one in which A. no mechanical work is done by the system B. mass and energy transfer do not take placein a system C. Temperature of system remains constant D. very little mechanical work is done by the system 72 A closed system is one in which A. mass does not cross boundaries of the system, though energy may do so B. mass crosses the boundary but not the energy C. neither mass nor energy crosses the boundaries of the system D. both energy and mass cross the boundaries of the system 73. An isolated system is one in which A. mass does not cross boundaries of the system, though energy may do so B. neither mass nor energy crosses the boundaries of the system C. both energy and mass cross the boundaries of the system D. mass crosses the boundary but not the energy E. thermodynamic reactions do not occur. 74. Which law states that the internal energy of a gas is a function of temperature A. Charles' law B. Joule's law 12

13 C. Regnault's law D. Boyle's law 75.The amount of Heat required to raise the temperature of 1 kg of water through 1degree C A. Specific heat at constant volume B. Specific heat at constant pressure C. Kilo calorie D. none of above 76. Keeping the limitations imposed by the second-law of thermodynamics in mind, choose the wrong statement below: A. A heat engine cannot have a thermal efficiency of 100%. B. For all reversible processes, the second-law efficiency is 100%. C. The second-law efficiency of a heat engine cannot be greater than its thermal efficiency. D. The second-law efficiency of a process is 100% if no entropy is generated during that process. E. The coefficient of performance of a refrigerator can be greater than Two insulated tanks containing ideal gases at different pressure and temperature are connected to each other and gases are allowed to mix. The process that occurs can be called A. Free expansion B. Constant enthalpy C. Constant internal energy D. Reversible adiabatic 78. A balloon containing an ideal gas is initially kept in an evacuated and insulated room. The balloon ruptures and the gas fills up the entire room. Which one of the following statements is TRUE at the end of above process? A. The internal energy of the gas decreases from its initial value, but the enthalpy remains constant B. The internal energy of the gas increases from its initial value, but the enthalpy remains constant C. Both internal energy and enthalpy of the gas remain constant 79. Some MCQ based on Temperature conversion and Identify the correct equation for conversion, COP of Heat pump, refrigerator and efficiency and application of SFEE Type B Question 1. A heat pump is absorbing heat from the cold outdoors at 5 C and supplying heat to a house at 22 C at a rate of 18,000 kj/h. If the power consumed by the heat pump is 2.5 kw, the coefficient of performance of the heat pump is A

1 kg of gas contained in an insulated cylinder expanding as the piston moves slowly outwards. C.

14 B. 1.0 C. 2.0 D. 5.0 Hint: T L =5 ºC T H =22 ºC Q H =18000/3600 kj/s W in =2.5 "kw" COP=Q H /W in if Q H and work given then don't use Temp formula 2. The heat transfer, Q, the work done W and the change in internal energy U are all zero in the case of A. A rigid vessel containing steam at 150 C left in the atmosphere which is at 25 C. B. 1 kg of gas contained in an insulated cylinder expanding as the piston moves slowly outwards. C. A rigid vessel containing ammonia gas connected through a valve to an evacuated rigid vessel, the vessel, the valve and the connecting pipes being well insulated and the valve being opened and after a time, conditions through the two vessels becoming uniform. D. 1 kg of air flowing adiabatically from the atmosphere into a previously evacuated bottle. 3. A 2-kW electric resistance heater in a room is turned on and kept on for 30 min. The amount of energy transferred to the room by the heater is A. 1 kj B. 60 kj C kj D kj E kj Hint:We= 2 kj/s time=30*60 sec Wnet=We*time ΔE=0 Q - W = ΔE Type C Question 1. Following figure indicates an 14

A. Open system. B. Closed system C. Isolated system D. Adiabatic system 2. Following figure indicates an A. Open system. B. Closed system C. Isolated system D. Adiabatic system 2. Following figure indicates an A. Open system. B. Closed system C. Isolated system D. Adiabatic system 3.

Adiabatic system 4. A Fan is running in insulated room as shown in fig. the temperature of the room A. Will decrease with time B. Will increase with time C.

The expansion process is very slow, and is resisted by an ambient pressure of 100 kpa.

15 A. Open system. B. Closed system C. Isolated system D. Adiabatic system 2. Following figure indicates an A. Open system. B. Closed system C. Isolated system D. Adiabatic system 2. Following figure indicates an A. Open system. B. Closed system C. Isolated system D. Adiabatic system 3. Following figure indicates an A. Open system. B. Closed system C. Control volume D. Adiabatic system 2. Following figure indicates an A. Open system. B. Closed system C. Isolated system D. Adiabatic system 4. A Fan is running in insulated room as shown in fig. the temperature of the room A. Will decrease with time B. Will increase with time C. Will constant D. May increase or Decrease Type D Question 1. A gas expands in a frictionless piston-cylinder arrangement. The expansion process is very slow, and is resisted by an ambient pressure of 100 kpa. During the expansion process, the pressure of the system (gas) remains constant at 300 kpa. The change in 15

16 volume of the gas is 0.01 m3. The maximum amount of work that could be utilized from the above process is: A. 0kJ B. 1kJ C. 2kJ D. 3kJ Hint W =p*(change in V) Pressure will be ambient 2. A carnot heat engine receives 500 kj per cycle from a high temperature source of 625 Cand rejects heat to a low temperature sink at 30 C. Determine a. thermal efficiency of this carnot engine b. Amount of heat rejected to the sink per cycle A % and 169 kj B % and 16.4 kj C % and 146 kj D % and 14.6 kj 3. A closed system undergoes a process 1-2 for which the value of W 1-2 &Q 1-2 are 50kJ +20kJ resp. If the system is returned to state 1& the Q 2-1 is -10kJ, the work is: A. -80kJ B. +40kJ C. -20kJ D. -40kJ i.e 20-10=50+W 2 therefore W 2 = An apple with an average mass of 0.18 kg and average specific heat of 3.65 kj/kg. C is cooled from 22 C to 5 C. The amount of heat transferred from the apple is A kj B kj C. -20kJ D kj C=3.65 kj/kg.k m=0.18 kg T1=22 C T2=5 C Q - W = Change in energy (du) du=m*c*(t2-t1) kj 5. Two Carnot heat engines are operating in series such that the heat sink of the first engine serves as the heat source of the second one. If the source temperature of the first engine is 1600 K and the sink temperature of the second engine is 300 K and the thermal efficiencies of both engines are the same, the temperature of the intermediate reservoir is A. 950 K 16

17 B. 693 K C. 860 K D. 473 K Hint: (1600 -T intermediate )/1600 = (T intermediate -300)/ T intermediate 6. In a closed system, volume changes from 1.5m3 to 4.5 m3 and heat addition is 2000 kj. Calculate the Work done, given the pressure volume relation as p ={V 2 }Where p is in kpa and V is in m 3 A kj B J C kj D J Integration of Pdv 17

Where F1 is the force and dl1 is the infinitesimal displacement, but F1 = p1a1

Where F1 is the force and dl1 is the infinitesimal displacement, but F1 = p1a1 In order to force the fluid to flow across the boundary of the system against a pressure p1, work is done on the boundary of the system. The amount of work done is dw = - F1.dl1, Where F1 is the force