MCQOPTIONS
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MCQOPTIONS
This section includes 460 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Engines knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Dissociation is |
| A. | Process of heat liberation in which no flame exist |
| B. | Same is combustion |
| C. | Combustion without heat |
| D. | Slow combustion |
| E. | Smokeless combustion |
| Answer» C. Combustion without heat | |
| 52. |
The capacity of an automobile battery is expressed in terms of |
| A. | Number of cells |
| B. | Number of plate |
| C. | Ampere hours |
| D. | Amperes |
| E. | Voltage |
| Answer» D. Amperes | |
| 53. |
Speed drop is the |
| A. | Drop in engine speed |
| B. | Increasing in engine speed |
| C. | Reduction in engine speed from no loads to full load |
| D. | Change in engine speed while fuel supply remains the same |
| E. | None of the above |
| Answer» D. Change in engine speed while fuel supply remains the same | |
| 54. |
Which of the following type of internal combustion engines uses rocker arms? |
| A. | Radial engines |
| B. | Side valve engines |
| C. | Overhead valve engines |
| D. | Stationary engines |
| E. | All of the above |
| Answer» D. Stationary engines | |
| 55. |
For initially dry and saturated steam flowing through a nozzle the volue of critical pressure ratio is given by |
| A. | 0.577 |
| B. | 1 |
| C. | 0.528 |
| D. | 0.546 |
| E. | 0.75 |
| Answer» B. 1 | |
| 56. |
Of the calorific value ranges given below which one is generally for coal? |
| A. | 2500 - 4000 kcal/kg |
| B. | 1000 - 2500 kcal/kg |
| C. | 4000 - 7000 kcal/kg |
| D. | 8000 - 12000 kcal/kg |
| E. | 100 - 1000 kcal/kg |
| Answer» D. 8000 - 12000 kcal/kg | |
| 57. |
The function of a piston rins in an internal combustion engine is |
| A. | To prevent lubricating oil from entering the combustion space |
| B. | To prevent leakage of combustion chamber products |
| C. | To transfer heat from piston to cylinder walls |
| D. | All of the above |
| E. | None of the above |
| Answer» E. None of the above | |
| 58. |
In naturally aspirated engine the pressure inside cylinder at the end of suction stroke is |
| A. | Less than atmospheric |
| B. | Same as atmospheric |
| C. | More than atmospheric |
| D. | Depends on atmospheric conditions |
| E. | None of the above |
| Answer» B. Same as atmospheric | |
| 59. |
Zeroth law of thermodynamics states that |
| A. | Two systems are always in equilibrium |
| B. | If two systems are in equilibrium the third system will also be in equilibrium |
| C. | If two systems are in thermal equilibrium with a third system, then they are in equilibrium with each other |
| D. | Two systems not in equilibrium with a third system are also not in equilibrium with each other |
| E. | None of the above |
| Answer» D. Two systems not in equilibrium with a third system are also not in equilibrium with each other | |
| 60. |
If performance of SI engines of different manufacture having different capacities, sizes and systems are to be compared the common parameter would be |
| A. | Engine cylinder diameter |
| B. | B.H.P. |
| C. | Weight of engine |
| D. | Speed |
| E. | Mean effective pressure |
| Answer» F. | |
| 61. |
If a heat engine given an output of 3.5 kW and input is 10000 Joules per second, the thermal efficiency of the engine will be |
| A. | 66?% |
| B. | 35% |
| C. | 30% |
| D. | 65% |
| E. | 55% |
| Answer» C. 30% | |
| 62. |
In a jet propulsion unit the products of combustion after passing through the gas turbine are discharged into |
| A. | Recycled back to compressor |
| B. | Atmosphere |
| C. | Compressor |
| D. | Vacuum |
| E. | Discharge nozzle |
| Answer» F. | |
| 63. |
For reciprocating air compressor the law of compression desired is isothermal and that may be possible by |
| A. | Very high speeds |
| B. | very low speeds |
| C. | any speed as speed does not affect the compression law |
| D. | None of the above |
| E. | Carbon dioxide |
| Answer» C. any speed as speed does not affect the compression law | |
| 64. |
In a SI engine the advancing of spark timing will |
| A. | Increase knocking tendency |
| B. | Reduce knocking tendency |
| C. | Not have any effect |
| D. | Depends on intensity of spark only |
| E. | None of the above |
| Answer» B. Reduce knocking tendency | |
| 65. |
The Clapeyron equation is applicable for |
| A. | System in equilibrium |
| B. | Change of state |
| C. | Change of state when two phases are in equilibrium |
| D. | Change of state when water and water vapours are involved |
| E. | None of the above |
| Answer» D. Change of state when water and water vapours are involved | |
| 66. |
A D-slide valve is used in |
| A. | Two stroke engines |
| B. | Diesel engines |
| C. | Petrol engines |
| D. | Steam engines |
| E. | Double acting engines |
| Answer» E. Double acting engines | |
| 67. |
In a surface condenser near to the air pump suction the vacuum is 500 mm of mercury with 730 mm of mercury height in a barometer. The pressure near the air pump suction would be |
| A. | 0.69 kg/sq-cm |
| B. | 1.213 kg/sq-cm |
| C. | 0.313 kg/sq-cm |
| D. | 0.687 kg/sq-cm |
| E. | 1230 mm Hg |
| Answer» B. 1.213 kg/sq-cm | |
| 68. |
The instrument used for the measurement of area of p-v diagram is known as |
| A. | Digitometer |
| B. | Clinometer |
| C. | Planimeter |
| D. | Areameter |
| E. | Graphometer |
| Answer» D. Areameter | |
| 69. |
The use of Wilson's line for flow calculation is associated with |
| A. | Impulse turbines |
| B. | Reaction turbines |
| C. | Diesel engines |
| D. | Steam-nozzles |
| E. | Gas turbines |
| Answer» E. Gas turbines | |
| 70. |
The lowest temperature upto which a mercury thermometer can be used is |
| A. | ? 39?C |
| B. | ? 260?C |
| C. | ? 173?C |
| D. | ? 10?C |
| E. | 0?C |
| Answer» B. ? 260?C | |
| 71. |
Intake air filters are provided on air compressor for |
| A. | Removing dirt and dust from suction air |
| B. | Reducing temperature of suction air |
| C. | Reducing pressure of suction pressure |
| D. | Removing impurities of air |
| E. | None of the above |
| Answer» B. Reducing temperature of suction air | |
| 72. |
The term scavanging is generally associated with |
| A. | High speed engines |
| B. | Air cooled engines |
| C. | Multi-cylinder engines |
| D. | Two stroke engines |
| E. | Vertical engines |
| Answer» E. Vertical engines | |
| 73. |
The frictional horse power of a well adjusted petrol engine should be nearly |
| A. | 50% |
| B. | 40% |
| C. | 25% |
| D. | Carbon dioxide |
| E. | 10% |
| Answer» F. | |
| 74. |
If in a compression ignition engine the noise level is to be reduced, the design features which will not be affected are |
| A. | Combustion system |
| B. | Exhaust muffling |
| C. | Intake muffling |
| D. | Fuel injection equipment |
| E. | None of the above |
| Answer» E. None of the above | |
| 75. |
A rich mixture will have an air-fuel ratio |
| A. | Less than chemically correct |
| B. | More than chemically correct |
| C. | Chemically correct |
| D. | Any of the above |
| E. | None of the above |
| Answer» B. More than chemically correct | |
| 76. |
Solubility of a gas in a liquid at small concentration is represented in |
| A. | Henry's law |
| B. | Clausius Clapeyron equation |
| C. | Raoult's law |
| D. | Dalton's law |
| E. | None of the above |
| Answer» B. Clausius Clapeyron equation | |
| 77. |
The blades of a turbine are made of |
| A. | High speed steel |
| B. | Cast iron |
| C. | Alloy steel |
| D. | Nickel alloy |
| E. | Stainless steel |
| Answer» E. Stainless steel | |
| 78. |
For dry saturated steam the value of adiabatic index n is taken as |
| A. | 1.135 |
| B. | 1.41 |
| C. | 1.35 |
| D. | 25 to 30 |
| E. | 1.68 |
| Answer» B. 1.41 | |
| 79. |
Ignition quality of diesel fuel is expressed by |
| A. | Octane number |
| B. | Cetane number |
| C. | Carbon percentage |
| D. | Calorific value |
| E. | None of the above |
| Answer» C. Carbon percentage | |
| 80. |
Rateau turbine is a |
| A. | Velocity compounded impulse turbine |
| B. | Pressure compounded reaction turbine |
| C. | Velocity compounded reaction turibine |
| D. | Pressure compounded impulse turbine |
| E. | Pressure-velocity compounded turbine |
| Answer» E. Pressure-velocity compounded turbine | |
| 81. |
In a lead cell battery the voltage per cell is |
| A. | 6 volts |
| B. | 1 volt |
| C. | 1.5 volt |
| D. | 2 volts |
| E. | 1.1 volt |
| Answer» E. 1.1 volt | |
| 82. |
In a petrol engine the mixture strength for maximum power is |
| A. | 1 ; 5 |
| B. | Carbon dioxide |
| C. | 1 ; 30 |
| D. | 1 ; 23 |
| E. | 1 ; 13 |
| Answer» F. | |
| 83. |
Centrifugal blowers can supply |
| A. | Large volumes of air at low pressures |
| B. | Large volumes of air at high pressures |
| C. | Small volumes of air at high pressures |
| D. | Small volumes of air at low pressures |
| E. | None of the above |
| Answer» B. Large volumes of air at high pressures | |
| 84. |
The engine provided on scooters is generally |
| A. | Four stroke, air cooled |
| B. | Four cylinder, air cooled |
| C. | Two stroke, double acting |
| D. | Two stroke, air cooled |
| E. | Four stroke, water cooled |
| Answer» E. Four stroke, water cooled | |
| 85. |
The sulphur content in diesel oil should not exceed |
| A. | 15% |
| B. | 5% |
| C. | 12% |
| D. | 1% |
| E. | 10% |
| Answer» E. 10% | |
| 86. |
Total sulphur content in a diesel fuel oil must not exceed |
| A. | 0.10% |
| B. | 0.01% |
| C. | 0.05% |
| D. | 0.50% |
| E. | 1% |
| Answer» E. 1% | |
| 87. |
The level of oil in engine cylinder should be checked when the engine is |
| A. | Not running |
| B. | Running |
| C. | During starting |
| D. | During cranking |
| E. | None of the above |
| Answer» B. Running | |
| 88. |
Water and sediments in a diesel fuel oil must not exceed. |
| A. | 0.50% |
| B. | 0.01% |
| C. | 1% |
| D. | 0.10% |
| E. | 0.05% |
| Answer» F. | |
| 89. |
The ash content in diesel oil should not exceed |
| A. | 0.10% |
| B. | 0.50% |
| C. | 5% |
| D. | 0.01% |
| E. | 1% |
| Answer» E. 1% | |
| 90. |
Which one of the following factors will not assist in getting high power output from a compression ignition engine |
| A. | High compression ratio |
| B. | Fine atomisation of fuel |
| C. | High charge density |
| D. | Large quantity of excess air |
| E. | None of the above |
| Answer» E. None of the above | |
| 91. |
Motoring test on I.C. engines is conducted to measure |
| A. | I.H.P. |
| B. | B.H.P. |
| C. | Pumping horse power |
| D. | Friction horse power |
| E. | None of the above |
| Answer» E. None of the above | |
| 92. |
Which of the following is an accessory for a boiler? |
| A. | Stop valve |
| B. | Feed check valve |
| C. | Safety valve |
| D. | Feed pump |
| E. | Blow off cock |
| Answer» E. Blow off cock | |
| 93. |
Ignition accelerators are often used for |
| A. | Diesel engine fuels |
| B. | Petrol engine fuels |
| C. | Gas turbine fuels |
| D. | Gas generators |
| E. | All of the above |
| Answer» C. Gas turbine fuels | |
| 94. |
Direction of feed water is done because |
| A. | It reduces weight of water to be handled |
| B. | It reduced priming difficulties in feed pumps |
| C. | It reduces corrosion caused by oxygen present in air |
| D. | It reduces amount of heat required to convert water into steam |
| E. | None of the above |
| Answer» D. It reduces amount of heat required to convert water into steam | |
| 95. |
The molecules move in a solid |
| A. | At random |
| B. | Back and forth like tiny pendulum |
| C. | In irregular motion |
| D. | In circular motion |
| E. | None of above |
| Answer» C. In irregular motion | |
| 96. |
A closed vessel contains air at 1.2 ata and 57?C. The pressure of air in the vessel if the contents of the vessel are cooled to 37?C would be |
| A. | 1.2 ata |
| B. | 1.127 ata |
| C. | 2.327 ata |
| D. | 0.563 ata |
| E. | 0.073 ata |
| Answer» C. 2.327 ata | |
| 97. |
Motor cycle not using deflector type piston usually utilise |
| A. | Reverse flow scavanging |
| B. | Ideal scavanging |
| C. | Uniflow scavanging |
| D. | Natural scavanging |
| E. | Loop scavanging |
| Answer» B. Ideal scavanging | |
| 98. |
A wankel engine is |
| A. | Rotory engine |
| B. | Turbine engine |
| C. | Jet engine |
| D. | Reciprocating engine |
| E. | Hybrid engine |
| Answer» B. Turbine engine | |
| 99. |
An Orsat's apparatus is used for |
| A. | None of above |
| B. | Gravimetric analysis of the flue gases |
| C. | Volumetric analysis of the flue gas |
| D. | Smoke density analysis of the flue gases |
| E. | All of above |
| Answer» D. Smoke density analysis of the flue gases | |
| 100. |
The phenomenon of hunting is associated with |
| A. | Governors |
| B. | Gears |
| C. | Cloth mechanism |
| D. | Carburetors |
| E. | Tappet valves |
| Answer» B. Gears | |