MCQOPTIONS
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MCQOPTIONS
This section includes 760 Mcqs, each offering curated multiple-choice questions to sharpen your Mechanical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
The shell of the Cochran boiler is made hemispherical |
| A. | o give maximum space and strength |
| B. | o withstand the pressure of steam inside the boiler |
| C. | oth (A) and (B) |
| D. | one of the above |
| Answer» D. one of the above | |
| 52. |
The critical pressure ratio (p₂/p₁) is given by |
| A. | p₂/p₁) = [2/(n - 1)] n/(n + 1) |
| B. | p₂/p₁) = [2/(n + 1)] n/(n-1) |
| C. | p₂/p₁) = [(n - 1)/2] n + (1/n) |
| D. | p₂/p₁) = [(n + 1)/2] n - (1/n) |
| Answer» C. p₂/p₁) = [(n - 1)/2] n + (1/n) | |
| 53. |
Which of the following is correct? (Where pa = Actual mean effective pressure, pm = Theoretical mean effective pressure, and K = Diagram factor) |
| A. | a = pm/K |
| B. | a = pm × K |
| C. | a = K/pm |
| D. | a = pm + K |
| Answer» C. a = K/pm | |
| 54. |
The fire tubes in a Locomotive boiler has __________ diameter. |
| A. | .75 mm |
| B. | .47 mm |
| C. | .45 mm |
| D. | 7.5 mm |
| Answer» E. | |
| 55. |
In regenerative air preheaters, the heat is transferred |
| A. | rom a metal wall from one medium to another |
| B. | rom heating an intermediate material and then heating the air from this material |
| C. | y direct mixing |
| D. | eat is transferred by bleeding some gas from furnace |
| Answer» C. y direct mixing | |
| 56. |
In recuperative air preheaters, the heat is transferred |
| A. | rom a metal wall from one medium to another |
| B. | rom heating an intermediate material and then heating the air from this material |
| C. | y direct mixing |
| D. | eat is transferred by bleeding some gases from furnace |
| Answer» B. rom heating an intermediate material and then heating the air from this material | |
| 57. |
An air preheater |
| A. | ncreases evaporative capacity of the boiler |
| B. | ncreases the efficiency of the boiler |
| C. | nables low grade fuel to be burnt |
| D. | ll of the above |
| Answer» E. | |
| 58. |
Which of the following is required for a steam condensing plant? |
| A. | ondenser |
| B. | ondensate pump |
| C. | ir extraction pump |
| D. | ll of these |
| Answer» E. | |
| 59. |
An economiser _________ the steam raising capacity of a boiler. |
| A. | ncreases |
| B. | ecreases |
| C. | as no effect on |
| D. | one of these |
| Answer» B. ecreases | |
| 60. |
Cochran boiler is a |
| A. | orizontal fire tube boiler |
| B. | orizontal water tube boiler |
| C. | ertical water tube boiler |
| D. | ertical fire tube boiler |
| Answer» E. | |
| 61. |
The biggest size of thermal power unit operating in India is |
| A. | 0 MW |
| B. | 0 MW |
| C. | 00 MW |
| D. | 00 MW |
| Answer» E. | |
| 62. |
A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are |
| A. | upplied by same manufacturer loose and assembled at site |
| B. | upplied mounted on a single base |
| C. | urchased from several parties and packed together at site |
| D. | ackaged boiler does not exist |
| Answer» C. urchased from several parties and packed together at site | |
| 63. |
The condition of steam in boiler drum is always |
| A. | ry |
| B. | et |
| C. | aturated |
| D. | upersaturated |
| Answer» C. aturated | |
| 64. |
In a steam condenser, the partial pressure of steam and air are 0.06 bar and 0.007 bar respectively. The condenser pressure is |
| A. | .007 bar |
| B. | .053 bar |
| C. | .06 bar |
| D. | .067 bar |
| Answer» E. | |
| 65. |
If partial pressure of air and steam be ‘pa’ and ‘ps’ respectively in a condenser, then according to Dalton's law, the pressure in condenser is equal to |
| A. | s - pa |
| B. | a - ps |
| C. | a + ps |
| D. | one of these |
| Answer» D. one of these | |
| 66. |
For a Parson's reaction turbine, if α₁ and α₂ are fixed blade angles at inlet and exit respectively and β₁ and β₂ are the moving blade angles at entrance and exit respectively, then |
| A. | ₁ = α₂ and β₁ = β₂ |
| B. | ₁ = β₁ and α₂= β₂ |
| C. | ₁ < β₁ and α₂ > β₂ |
| D. | ₁ = β₂ and β₁ = α₂ |
| Answer» C. ₁ < β₁ and α₂ > β₂ | |
| 67. |
Pick up wrong statement about desired properties of a good fuel |
| A. | igh calorific value |
| B. | roduce minimum smoke and gases |
| C. | ase in storing |
| D. | igh ignition point |
| Answer» E. | |
| 68. |
The ratio of the work-done on the blades per kg of steam to the total energy supplied per stage per kg of steam is called |
| A. | lading efficiency |
| B. | ozzle efficiency |
| C. | tage efficiency |
| D. | echanical efficiency |
| Answer» D. echanical efficiency | |
| 69. |
For burning 1 kg of carbon to CO as per chemically correct combustion, amount of air required is |
| A. | kg |
| B. | /3 kg |
| C. | /3 kg |
| D. | kg |
| Answer» C. /3 kg | |
| 70. |
At critical point, i.e. p=225.65 kg/cm², the latent enthalpy of vaporisation is |
| A. | aximum |
| B. | inimum |
| C. | ero |
| D. | epends on temperature also |
| Answer» D. epends on temperature also | |
| 71. |
In fire tube boilers |
| A. | ater passes through the tubes which are surrounded by flames and hot gases |
| B. | he flames and hot gases pass through the tubes which are surrounded by water |
| C. | orced circulation takes place |
| D. | one of these |
| Answer» C. orced circulation takes place | |
| 72. |
Pick up the wrong statement about water tube boiler in comparison to fire tube boilers |
| A. | ormer occupies less space for same power |
| B. | ate of steam flow is more in former case |
| C. | ormer is used for high installed capacity |
| D. | hances of explosion are less in former case |
| Answer» E. | |
| 73. |
Which of the following is a fire tube boiler? |
| A. | ancashire boiler |
| B. | abcock and Wilcox boiler |
| C. | arrow boiler |
| D. | one of these |
| Answer» B. abcock and Wilcox boiler | |
| 74. |
Which is not correct statement about the function of furnace? |
| A. | o provide proper conditions for continuous complete combustion |
| B. | ix fuel with air and ignite |
| C. | eparate ash from coal |
| D. | aintain heat supply to prepare and ignite the incoming fuel |
| Answer» D. aintain heat supply to prepare and ignite the incoming fuel | |
| 75. |
Hard coke is used in |
| A. | ement industry |
| B. | hermal power plant |
| C. | last furnace |
| D. | omestic use |
| Answer» D. omestic use | |
| 76. |
Degree of reaction is defined as the ratio of |
| A. | eat drop in fixed blades to the heat drop in moving blades |
| B. | eat drop in moving blades to the heat drop in fixed blades |
| C. | eat drop in moving blades to the heat drop in fixed blades plus heat drop in moving blades |
| D. | eat drop in fixed blades plus heat drop in moving blades to the heat drop in moving blades |
| Answer» D. eat drop in fixed blades plus heat drop in moving blades to the heat drop in moving blades | |
| 77. |
Which of the following boilers is best suited to meet fluctuating demands? |
| A. | abcock and Wilcox |
| B. | ocomotive |
| C. | ancashire |
| D. | ochran |
| Answer» C. ancashire | |
| 78. |
The diameter of fire tube of Cornish boiler compared to its shell is |
| A. | ne half |
| B. | ne third |
| C. | ne fourth |
| D. | ne fifth |
| Answer» B. ne third | |
| 79. |
The diameter of internal flue tubes in a Lancashire boiler compared to its shell is |
| A. | ne-half |
| B. | ne-third |
| C. | wo-fourth |
| D. | wo-fifth |
| Answer» E. | |
| 80. |
Locomotive type' boiler is |
| A. | orizontal multi-tubular water tube boiler |
| B. | ater wall enclosed furnace type |
| C. | ertical tubular fire tube type |
| D. | orizontal multi-tubular fire tube type |
| Answer» E. | |
| 81. |
For the same diameter and thickness of tube, a water tube boiler compared to a fire tube boiler has |
| A. | ore heating surface |
| B. | ess heating surface |
| C. | qual heating surface |
| D. | eating surface depends on other parameters |
| Answer» B. ess heating surface | |
| 82. |
There is always some steam left in the clearance space from the previous stroke. This steam left in the clearance space is called |
| A. | et steam |
| B. | aturated steam |
| C. | uperheated steam |
| D. | ushion steam |
| Answer» E. | |
| 83. |
Relative percentage of heat absorbed through the heat transfer of(i) Furnace water wall(ii) Boiler tank(iii) Superheater(iv) Economizer(v) Air-heater of a typical boiler of 200 MW capacity would be of the order of |
| A. | 8 : 20 : 15 : 7 : 10 |
| B. | 0 : 7 : 15 : 20 : 48 |
| C. | 0 : 48 : 7 : 15 : 10 |
| D. | : 15 : 20 : 10 : 48 |
| Answer» B. 0 : 7 : 15 : 20 : 48 | |
| 84. |
The clearance in the engine cylinder |
| A. | ncreases the mean effective pressure |
| B. | ncreases the workdone |
| C. | ecreases the efficiency of the engine |
| D. | ll of these |
| Answer» E. | |
| 85. |
For maximum discharge through a chimney, the condition is that height of hot gas column producing the draught should be |
| A. | ne-half the height of chimney |
| B. | qual to the height of chimney |
| C. | wo times the height of chimney |
| D. | our times the height of chimney |
| Answer» C. wo times the height of chimney | |
| 86. |
Desecration of feed water is carried out because it reduces |
| A. | avitation of boiler feed pumps |
| B. | orrosion caused by oxygen |
| C. | eat transfer coefficient |
| D. | H value of water |
| Answer» C. eat transfer coefficient | |
| 87. |
The equivalent evaporation of a boiler is a measure to compare |
| A. | he given boiler with the model |
| B. | he two different boilers of the same make |
| C. | wo different makes of boilers operating under the same operating conditions |
| D. | ny type of boilers operating under any conditions |
| Answer» E. | |
| 88. |
The flow of steam is supersonic |
| A. | t the entrance to the nozzle |
| B. | t the throat of the nozzle |
| C. | n the convergent portion of the nozzle |
| D. | n the divergent portion of the nozzle |
| Answer» E. | |
| 89. |
If a steam sample is nearly in dry condition, then its dryness fraction can be most accurately determined by |
| A. | hrottling calorimeter |
| B. | eparating calorimeter |
| C. | ombined separating and throttling calorimeter |
| D. | ucket calorimeter |
| Answer» B. eparating calorimeter | |
| 90. |
For water, at pressures below atmospheric; |
| A. | elting point rises slightly and boiling point drops markedly |
| B. | elting point rises markedly and boiling point drops markedly |
| C. | elting point drops slightly and boiling point drops markedly |
| D. | elting point drops slightly and boiling point drops slightly |
| Answer» B. elting point rises markedly and boiling point drops markedly | |
| 91. |
The change in internal energy in steam engines equals to |
| A. | ork done during the Rankine cycle |
| B. | ork done during compression |
| C. | ork done during adiabatic expansion |
| D. | hange in enthalpy |
| Answer» B. ork done during compression | |
| 92. |
The maximum discharge through a chimney occurs when the height of chimney is |
| A. | nfinitely long |
| B. | round 200 meters |
| C. | qual to the height of the hot gas column producing draught |
| D. | utside temperature is very low |
| Answer» D. utside temperature is very low | |
| 93. |
The pressure velocity compounded impulse turbine allows a bigger pressure drop and hence __________ numbers of stages are required. |
| A. | ore |
| B. | ess |
| C. | qual |
| D. | one of these |
| Answer» C. qual | |
| 94. |
The draught produced by a steam jet issuing from a nozzle placed in the ash-pit under the fire grate of the furnace is called |
| A. | nduced steam jet draught |
| B. | himney draught |
| C. | orced steam jet draught |
| D. | one of these |
| Answer» D. one of these | |
| 95. |
Which is not correct statement about pulverized fuel firing? |
| A. | igh burning rate is possible |
| B. | eat release can be easily controlled |
| C. | uel burns economically |
| D. | t is the best technique for burning high ash content fuel having low fusion ash |
| Answer» E. | |
| 96. |
Stoichiometric quantity of air is the |
| A. | ir present in atmosphere at NTP conditions |
| B. | ir required for complete combustion of fuel with no excess air |
| C. | ir required for optimum combustion so as to have reasonable excess air |
| D. | ir required to convert CO into CO₂ |
| Answer» C. ir required for optimum combustion so as to have reasonable excess air | |
| 97. |
The function of injector used in small capacity boilers is to |
| A. | reate vacuum |
| B. | nject chemical solution in feed pump |
| C. | ump water, similar to boiler feed pump |
| D. | dd make up water in the system |
| Answer» D. dd make up water in the system | |
| 98. |
The efficiency of reaction turbine is maximum when (where α = Angle made by the absolute velocity ‘V’ at inlet) |
| A. | b = 0.5 V cosα |
| B. | b = V cos α |
| C. | b = 0.5 V² cosα |
| D. | b = V² cos α |
| Answer» C. b = 0.5 V² cosα | |
| 99. |
Pick up the correct statement as regards Cornish boiler and Lancashire boiler |
| A. | ornish is fire tube and Lancashire is water tube |
| B. | ornish is water tube and Lancashire is fire tube |
| C. | ornish has two fire tubes and Lancashire has one |
| D. | ancashire has two fire tubes and Cornish has one |
| Answer» E. | |
| 100. |
The amount of water evaporated in kg per kg of fuel burnt is called |
| A. | vaporative capacity of a boiler |
| B. | quivalent evaporation from and at 100° C |
| C. | oiler efficiency |
| D. | one of these |
| Answer» B. quivalent evaporation from and at 100° C | |