Which one is correct for throttling process () Internal energy remains constant () Entropy remains constant () Pressure remains constant () Enthalpy remains constant () Temperature remains constant 2. A heat engine receives heat from a source at 7, heat is supplied to this engine at a rate of Q, 100 () 25.4 kW () 55.4 kW ( ) 74.6 KW 3. The area under the P-V curve represents; () Pressure drop 1273 K and rejects the waste heat to a sink at T- 323 K. kJ/s, the maximum power this heat engine can produce is () 100.0 kW ( ) 95.0 kW () Heat gain () Boundary work () Density of the fluid () Efficiency of the cycle 4. Which one is correct for heat pump cycle; ( ) COP,<COP ( ) COP COP+1 ( ) COP,-COP ( ) COP-COP,+1 () None 5. A heat pump is absorbing heat from the cold outdoors at 5°C and supplying heat to a house at 25°C at a rate of kW. If the power consumed by the heat pump is 1.9 kW, the coefficient of performance of the heat pump is () 1.3 ( ) 2.6 () 3.0 ( ) 3.8 ( ) 13.9 6. A 300-m³ rigid tank is filled with saturated liquid-vapor mixture of water at 200 kPa. If 25% of the mass is liqu and the 75% of the mass is vapor, the total mass in the tank is () 451 kg ( ) 556 kg ( ) 300 kg () 331 kg () 195 kg 7. According to ............. it is impossible to construct a device that operates in a cycle and produces no effect of than the transfer of heat from a lower-temperature body to a higher-temperature body. ( ) Carnot Statement ( ) Kelvin Planck Statement ( ) Conservation of energy () Clausius statement () First Law of Thermodynamics 8. A piston-cylinder device contains air. During a quasi-equilibrium isothermal (AU-0) expansion process, 15 boundary work is done by the system, and 3 kJ of paddle-wheel work is done on the system. The heat tra during this process is ( ) 12 kJ ( ) 18 kJ ( ) 2.4 kJ () 3.5 kJ () 60 kJ 9. Steam is compressed by an adiabatic compressor from 0.2 MPa and 150°C to 25 MPa and 500°C at a r 1.30 kg/s. The power input to the compressor is: ( ) 344 kW ( ) 428 kW ( ) 516 kW ()717 kW () 901 kW 10. An adiabatic heat exchanger is used to heat cold water at 15°C entering at a rate of 5 kg/s by hot air at 90°C entering also at rate of 5 kg/s. If the exit temperature of hot air is 20°C, the exit temperature of cold water is: (Consider C4.18 kJ/kg K and Cor = 1 kJ/kg.K) () 27 °C () 32°C () 52°C () 85°C () 90 °C 11. Water is boiling at 100 kPa pressure in a stainless steel pan on an electric range. It is observed that 2 kg of liquid water evaporates in 30 minutes. The rate of heat transfer to the water is () 3.12 kW () 2.32 kW () 2.97 kW () 0.47 kW ()2.51 KW 12. A 6-pack canned drink is to be cooled from 18 °C to 3 "C. The mass of each canned drink is 0.355 kg. The drinks can be treated as water, and the energy stored in the aluminum can itself is negligible. The amount of heat transfer from the 6 canned drinks is (Assume Cowar 4.18 kJ/kg.K) () 22 kJ ( ) 32 kJ () 134 kJ () 187 kJ ( ) 223 kJ 13. In a heating system, cold outdoor air at 7 °C flowing at a rate of 4 kg/min is mixed adiabatically with heated air at 70 °C flowing at a rate of 3 kg/min. The exit temperature of the mixture is; (assume constant c, for water) ( ) 34°C ( ) 39°C ( ) 45 °C ()63°C ( )77°C 14. Steam expands in a turbine from 4 MPa and 500°C to 0.5 MPa and 250 °C at a rate of 0.375 kg/s. Heat is lost from the turbine at a rate of 25 kJ/s during the process. The power output of the turbine is; ( ) 246 kW () 207 kW () 182 kW () 287 kW ( ) 157 kW 15. Air is to be heated steadily by an 8-kW electric resistance heater as it flows through an insulated duct. If the air enters at 50°C at a rate of 2 kg/s, the exit temperature of air will be (assume Car 1 kJ/kg.K) ( ) 46.0°C ( ) 50.0°C ( ) 54.0°C ( ) 55.4°C ( ) 58.0°C 16. A rigid 3-m³ rigid vessel contains steam at 4 MPa and 500 °C. The mass of the steam is; ( ) 3 kg ( ) 9 kg ( ) 26 kg () 35 kg () 52 kg 17. The drinking water needs of an office are met by cooling tab water in a refrigerated water fountain from 23°C to 6 "C at an average rate of 10 kg/h. If the COP of this refrigerator is 3.1, the required power input (W) to this refrigerator is; (assume Cat 4.18 kJ/kg.K) ( ) 197 W ()612 W () Pump 18. In thermal power plants... ( ) Nozzle ( ) 64 W ( ) 109 W ( ) 403 W is used to convert thermal energy of the fluid to mechanical shaft work () Heat exchanger ( ) Compressor ( ) Turbine