McqMate
| 1. |
Which of the following cycle is less efficient as compared to the remaining? |
| A. | Carnot cycle |
| B. | All have identical efficiency |
| C. | Stirling cycle |
| D. | Ericsson cycle |
| E. | Otto cycle |
| Answer» E. Otto cycle | |
| 2. |
The number of degrees of freedom in case of triatomic gases is |
| A. | 5 |
| B. | 3 |
| C. | 6 |
| D. | 4 |
| E. | 2 |
| Answer» C. 6 | |
| 3. |
At critical point the enthalpy of vaporisation is |
| A. | Only dependent on temperature |
| B. | Zero |
| C. | Maximum |
| D. | Minimum |
| E. | None of the above |
| Answer» B. Zero | |
| 4. |
In which of the following case the process of sublimation can occur? |
| A. | Solid nitrogen |
| B. | Solid carbondioxide |
| C. | Liquid air |
| D. | Solid oxygen |
| E. | Sodium |
| Answer» B. Solid carbondioxide | |
| 5. |
Work done in a free expansion process is |
| A. | Negative |
| B. | Positive |
| C. | Maximum |
| D. | Zero |
| E. | Minimum |
| Answer» D. Zero | |
| 6. |
If a system neither exchange mass nor energy with the surroundings, it is known as |
| A. | Semi-closed system |
| B. | Isolated system |
| C. | Inactive system |
| D. | Closed system |
| E. | Segregated system |
| Answer» B. Isolated system | |
| 7. |
Food can be cooked quicker in a pressure cooker because |
| A. | Less heat is lost |
| B. | High pressure steam has high temperature |
| C. | Steam remains within the cooker |
| D. | It is made of a metal |
| E. | None of the above |
| Answer» C. Steam remains within the cooker | |
| 8. |
A surface which diffusely reflects and emits tha same amount of energy which it receives by radiation, is known as |
| A. | A perfect surface |
| B. | A perfect grey surface |
| C. | A perfect white surface |
| D. | A perfect radiating surface |
| E. | None of the above |
| Answer» D. A perfect radiating surface | |
| 9. |
Exhaust gases from a engine possess |
| A. | Chemical energy |
| B. | Solar energy |
| C. | Potential energy |
| D. | Stored energy |
| E. | Kinetic energy |
| Answer» E. Kinetic energy | |
| 10. |
Which one of the following is an indirect reaction device? |
| A. | Turbojet |
| B. | Ramjet |
| C. | Pulsejet |
| D. | Propeller |
| E. | All of the above |
| Answer» D. Propeller | |
| 11. |
Cetane number of a diesel fuel is a measure of its |
| A. | volatility |
| B. | Pulsejet |
| C. | delay period |
| D. | viscosity |
| E. | ignition quality |
| Answer» E. ignition quality | |
| 12. |
A thermistor is a |
| A. | Thermocouple |
| B. | Thermometer |
| C. | Thermos flask |
| D. | Miniature resistance |
| E. | None of the above |
| Answer» D. Miniature resistance | |
| 13. |
Which of the following is a reversible process? |
| A. | Extension and compression of a spring |
| B. | Diffusion |
| C. | Free expansion |
| D. | Throttling |
| E. | Combustion |
| Answer» A. Extension and compression of a spring | |
| 14. |
Power required for the engine is |
| A. | 7.75 kW |
| B. | 8.88 kW |
| C. | 9.23 kW |
| D. | 6.60 kW |
| E. | Pulsejet |
| Answer» C. 9.23 kW | |
| 15. |
According to Charle's law |
| A. | At constant pressure the volume of a gas is proportional to its temperature |
| B. | At constant pressure the volume of a gas is proportional to its absolute temperature |
| C. | At constant gauge pressure the molecular folume of a gas is proportional to its absolute temperature |
| D. | At constant volume the absolute pressure is proportional to absolute temperature |
| E. | None of the above |
| Answer» A. At constant pressure the volume of a gas is proportional to its temperature | |
| 16. |
The mean free path of a gas least depends on |
| A. | volume of gas |
| B. | viscosity of gas |
| C. | Pulsejet |
| D. | density of gas |
| E. | pressure of gas |
| Answer» A. volume of gas | |
| 17. |
The value of universal gas constant in S.I. units is |
| A. | 831.4 J/kg mole/?k |
| B. | 8314 J/kg mole/?k |
| C. | 8.314 J/kg mole/?k |
| D. | 83.14 J/kg mole/?k |
| E. | 0.8314 J/kg mole/?k |
| Answer» B. 8314 J/kg mole/?k | |
| 18. |
Which of the following valve is installed between the boiler and the feed pump? |
| A. | Flow of c*ck |
| B. | Pulsejet |
| C. | Steam stop valve |
| D. | Throttle valve |
| E. | Feed check valve |
| Answer» E. Feed check valve | |
| 19. |
Thermodynamic equilibrium is completely defined by the specifications of |
| A. | Internal energy |
| B. | Enthalpy |
| C. | Generalized displacements |
| D. | All the above together |
| E. | None of the above |
| Answer» D. All the above together | |
| 20. |
A gas (inversion temperature Ti) undergoing Joule Thomson expansion at temperature T will produce cooling effect only when |
| B. | Ti < T |
| C. | Ti > T |
| D. | Pulsejet |
| E. | Ti = T |
| Answer» B. Ti < T | |
| 21. |
During an adiabatic expansion, the increase in volume is associated with |
| A. | decrease in pressure and increase in temperature |
| B. | increase in pressure and decrease in temperature |
| C. | Decrease in pressure and decrease in temperature |
| D. | Pulsejet |
| E. | increase in pressure and increase in temperature |
| Answer» C. Decrease in pressure and decrease in temperature | |
| 22. |
The mean free path of a gas molecule increases with |
| A. | increase in pressure |
| B. | increase in density |
| C. | increase in temperature |
| D. | Pulsejet |
| E. | decrease in temperature |
| Answer» C. increase in temperature | |
| 23. |
In a Carnot cycle the heat is rejected at |
| A. | Constant pressure |
| B. | Constant temperature |
| C. | Constant entropy |
| D. | Constant enthalpy |
| E. | Constant volume |
| Answer» B. Constant temperature | |
| 24. |
Which of the following statement is incorrect? |
| A. | Total heat of steam is less than the total weight of dry and super saturated steam |
| B. | Total heat of super heated steam is more than the total heat of wet steam |
| C. | Latent heat of steam at critical pressure is zero |
| D. | Latent heat per kg of steam decreases as the pressure of steam increases |
| E. | None of the above |
| Answer» D. Latent heat per kg of steam decreases as the pressure of steam increases | |
| 25. |
Non-dimensional numbers generally involved in case of heat transfer from horizontal cylinders by natural convection are |
| A. | Reynolds number |
| B. | Nusselt number |
| C. | Prandtl number |
| D. | Grashof number |
| E. | (B), (C) and (D) above |
| Answer» E. (B), (C) and (D) above | |
| 26. |
Which of the following is the best fuel for diesel engines? |
| A. | Olefins |
| B. | Pulsejet |
| C. | Aromatics |
| D. | Naphthenes |
| E. | Paraffins |
| Answer» E. Paraffins | |
| 27. |
Air leaking from a punctured tube is an example of |
| A. | Throttling |
| B. | Constant volume expansion |
| C. | Adiabatic expansion |
| D. | Constant pressure expansion |
| E. | Isothermal expansion |
| Answer» A. Throttling | |
| 28. |
The percentage of carbondioxide in the exhaust gases from a diesel engine cannot exceed |
| A. | 40% |
| B. | 50.50% |
| C. | 29% |
| D. | 36% |
| E. | 55% |
| Answer» C. 29% | |
| 29. |
Internal energy of a perfect gas depends on |
| A. | Temperature, specific heats and entropy |
| B. | Temperature, specific heats and pressure |
| C. | Temperature, specific heats and enthalpy |
| D. | Temperature and specific heats |
| E. | Temperature only |
| Answer» E. Temperature only | |
| 30. |
The process during which external work done is not zero, is |
| A. | Constant volume process |
| B. | Constant pressure process |
| C. | Throttling |
| D. | Free expansion |
| E. | All of the above |
| Answer» B. Constant pressure process | |
| 31. |
Which of the following cycle consists of two isothermal and constant volume processes? |
| A. | Joule cycle |
| B. | Diesel cycle |
| C. | Rankine cycle |
| D. | Otto cycle |
| E. | Ericsson cycle |
| Answer» E. Ericsson cycle | |
| 32. |
A perfect black body is |
| A. | One which absorbs all radiant energy at all wavelengths |
| B. | One which does not reflect the radiant energy |
| C. | Black in colour |
| D. | One through which radiant energy is not transmitted |
| E. | One which absorbs total radiant energy |
| Answer» A. One which absorbs all radiant energy at all wavelengths | |
| 33. |
The characteristics of a control volume are |
| A. | There is no material flow across the boundary |
| B. | The volume, shape and position with respect to an observer may change |
| C. | Pulsejet |
| D. | The volume, shape and position with respect to an observer are fixed |
| Answer» D. The volume, shape and position with respect to an observer are fixed | |
| 34. |
By doubling the temperature the radiant heat will increase |
| A. | 16 times |
| B. | microns |
| C. | 4 times |
| D. | 8 times |
| E. | 2 times |
| Answer» A. 16 times | |
| 35. |
Which of the following is not a property of the system |
| A. | Temperature |
| B. | Pressure |
| C. | Specific volume |
| D. | Heat |
| E. | None of the above |
| Answer» D. Heat | |
| 36. |
The mixture formation in a carburettor is based on the principle of |
| A. | Venturi principle |
| B. | Pascal's law |
| C. | Law of vapours |
| D. | Daltons law |
| E. | Newtons law of motion |
| Answer» A. Venturi principle | |
| 37. |
Heating wet steam at constant temperature is same as heating at |
| A. | Constant pressure |
| B. | Constant volume |
| C. | Constant enthalpy |
| D. | Constant entropy |
| E. | None of the above |
| Answer» A. Constant pressure | |
| 38. |
A liquid flowing through a tube is turbulent. In which case will the maximum change in heat transfer coefficient occur? |
| A. | Diameter of the tube is increased 4 time maintaining the ratio of liquid flow constant |
| B. | Diameter of the tube is increased 4 times maintaining the velocity of flow constant |
| C. | Diameter of the tube is increased 2 times maintaining the rate of liquid flow constant |
| D. | Diameter of the tube is increased 2 times maintaining the velocity of flow constant |
| E. | microns |
| Answer» A. Diameter of the tube is increased 4 time maintaining the ratio of liquid flow constant | |
| 39. |
All of the following cycles consists of two isothermal processes EXCEPT |
| A. | Ericsson cycle |
| B. | Stirling cycle |
| C. | Brayton cycle |
| D. | Carnot cycle |
| E. | Pulsejet |
| Answer» C. Brayton cycle | |
| 40. |
Which of the following introduces irreversibility in the actual Carnot engine operation? |
| A. | Higher operating speeds |
| B. | Losses from working fluid in transit |
| C. | Pulsejet |
| D. | Changes in pressure and temperature during the cycle |
| E. | Friction between moving parts |
| Answer» B. Losses from working fluid in transit | |
| 41. |
Which of the following is the best fuel for S.I. engines? |
| A. | Naphthenes |
| B. | Olefins |
| C. | Aromatics |
| D. | Pulsejet |
| E. | Paraffins |
| Answer» C. Aromatics | |
| 42. |
The cycle generally used for gas turbines is |
| A. | Brayton cycle |
| B. | Carnot cycle |
| C. | Dual cycle |
| D. | Otto cycle |
| E. | Rankine cycle |
| Answer» A. Brayton cycle | |
| 43. |
The slope of constant pressure line on temperature entropy diagrm is given by |
| A. | 90? |
| B. | T/Cp |
| C. | Cp/T |
| D. | S/T |
| E. | T/S |
| Answer» B. T/Cp | |
| 44. |
In automobiles clutch is mounted between |
| A. | Gear box and differential |
| B. | Differential and wheels |
| C. | Engine and flywheel |
| D. | Engine and differential |
| E. | Flywheel and gear box |
| Answer» E. Flywheel and gear box | |
| 45. |
During an adiabatic process the change in entropy is |
| A. | Positive or Negative |
| B. | Zero |
| C. | Negative |
| D. | Approximately zero |
| E. | Positive |
| Answer» B. Zero | |
| 46. |
The behaviour of which of the following vapour is closer to that of a gas? |
| A. | Wet vapour |
| B. | Wet and superheated vapours |
| C. | Wet and dry vapour |
| D. | Superheated vapour |
| E. | Dry vapour |
| Answer» D. Superheated vapour | |
| 47. |
The ratio of the rise in temperature of a gas when compressed adiabatically to that when compressed isothermally to the same extent is |
| A. | Depends on the gas |
| B. | Pulsejet |
| C. | less than 1 |
| D. | Equal to 1 |
| E. | More than 1 |
| Answer» E. More than 1 | |
| 48. |
In all irreversible processes, the entropy of the system |
| A. | Increases |
| B. | Depends on medium |
| C. | Remains constant |
| D. | Sometimes increases and sometimes decreases |
| E. | Reduces to zero |
| Answer» A. Increases | |
| 49. |
Which of the following remains constant during an adiabatic process? |
| A. | internal energy |
| B. | enthalpy |
| C. | entropy |
| D. | All of the above |
| E. | Pulsejet |
| Answer» C. entropy | |
| 50. |
Reduced pressure is |
| A. | dimensionless |
| B. | an index of molecular position of gas |
| C. | always unity |
| D. | Pulsejet |
| E. | always less than atmospheric pressure |
| Answer» A. dimensionless | |
| 51. |
In the polytropic process equation pvn = constant, if the value of n is infinitely large the process is termed as |
| A. | Adiabatic |
| B. | Constant volume |
| C. | Isothermal |
| D. | Constant pressure |
| E. | Constant temperature |
| Answer» B. Constant volume | |
| 52. |
The ratio of the rise in temperature of a gas when compressed adiabatically to that when compressed isothermally to the same extent is |
| A. | More than 1 |
| B. | Less than 1 |
| C. | Equal to 1 |
| D. | Depends on the gas |
| E. | None of the above |
| Answer» A. More than 1 | |
| 53. |
Other factors remaining constant, if the temperature of sink is increased, the efficiency of the Carnot engine will |
| A. | increase or decrease depending upon temperature ratio |
| B. | will not change |
| C. | Pulsejet |
| D. | increase |
| E. | decrease |
| Answer» E. decrease | |
| 54. |
One of the most efficient engines ever developed operates between 2100 k and 700 k. Its actual efficiency is 40%. What percentage of its maximum possible efficiency is this? |
| A. | 40% |
| B. | 33.30% |
| C. | 60% |
| D. | Pulsejet |
| E. | 66.67% |
| Answer» C. 60% | |
| 55. |
For any reversible process, the change in entropy of the system and surroundings is |
| A. | Negative |
| B. | Zero |
| C. | Unity |
| D. | Infinite |
| E. | Positive |
| Answer» B. Zero | |
| 56. |
If all the variables of a steam are in-dependent of time it is said to be in |
| A. | Unsteady flow |
| B. | Uniform flow |
| C. | Steady flow |
| D. | Closed flow |
| E. | Constant flow |
| Answer» C. Steady flow | |
| 57. |
Entropy of mixing is always |
| A. | positive |
| C. | Zero |
| D. | Negative |
| E. | Pulsejet |
| Answer» A. positive | |
| 58. |
A system comprising a single phase is called a |
| A. | Open system |
| B. | Isolated system |
| C. | Closed system |
| D. | Homogeneous system |
| E. | Heterogeneous system |
| Answer» D. Homogeneous system | |
| 59. |
An open system |
| A. | Is a specified region where transfers of energy and/or mass take place |
| B. | Is a region of constant mass and only energy is allowed to cross the boundaries |
| C. | Cannot transfer either energy or mass to or from the surroundings |
| D. | Has a mass transfer across its boundaries, and the mass within the system is not necessarily constant |
| E. | None of the above |
| Answer» D. Has a mass transfer across its boundaries, and the mass within the system is not necessarily constant | |
| 60. |
In the regenerative cycle |
| A. | Power is generated in two stages |
| B. | Part of the steam is withdrawn from the turbine and is utilised in heating the exhaust steam |
| C. | Steam is reheated after expansion and again used |
| D. | Part of the steam is withdrawn from the turbine and is used in heating the steam being supplied to the turbine |
| E. | Part of the steam is withdrawn from the turbine and is used in heating the feed water |
| Answer» E. Part of the steam is withdrawn from the turbine and is used in heating the feed water | |
| 61. |
Which of the following is a path function quantity? |
| A. | Work done |
| B. | Pressure |
| C. | Pulsejet |
| D. | Temperature |
| E. | Enthalpy |
| Answer» A. Work done | |
| 62. |
An ordinary mercury thermometer can be used for temperatures about |
| A. | 200?C |
| B. | 400?C |
| C. | 300?C |
| D. | 100?C |
| E. | 500?C |
| Answer» C. 300?C | |
| 63. |
Triple point |
| A. | Occurs in sublimation |
| B. | Occurs in a mixture of two or more gases |
| C. | Is the range of temperature within which three constituents simultaneously change phase |
| D. | Is that point where three phases solid, liquid and gas exist together |
| E. | None of the above |
| Answer» D. Is that point where three phases solid, liquid and gas exist together | |
| 64. |
The characteristics of a control volume are |
| A. | The volume shape and position with respect to an observer may change |
| B. | The volume shape and position with respect to an observer are fixed |
| C. | There is no material flow across the boundary |
| D. | Pulsejet |
| E. | There is material flow across the boundary |
| Answer» E. There is material flow across the boundary | |
| 65. |
The gas turbine works on |
| A. | Rankine cycle |
| B. | Brayton cycle |
| C. | Erricson cycle |
| D. | Otto cycle |
| E. | Carnot cycle |
| Answer» B. Brayton cycle | |
| 66. |
All of the following are intensive properties EXCEPT |
| A. | Viscosity |
| B. | Mass |
| C. | Pulsejet |
| D. | Density |
| E. | Temperature |
| Answer» B. Mass | |
| 67. |
A body of weight 100 N falls freely through a distance of 10 m against an atmospheric drag force of 5 N. Considering the body as the system, the work interaction is |
| A. | 1000 Nm |
| B. | Pulsejet |
| C. | 1050 Nm |
| D. | 50 Nm |
| E. | 950 Nm |
| Answer» D. 50 Nm | |
| 68. |
In a steam turbine when steam expands, the entropy |
| A. | Decreases exponentially |
| B. | Does not change |
| C. | Increases exponentially |
| D. | Decreases linearly |
| E. | Increases linearly |
| Answer» B. Does not change | |
| 69. |
Of the following first law statements, choose the one that is wrong |
| A. | the net heat transfer equals the network for a cycle |
| B. | the heat transfer equals the work plus the energy change |
| C. | the heat transfer cannot exceed the work done |
| D. | Pulsejet |
| E. | the energy of an isolated system remains constant |
| Answer» C. the heat transfer cannot exceed the work done | |
| 70. |
If the dryness fraction of a sample by throttling calorimeter is 0.8 and that by separating calorimeter is also 0.8, then the actual dryness fraction of sample will be taken as |
| A. | Volume change is negligible |
| B. | 1 |
| C. | 0.8 |
| D. | 0.5 |
| E. | 0.64 |
| Answer» E. 0.64 | |
| 71. |
Work done by an expanding gas under adiabatic condition results in |
| A. | Temperature decrease |
| B. | Temperature decreases first and then increase |
| C. | Temperature increase first and then decrease |
| D. | No change in temperature |
| E. | Temperature increase |
| Answer» A. Temperature decrease | |
| 72. |
Carburetted water gas is obtained by |
| A. | heating water at high temperature in a copper vessel |
| B. | Burning oil |
| C. | spraying oil into a carburettor filled with hot brick elieckar work through which the gases pass |
| D. | Pulsejet |
| E. | Passing alternately steam and air through while hot carbon |
| Answer» E. Passing alternately steam and air through while hot carbon | |
| 73. |
A process which does not dissipate available energy is known as |
| A. | Isothermal process |
| B. | Energyless process |
| C. | Adiabatic process |
| D. | Ideal process |
| E. | Frictionless process |
| Answer» D. Ideal process | |
| 74. |
The weight of 1 cu-m of carbon dioxide at NTP if the characteristic gas constant is 19.28 kg metre/kg/?C, would be |
| A. | 3.924 kg |
| B. | 2.5 kg |
| C. | 1.962 kg |
| D. | 1 kg |
| E. | 1.5 kg |
| Answer» C. 1.962 kg | |
| 75. |
The ability of gasoline to resist detonation during combustion is given by |
| A. | iso-octane number |
| B. | heptane number |
| C. | Pulsejet |
| D. | Cetane number |
| E. | Octane number |
| Answer» E. Octane number | |
| 76. |
"The internal energy of a gas is a function of temperature". Which of the following name is associated with the above law? |
| A. | Regnault |
| B. | Dalton |
| C. | Boyle |
| D. | Charle |
| E. | Joule |
| Answer» E. Joule | |
| 77. |
The solubility of a gas in a liquid at small concentration is represented by |
| A. | Joules equation |
| B. | Van der Waal's equation |
| C. | Henry's law |
| D. | Claperyon equation |
| E. | Roults law |
| Answer» C. Henry's law | |
| 78. |
A scavenging pump is used in |
| A. | Pulsejet |
| B. | vapour compression cycles |
| C. | two stroke spark ignition engines |
| D. | steam engines |
| E. | four stroke compression ignition engines |
| Answer» C. two stroke spark ignition engines | |
| 79. |
The difference between two specific heats of a gas is equal to universal constant when |
| A. | 1 mole of gas is heated |
| B. | 1 gm molecule of gas is heated |
| C. | 1 gm of gas is heated |
| D. | Pulsejet |
| E. | any amount of gas is heated |
| Answer» B. 1 gm molecule of gas is heated | |
| 80. |
Which of the following is a non-petroleum fuel? |
| A. | Diesel oil |
| B. | Petrol |
| C. | Naphtha |
| D. | Alcohol |
| E. | All of the above |
| Answer» D. Alcohol | |
| 81. |
The average pressure on the walls of a vessel will be doubled if the |
| A. | average velocity of the molecules in it is doubled |
| B. | the number of molecules in the vessel is doubled |
| C. | Pulsejet |
| D. | the mass of each molecule is halved |
| E. | the mass of each molecule is doubled |
| Answer» B. the number of molecules in the vessel is doubled | |
| 82. |
The fastest moving gas molecules are those of |
| A. | Pulsejet |
| B. | Oxygen |
| C. | Hydrogen |
| D. | Nitrogen |
| E. | Chlorine |
| Answer» C. Hydrogen | |
| 83. |
which of the following set of quantities contains intensive variables? |
| A. | Kinetic energy, potential energy and internal energy |
| B. | Pulsejet |
| C. | Work, energy and weight |
| D. | Mass, volume and area |
| E. | Pressure, temperature and density |
| Answer» E. Pressure, temperature and density | |
| 84. |
A system |
| A. | Is a specified region, not necessarily of constant volume, where transfer of energy and/or mass are to be studied |
| B. | Is a region of constant mass and only energy is allowed to cross the boundaries |
| C. | Cannot transfer either energy or mass to or from the surroundings |
| D. | Has a mass transfer across its boundaries and the mass within the system is not constant |
| E. | None of the above |
| Answer» A. Is a specified region, not necessarily of constant volume, where transfer of energy and/or mass are to be studied | |
| 85. |
Transformer oil having kinematic viscosity of 3.66 x 10-6 m2/s flows through a tube 8 mm diameter at velocity of 0.6 m/s. The value of Reynolds number of flow would be |
| A. | 1510 |
| B. | 1000 |
| C. | 1600 |
| D. | 1415 |
| E. | 1310 |
| Answer» E. 1310 | |
| 86. |
An isentropic process is always |
| A. | Irreversible and adiabatic |
| B. | Reversible and isothermal |
| C. | Frictionless and irreversible |
| D. | Reversible and adiabatic |
| E. | None of the above |
| Answer» D. Reversible and adiabatic | |
| 87. |
In a reversible polytropic process |
| A. | The entropy remains constant |
| B. | Some heat transfer occurs |
| C. | The internal energy remains constant |
| D. | The temperature remains constant |
| E. | The ethalpy remains constant |
| Answer» A. The entropy remains constant | |
| 88. |
A gas which obeys kinetic theory perfectly is known as |
| A. | Monoatomic gas |
| B. | Perfect gas |
| C. | Diatomic gas |
| D. | Real gas |
| E. | Pure gas |
| Answer» B. Perfect gas | |
| 89. |
An automobile heats up while lying in a parking 10 ton a sunny day. The process can be assumed to be |
| A. | isothermal |
| B. | isometric |
| C. | isobaric |
| D. | Pulsejet |
| E. | isentropic |
| Answer» C. isobaric | |
| 90. |
The efficiency of a Carnot engine is given as 0.75. If the cycle direction is reversed, what will be the value of COP of reversed Carnot cycle |
| A. | 0.33 |
| B. | 0.25 |
| C. | 1.33 |
| D. | 0.75 |
| E. | 4 |
| Answer» A. 0.33 | |
| 91. |
Which rays have the least wavelength? |
| A. | Infra-red |
| B. | Ultraviolet |
| C. | Radio |
| D. | Cosmic rays |
| E. | X-rays |
| Answer» D. Cosmic rays | |
| 92. |
The difference between two specific heats of a gas is equal to universal gas constant |
| A. | When 1 gm molecule heated |
| B. | When 1 molecule of gas is heated |
| C. | When 1 gm molecule heated |
| D. | When 1 gm of gas is heated |
| E. | When any amount of gas is heated |
| Answer» C. When 1 gm molecule heated | |
| 93. |
1 cu-m of steam having dryness franction 0.85 at 12 ata mixes with 1.5 kg of water at 12?C at constant pressure. The dryness fraction of resulting steam would be |
| A. | 0.6 |
| B. | 0.5 |
| C. | 0.85 |
| D. | 0.637 |
| E. | 0.75 |
| Answer» D. 0.637 | |
| 94. |
In centrifugal compressors, the ratio of outlet whirl velocity to blade velocity at outlet is known as |
| A. | Feedback factor |
| B. | Slip factor |
| C. | Reheat factor |
| D. | Gauge factor |
| E. | Velocity factor |
| Answer» B. Slip factor | |
| 95. |
In case of centrifugal compressors the phenomenon of unsteady, periodic and reversed flow is known as |
| A. | Surging |
| B. | Stalling |
| C. | Choking |
| D. | Either of above |
| E. | None of the above |
| Answer» A. Surging | |
| 96. |
A Rankine cycle working with saturated steam differs thermodynamically from a Carnot cycle only in the fact that |
| A. | The Carnot cycle cannot be used for vapour |
| B. | Steam is not the working substance for Carnot cycle |
| C. | There are more than two sources of heat in Rankine cycle |
| D. | Heat is supplied to the water at temperatures below the maximum temperature of the cycle |
| E. | None of the above |
| Answer» D. Heat is supplied to the water at temperatures below the maximum temperature of the cycle | |
| 97. |
In case of ideal triatomic gas, the ratio of specific heats Cp/Cv would be |
| A. | 1 |
| B. | 1.33 |
| C. | 1.4 |
| D. | 1.41 |
| E. | 1.67 |
| Answer» B. 1.33 | |
| 98. |
During adiabatic expansion which of the following remains constant |
| A. | Internal energy |
| B. | Temperature |
| C. | Entropy |
| D. | None of the above |
| E. | Pulsejet |
| Answer» C. Entropy | |
| 99. |
Which of the following is a boiler accessory? |
| A. | Water level indicator |
| B. | Economiser |
| C. | Pulsejet |
| D. | Stop valve |
| E. | Fusible plug |
| Answer» B. Economiser | |
| 100. |
Draught ensures supply of |
| A. | Air for combustion |
| B. | Feed water |
| C. | Coad to the boiler |
| D. | Superheated steam |
| E. | Isothermal |
| Answer» A. Air for combustion | |
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