(i) they receive heat from a source 16. Which of the following sentence(s) is(are)correct about the heat engines? (ii) they convert part of this heat to work (iv) they operate in a cycle (iii) they reject heat to a sink B) (i) only C) (iii) and (iv) only D) All of the above and (iv) only 17. Which of the following sentence is incorrect about Carnot cycle: A) undergoes a series of four internally reversible processes. B) Camot cycle demonstrates the minimum conversion of heat into work C) The efficiency of an irreversible heat engine is always less than the efficiency of a reversible one operating between the same two reservoirs D) The theoretical heat engine that operates on the Carnot cycle is called the Camol's heat engine C) (Temperature, pressure,density) D) (heat,temperature, pressure) 19. The following quantities state functions: A) (internal energy, entropy enthalpy) B) (heat, density, entropy) C) (work, pressure, Gibbs free energy) D) (heat, temperature,pressure) 18. The following properties are intensive properties;A) (mass, entropy, enthalpy) B) (number of mole density, work) A) Chemical equilibrium at 100-C,3.0MPa obtained using the compressibility factor (Z-0.6T) C) 0.00679L/kg D) 0.00679m^3/kg 21. The specific volume of R-134a (MW=102.03g/mol) 20.Thermodynamics equilibrium implies: C) mechanical equilibrium D) All the above B) Thermal equilibrium is: A) 6,79m^3/kg B) 0.00679m^3 22. A tank containing a fluid is stimed by a paddle wheel. The work input to the paddle wheel is 5090 kJ If the heat transfer from the tank is 1500 kJ, the change in internal energy is:A) -3,590kJ B) 6,590 kJ C)3.590 kJ D) -6,590kJ 23. If the pressure of 1 kg of an ideal gas dropped from 200 to 150kPa when it is heated from 300 to 1500 K, the entropy change is (Cp=0.922kJ/kg/K ): A) 1.5586kJ/kg/K B) 1.5568J/kg/K C) -1.5586kJ/g/K D) 1.8365kJ/kg/^circ C 24. The volume of a high altitude chamber is 40m^3 It is put into operation by reducing pressure from 1 bar to 0.4 bar and temperature from 25^circ C to 5^circ C How many kg of air must be removed from the chamber during the process assuming ideal gas behavior? A) 26,710kg B)26,710 g D) Data are not enough C) 0 kg 15. One kilogram of liquid water is heated from 20cdot C to 90-C The entropy change is (Cp=4.184kJ/kg/K) A) 895,8 JKkg B) 895.8J/K/kg C) 0.8958J/K/kg D) none of the above 26. A vessel having a volume of 5m^3 contains 0.05m^3 of saturated liquid water and 4.95m^3 of saturated water vapor at 0.1 MPa is heated until the vessel is filled with saturated vapor and the change in internal energy is 104935 kJ. Determine total mass of the saturated mixture, its quality and the amount of heat it received are (at0.1MPa,v_(f)=0.001043m^3/kg and v_(g)= 1.6940m^3/kg ): A) (50.86kg;5.7% ;104935kJ) B) (47.93kg;6% ;-104935kJ) C) (50.86kg;6% : 132261 kJ) (47.93kg;5.7% ;-104935kJ) 27. A 50-kg iron block (C_(p)=0.45kJ/kg^circ C) lat 80^circ C is dropped into an insulated tank that contains 500 kg of liquid water (C_(p)-4.18kJ/kg)^circ C at 25^circ C The temperature when thermal equilibrium is reached is: A) 25,6^circ C {}^circ C D) -20.9^circ C B) 25.6^circ C C) 29.1 28. Air is flowing in a 0.2-m-diameter pipe at a uniform velocity of 0.1m/s The temperature is 25^circ C and the pressure is 150 kPa. Determine the mass flow rate. A) 5.5kg/s B) 0.55kg/s C) 5.70g/s D) 5.5g/s 29. Steam at 0.6MPa and 200circ C enters an insulated nozzle with a velocity of 50m/s It leaves at a pressure of 0.15 MPa and a velocity of 600m/s The change in enthalpy of the stream is:A) -178.7kJ/kg B) 178.7J/kg C) 178.7kJ/g D) 178.7kJ/kg 30. Nitrogen gas is compressed in a steady-state.steady-flow, adiabatic process from 0.1 MPa, 25^circ C During the compression process the temperature become 125^circ C Determine the work done on the nitrogen in kW if the mass flow rate is 0.2kg/s and the change in enthalpy 103.9kJ/kg: A) 0.0 B) -103.9 C) 20.78 D) 519.5 31. For a given pressure the vapor become saturated when it's temperature is A) equal to the saturated temperature B) lower than it's saturated temperature C)is higher than it's saturated temperature D) None of the above 32. In the stream tables, properties of substances are arranged as function of : A) temperature and pressure B) Pressure and volume C) Volume and entropy D) specific volume and temperature 33. The state of 10 kg of water at 120^circ C contain in a rigid container of volume 0.5m^3(v_(f)=0.00106m^3/kg;v_(g)= 0.08908m^3/kg at 120^circ C is: A) Compressible liquid B) Saturated liquid C)saturated mixture D)superheated vapor 34. The mass of the vapor in 5 kg of water saturated mixture at 200^circ C contain in a vessel of 0.04m^3(v_(f)=0.0011m^3/kg i v_(g)=0.12m^3/kg200^circ C) is: A) 0.78 kg B) 0.29 kg C) 2.1 kg D) 4508 35. The specific enthalpy (in kJ/kg) of a pure substance at 8 MPa and 400^circ C is having a specific internal energy of 2864 kJ/kg and a specific volume 0.03432m^3/kg is: A) 3.139times 10^3 B) 3.931times 10^-3 D) 3.139 C) 3139times 10^3