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.
| 101. |
Paraffins in petrol have the general formula |
| A. | Cn Hn |
| B. | Cn H2n + 2 |
| C. | Cn H2n - 4 |
| D. | Cn H2n |
| E. | Cn H2n - 2 |
| Answer» C. Cn H2n - 4 | |
| 102. |
Latent heat is |
| A. | Heat required to change the state or condition under which the substance exists |
| B. | Heat that does not follow first law of thermodynamics |
| C. | Heat required to change the state of substance from liquid state to solid state |
| D. | Heat required to change the substance from solid to gaseous state |
| E. | Heat cannot be detected |
| Answer» B. Heat that does not follow first law of thermodynamics | |
| 103. |
The term regeneration is closely associated with |
| A. | Steam engines |
| B. | Steam turbines |
| C. | Diesel engines |
| D. | Gas engines |
| E. | Wankel engines |
| Answer» C. Diesel engines | |
| 104. |
The turbidity in boiler feed water causes |
| A. | Sludge |
| B. | Scale |
| C. | Corrosion |
| D. | Embrittlement |
| E. | None of the above |
| Answer» B. Scale | |
| 105. |
Within the boiler the temperature of steam is highest in |
| A. | Water drum |
| B. | water tubes |
| C. | Superheater outlet |
| D. | Water walls |
| E. | Superheater inlet |
| Answer» D. Water walls | |
| 106. |
The dryness fraction of steam within a turbine is usually not allowed to fali below |
| A. | Unity |
| B. | 0.45 |
| C. | 0.8 |
| D. | 0.9 |
| E. | 0.99 |
| Answer» E. 0.99 | |
| 107. |
Engines are supercharged |
| A. | To increase engine durability |
| B. | To increase specific power output |
| C. | To increase air-fuel ratio |
| D. | To improve heat transfer |
| E. | To reduce combustion temperature |
| Answer» C. To increase air-fuel ratio | |
| 108. |
Steam leaves the steam nozzle at |
| A. | Low pressure and low velocity |
| B. | Low pressure and high velocity |
| C. | High pressure and low velocity |
| D. | High pressure and high velocity |
| E. | None of the above |
| Answer» C. High pressure and low velocity | |
| 109. |
Injector is used to |
| A. | Inject wet steam into superheater |
| B. | Inject steam into steam engine cylinder |
| C. | Inject secondary air in boiler furnace |
| D. | Inject water boiler |
| E. | Inject exhaust gases into chimney |
| Answer» E. Inject exhaust gases into chimney | |
| 110. |
In all a four stroke four cylinder engine will have how many valves? |
| A. | 8 |
| B. | 16 |
| C. | none |
| D. | 4 |
| E. | Carbon dioxide |
| Answer» B. 16 | |
| 111. |
Steam consumption per kWh of electricity generated in a modern power plant is of the order of |
| A. | 10 -12 kgs |
| B. | 5 - 7 kgs |
| C. | 8 - 10 kgs |
| D. | 2 - 4 kgs |
| E. | 1 - 2 kgs |
| Answer» C. 8 - 10 kgs | |
| 112. |
Motor cycles generally have |
| A. | Evaporative cooling system |
| B. | Natural cooling engines |
| C. | Ice cooled engines |
| D. | Natural cooling engines |
| E. | Air cooled engines |
| Answer» F. | |
| 113. |
If an air cooled compressor gets over-heated during operation, the probable cause cannot be |
| A. | Direction of rotation wrong |
| B. | Valve strips broken |
| C. | Leadage in intercooler |
| D. | Insufficient lubricating oil |
| E. | Intake fliter clogged |
| Answer» D. Insufficient lubricating oil | |
| 114. |
A gas turbine power plant suits as |
| A. | Peak load plant |
| B. | Casual run plant |
| C. | Base load plant |
| D. | All of the above |
| E. | None of the above |
| Answer» B. Casual run plant | |
| 115. |
A fan is being operated in an environment for which information is available. Now if the fan speed is doubled, how will the static pressure vary |
| A. | Eight times |
| B. | No change |
| C. | Sixteen times |
| D. | Doubled |
| E. | Four times |
| Answer» F. | |
| 116. |
A barn is a |
| A. | Unit of momentum |
| B. | Unit of time |
| C. | Unit of area |
| D. | Unit of length |
| E. | Unit of mass |
| Answer» D. Unit of length | |
| 117. |
In power station practice 'spinning reserve' is |
| A. | Reserve generating capacity that is in operation but in service |
| B. | Reserve generating capacity that is connected to bus and ready to take load |
| C. | Reserve generating capacity that is available for service but not in operation |
| D. | Capacity of the part of plant that remains under maintenance |
| E. | None of the above |
| Answer» C. Reserve generating capacity that is available for service but not in operation | |
| 118. |
Which of the following is not a property of carbondioxide? |
| A. | Non-toxic |
| B. | Non-inflammable |
| C. | Colourless |
| D. | Pungent odour |
| E. | None of the above |
| Answer» E. None of the above | |
| 119. |
A perfect heat engine works on the Carnot cycle between 1000?C and 200?C. The efficiency of the engine will be |
| A. | 42.80% |
| B. | 60% |
| C. | 62.80% |
| D. | 80% |
| E. | 37.20% |
| Answer» D. 80% | |
| 120. |
A plant costing Rs. 80,000 has a useful life of 12 years. The amount that should be saved annually to replace the equipment at the end of useful life with salvage value of Rs. 8,000 should be |
| A. | Rs. 15000 |
| B. | Rs. 8000 |
| C. | Rs. 6000 |
| D. | Rs. 5000 |
| E. | Rs. 10000 |
| Answer» D. Rs. 5000 | |
| 121. |
Ignition accelerators are used primarily to |
| A. | Reduce exhaust temperature |
| B. | Convert carbon monoxide into carbon dioxide |
| C. | Reduce combustion knock |
| D. | Cool the engine cylinder |
| E. | All of the above |
| Answer» D. Cool the engine cylinder | |
| 122. |
A 50 cfm compressor can |
| A. | Compress 50 cu feet per min of free air |
| B. | Compress 50 cu feet per min of standard air |
| C. | Deliver 50 cu feet of compressed air at delivery pressure |
| D. | Delivers 50 cu ft. per minute of compressed air |
| E. | None of the above |
| Answer» B. Compress 50 cu feet per min of standard air | |
| 123. |
In diesel engines, the accumulation of carbon in the cylinder increases |
| A. | Mechanical efficiency |
| B. | Volumetric efficiency |
| C. | Ignition delay period |
| D. | Effective compression ratio |
| E. | Clearance volume |
| Answer» E. Clearance volume | |
| 124. |
Which of the following is the internal loss of a turbine? |
| A. | None of above |
| B. | Blade friction loss |
| C. | Nozzle loss |
| D. | All of above |
| E. | Wheel friction loss |
| Answer» C. Nozzle loss | |
| 125. |
A heat exchanger that can remove fixed quantity of heat from a system is available where should it be installed for best economy |
| A. | Anywhere |
| B. | As intercooler |
| C. | After final stage compression |
| D. | Depends upon size of installation |
| E. | Prior to first stage compression |
| Answer» F. | |
| 126. |
A passout turbine generally operates on low pressure in the range |
| A. | 10 - 20 kg/cm2 |
| B. | 100 - 150 kg/cm2 |
| C. | 20 - 50 kg/cm2 |
| D. | 150 - 300 kg/cm2 |
| E. | 50 - 100 kg/cm2 |
| Answer» B. 100 - 150 kg/cm2 | |
| 127. |
In diesel engines thermal efficiency may be expected in the range |
| A. | 35 to 40 percent |
| B. | 10 - 15 percent |
| C. | 15 to 25 percent |
| D. | 50 percent |
| E. | 25 to 30 percent |
| Answer» B. 10 - 15 percent | |
| 128. |
Steam trap is a device that |
| A. | Allows passage of water but prevents the passage of steam |
| B. | Allows passage of air but prevents passage of steam |
| C. | Allows passage of the flue gases but prevents flow of steam |
| D. | None of the above |
| E. | Chain grate stokers |
| Answer» B. Allows passage of air but prevents passage of steam | |
| 129. |
Crankcase dilution is |
| A. | Dilution of fuel in crank case |
| B. | Dilution of lubricating oil in crankcase |
| C. | Dilution of mixture while passing through crankcase in two stroke engines |
| D. | Addition of water in crankcase |
| E. | None of the above |
| Answer» C. Dilution of mixture while passing through crankcase in two stroke engines | |
| 130. |
In reciprocating air compressor, the method of controlling the quantity of air delivered is done by |
| A. | Clearance Control |
| B. | Throttle Control |
| C. | Blow-off Control |
| D. | All of the above |
| E. | Carbon dioxide |
| Answer» E. Carbon dioxide | |
| 131. |
Temporary hardness of water is caused by |
| A. | Bicarbonates of calcium and magnesium |
| B. | Sulphates of calcium and magnesium |
| C. | Chlorides of calcium and magnesium |
| D. | Nitrates of calcium and magnesium |
| E. | None of the above |
| Answer» B. Sulphates of calcium and magnesium | |
| 132. |
A low pressure accumulator is generally used with which of the following turbine |
| A. | Mixed pressure turbine |
| B. | Back pressure turbine |
| C. | Impulse turbine |
| D. | Condensing turbine |
| E. | Reaction turbine |
| Answer» B. Back pressure turbine | |
| 133. |
If after some use the lower part, electrodes and beathing space of a spark plug are found coated by deposits of soot and carbon, the conclusion will be |
| A. | Spark plug is of proper heat rating |
| B. | Spark advance is incorrect |
| C. | Spark plug is short circuited |
| D. | Composition of mixture in the engine is correct |
| E. | Spark plug is of too high heat rating |
| Answer» F. | |
| 134. |
Ambassador car engine is |
| A. | F-type |
| B. | Overhead valve type |
| C. | Side valve type |
| D. | L-type |
| E. | Overhead inlet and side exhaust type |
| Answer» C. Side valve type | |
| 135. |
Which is not the cause for loss of heat in boiler due to incomplete combustion? |
| A. | Under cooling of furnace at low ratings |
| B. | Improper secting of boiler |
| C. | Insufficient air supply |
| D. | Boiler drum uninsulated |
| E. | Fuel bend in proof condition |
| Answer» E. Fuel bend in proof condition | |
| 136. |
Which of the following chemical acts as anti-freeze? |
| A. | Naphtha |
| B. | Glycol |
| C. | Ethyl alcohol |
| D. | Lead acetate |
| E. | n-heptane |
| Answer» C. Ethyl alcohol | |
| 137. |
A fan is being used under certain conditions. If the fan speed is doubled the power requirement will be |
| A. | 8 times |
| B. | 16 times |
| C. | Unchanged |
| D. | Double of the original |
| E. | Four times |
| Answer» B. 16 times | |
| 138. |
Which of the following engine can work on very lean mixture? |
| A. | Petrol engine |
| B. | Diesel engine |
| C. | Two stroke engine |
| D. | Wankel engine |
| E. | Four stroke engine |
| Answer» C. Two stroke engine | |
| 139. |
Crankcase explosion occurs in |
| A. | Four stroke SI engines |
| B. | Four stroke Cl engines |
| C. | Two stroke Cl engines |
| D. | Gas engines |
| E. | Two stroke SI engines |
| Answer» F. | |
| 140. |
A camshaft is not provided in case of |
| A. | Two stroke engines |
| B. | High speed engines |
| C. | Multicylinder engines |
| D. | ir cooled engines |
| E. | Vertical engines |
| Answer» B. High speed engines | |
| 141. |
Which one of the following statements is incorrect |
| A. | Combustion is the processes of heat liberation |
| B. | Combustion is a chemical reaction |
| C. | Combustion is rapid oxidation |
| D. | All of the above |
| E. | None of the above |
| Answer» E. None of the above | |
| 142. |
In jet engines the compression ratio |
| A. | Varies with altitude |
| B. | Varies with square of speed |
| C. | Varies as cube of speed |
| D. | Remains constant |
| E. | None of the above |
| Answer» C. Varies as cube of speed | |
| 143. |
If engines of different horse power, rpm, cylinder dimensions are to be compared for their performance, the parameter of comparison could be |
| A. | Mean effective pressure |
| B. | Specific speed |
| C. | Exhaust temperature |
| D. | Fuel consumption |
| E. | Unit speed |
| Answer» B. Specific speed | |
| 144. |
A 200 MW generator should be cooled by |
| A. | Nitrogen |
| B. | Hydrogen peroxide |
| C. | Hydrogen |
| D. | Water |
| E. | Air |
| Answer» D. Water | |
| 145. |
Corona is generally accompanied by a faint glow and |
| A. | Spark |
| B. | Sparking |
| C. | Heating of conductors |
| D. | Explosion |
| E. | Hissing noise |
| Answer» F. | |
| 146. |
The compression ratio in case of a gas turbine is of the order of |
| A. | 7 |
| B. | 12 |
| C. | 20 |
| D. | 5 |
| E. | 24 |
| Answer» B. 12 | |
| 147. |
A fuel of octane rating 85 matches the antiknock qualities of mixture consisting of |
| A. | 85% heptane + 15% octane |
| B. | 85% octane + 15% heptane |
| C. | 85% petrol + 15% diesel |
| D. | 85% benzene + 15% methyl alcohol |
| E. | 15% petrol + 85% diesel |
| Answer» C. 85% petrol + 15% diesel | |
| 148. |
In gas and petrol engines thermal efficiency may be expected in the range |
| A. | 50 percent |
| B. | 30 to 35 percent |
| C. | 10 - 15 percent |
| D. | 15 to 25 percent |
| E. | 60 percent |
| Answer» C. 10 - 15 percent | |
| 149. |
Thermodynamic processes are those |
| A. | Where a difference is observed in any macroscopic property of the system between different times or state |
| B. | Where a difference is observed in any microscopic property of the system between different times or state |
| C. | Which occurs in the direction of an intensive property or driving force contained within the system |
| D. | Which require an agency outside the system to force the process |
| E. | None of the above |
| Answer» B. Where a difference is observed in any microscopic property of the system between different times or state | |
| 150. |
Which of the following is not a part of diesel engine? |
| A. | Gudgeon pin |
| B. | Air filter |
| C. | Oil pump |
| D. | Condenser |
| E. | Lubricating oil filter |
| Answer» E. Lubricating oil filter | |