MCQOPTIONS
Saved Bookmarks
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.
| 101. |
Thermal efficiency of well maintained boiler will be of the order |
| A. | 0 % |
| B. | 0 % |
| C. | 5 % |
| D. | 0 % |
| Answer» E. | |
| 102. |
A throttle governed steam engine develops 15 kW with 280 kg per hour of steam and 35 kW with 520 kg per hour of steam. The steam consumption in kg per hour when developing 20 kW will be nearly |
| A. | 50 kg/h |
| B. | 10 kg/h |
| C. | 80 kg/h |
| D. | 40 kg/h |
| Answer» E. | |
| 103. |
The maximum heat loss is a boiler occurs due to |
| A. | oisture in fuel |
| B. | ry flue gases |
| C. | team formation |
| D. | nburnt carbon |
| Answer» C. team formation | |
| 104. |
The maximum steam pressure in a Locomotive boiler is limited to |
| A. | .18 MN/m² |
| B. | .8 MN/m² |
| C. | 8 MN/m² |
| D. | 80 MN/m² |
| Answer» C. 8 MN/m² | |
| 105. |
The efficiency of a boiler is defined as |
| A. | atio of heat actually used in producing steam to the heat liberated in the furnace |
| B. | atio of the mass of steam produced to the mass of total water supplied in a given time |
| C. | atio of the heat liberated in the furnace to the heat actually used in producing steam |
| D. | one of the above |
| Answer» B. atio of the mass of steam produced to the mass of total water supplied in a given time | |
| 106. |
All steam engines work on |
| A. | eroth law of thermodynamics |
| B. | irst law of thermodynamics |
| C. | econd law of thermodynamics |
| D. | one of these |
| Answer» D. one of these | |
| 107. |
An economiser is generally placed between |
| A. | ast superheater or reheater and air preheater |
| B. | nduced draft fan and forced draft fan |
| C. | ir preheater and chimney |
| D. | one of the above |
| Answer» B. nduced draft fan and forced draft fan | |
| 108. |
Which of the following substance will have same percentage in both proximate and ultimate analysis? |
| A. | sh |
| B. | olatile matter |
| C. | oisture |
| D. | ydrogen |
| Answer» B. olatile matter | |
| 109. |
The impulse turbine rotor efficiency will have a maximum value of 0.5 cos 2α, where α is the nozzle exit flow angle, if the |
| A. | lades are equiangular |
| B. | lade velocity coefficient is unity |
| C. | lades are equiangular and frictionless |
| D. | lade solidity is 0.65 |
| Answer» D. lade solidity is 0.65 | |
| 110. |
The fire tubes in, a Coarran and Scottish marine boiler are |
| A. | orizontal |
| B. | ertical |
| C. | nclined |
| D. | oth horizontal and vertical |
| Answer» B. ertical | |
| 111. |
Locomotive boiler is of the following type |
| A. | ulti tubular |
| B. | orizontal |
| C. | nternally fired |
| D. | ll of the above |
| Answer» E. | |
| 112. |
The diameter of flue tube in a Cornish boiler is _________ that of the shell. |
| A. | ne-fourth |
| B. | ne-third |
| C. | wo-fifth |
| D. | hree-fifth |
| Answer» E. | |
| 113. |
The diameter of internal flue tubes of a Lancashire boiler is about _________ that of its shell. |
| A. | ne-fourth |
| B. | ne-third |
| C. | wo-fifth |
| D. | ne-half |
| Answer» D. ne-half | |
| 114. |
The cylindrical shell of a Lancashire boiler has diameter from |
| A. | to 2 m |
| B. | .25 to 2.25 m |
| C. | .5 to 2.5 m |
| D. | .75 to 2.75 m |
| Answer» E. | |
| 115. |
Lancashire boiler is of |
| A. | tationary < fire tube type |
| B. | orizontal type |
| C. | atural circulation type |
| D. | ll of the above |
| Answer» E. | |
| 116. |
100% efficiency of a thermal cycle cannot be achieved because of |
| A. | rictional losses |
| B. | t is not possible to achieve 0°K temperature |
| C. | eakage |
| D. | on availability of ideal substance |
| Answer» C. eakage | |
| 117. |
The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is |
| A. | ess |
| B. | ore |
| C. | qual |
| D. | ay be less or more depending on temperature |
| Answer» B. ore | |
| 118. |
In water wall furnace, the heat is transferred to the water walls by |
| A. | onvection |
| B. | adiation |
| C. | onduction |
| D. | adiation and conduction |
| Answer» C. onduction | |
| 119. |
In a throttling process |
| A. | team temperature remains constant |
| B. | team pressure remains constant |
| C. | team enthalpy remains constant |
| D. | team entropy remains constant |
| Answer» D. team entropy remains constant | |
| 120. |
Which of the following are boiler accessories? |
| A. | conomizer |
| B. | uperheater |
| C. | oth (A) and (B) |
| D. | one of these |
| Answer» D. one of these | |
| 121. |
In designing air preheaters, the important design consideration is that |
| A. | pproach temperature should be as low as possible |
| B. | andling and maintenance should be easier |
| C. | eat transfer area should be optimum |
| D. | tack gases should not be cooled to the dew point |
| Answer» E. | |
| 122. |
For the same length of stroke and speed of crankshaft, the piston speed for a double acting steam engine is _________ the piston speed of single acting steam engine. |
| A. | qual to |
| B. | wice |
| C. | hree times |
| D. | our times |
| Answer» C. hree times | |
| 123. |
Which of the following varieties of coals is mostly used in steam boilers? |
| A. | on-coking bituminous coal |
| B. | rown coal |
| C. | eat |
| D. | one of the above |
| Answer» E. | |
| 124. |
During storage, the heating value of coal |
| A. | ncreases |
| B. | ecreases |
| C. | emain constant |
| D. | ay increase or decrease depending upon the method of storage |
| Answer» C. emain constant | |
| 125. |
On Mollier chart, free expansion, or throttling process from high pressure to atmosphere is represented by |
| A. | orizontal straight line |
| B. | ertical straight line |
| C. | traight inclined line |
| D. | urved line |
| Answer» B. ertical straight line | |
| 126. |
The indicated thermal efficiency is defined as the |
| A. | atio of thermal efficiency to the Rankine efficiency |
| B. | atio of brake power to the indicated power |
| C. | atio of heat equivalent to indicated power to the energy supplied in steam |
| D. | roduct of thermal efficiency and Rankine efficiency |
| Answer» D. roduct of thermal efficiency and Rankine efficiency | |
| 127. |
Boiler H.P. is defined as the |
| A. | team evaporation rate per kg of fuel fired |
| B. | ork done in evaporating 1 kg of steam per hour from and at 100°C into dry saturated steam |
| C. | he evaporation of 15.65 kg of water per hour from and at 100°C into dry saturated steam |
| D. | ork done by 1 kg of steam at saturation condition |
| Answer» D. ork done by 1 kg of steam at saturation condition | |
| 128. |
When the inlet pressure of steam is equal to the exit pressure, then |
| A. | here is a pressure drop in the nozzle |
| B. | luid flows through the nozzle |
| C. | ressure drops and fluid flows through the nozzle |
| D. | here is no pressure drop and fluid does not flow through the nozzle |
| Answer» E. | |
| 129. |
Carbonization of coal is the process of |
| A. | ulverizing coal in inert atmosphere |
| B. | eating wood in a limited supply of air at temperatures below 300°C |
| C. | trongly heating coal continuously for about 48 hours in the absence of air in a closed vessel |
| D. | inding the pulverized coal into briquettes |
| Answer» D. inding the pulverized coal into briquettes | |
| 130. |
At very low temperature, the melting and boiling temperatures become equal. This temperature is |
| A. | 73°K |
| B. | 73.16°K |
| C. | 03°K |
| D. | °K |
| Answer» C. 03°K | |
| 131. |
When the circulation of water, in a boiler, is by convection currents which are set up during the heating of water, then the boiler is known as |
| A. | nternally fired boiler |
| B. | xternally fired boiler |
| C. | atural circulation boiler |
| D. | orced circulation boiler |
| Answer» D. orced circulation boiler | |
| 132. |
An economiser in a boiler |
| A. | ncreases steam pressure |
| B. | ncreases steam flow |
| C. | ecreases fuel consumption |
| D. | ecreases steam pressure |
| Answer» D. ecreases steam pressure | |
| 133. |
Orsat meter is used for |
| A. | ravimetric analysis of the flue gases |
| B. | olumetric analysis of the flue gases |
| C. | ass flow of the flue gases |
| D. | easuring smoke density of flue gases |
| Answer» C. ass flow of the flue gases | |
| 134. |
The basic job of feed water treatment in boilers is to overcome the problem of |
| A. | orrosion |
| B. | cale |
| C. | arryover |
| D. | ll of the above |
| Answer» E. | |
| 135. |
The fusible plug in small boilers is located |
| A. | n the drum |
| B. | n the fire tubes |
| C. | bove steam dome |
| D. | ver the combustion chamber |
| Answer» E. | |
| 136. |
The length of Cornish boiler varies from |
| A. | to 4.5 m |
| B. | to 5 m |
| C. | to 7.5 m |
| D. | to 9 m |
| Answer» D. to 9 m | |
| 137. |
The diameter of superheated tubes in a locomotive boiler is |
| A. | 3 mm |
| B. | 1 mm |
| C. | 30 mm |
| D. | 30 mm |
| Answer» D. 30 mm | |
| 138. |
The amount of water evaporated from feed water at _________ into dry and saturated steam at 100° C at normal atmospheric pressure is called equivalent evaporation from and at 100° C. |
| A. | °C |
| B. | 0°C |
| C. | 0°C |
| D. | 00°C |
| Answer» E. | |
| 139. |
When the cross-section of a nozzle __________ continuously from entrance to exit, it is called a convergent nozzle. |
| A. | ncreases |
| B. | ecreases |
| C. | emain same |
| D. | one of these |
| Answer» C. emain same | |
| 140. |
Pick up the wrong statement about critical condition of steam |
| A. | atent heat is zero |
| B. | iquid directly becomes steam |
| C. | pecific volume of steam and liquid is same |
| D. | his is the maximum pressure limit |
| Answer» E. | |
| 141. |
The Locomotive boiler has |
| A. | 37 fire tubes and 44 superheated tubes |
| B. | 47 fire tubes and 34 superheated tubes |
| C. | 57 fire tubes and 24 superheated tubes |
| D. | 67 fire tubes and 14 superheated tubes |
| Answer» D. 67 fire tubes and 14 superheated tubes | |
| 142. |
The shell diameter and length of locomotive boiler are |
| A. | .5 m, 4 m |
| B. | .5 m, 6 m |
| C. | m, 4 m |
| D. | m, 4 m |
| Answer» B. .5 m, 6 m | |
| 143. |
The diameters of fire tubes and superheater tubes in locomotive boiler are |
| A. | 7.5 mm, 130 mm |
| B. | 2.5 mm, 180 mm |
| C. | 5.5 mm, 210 mm |
| D. | 4.5 mm, 65 mm |
| Answer» B. 2.5 mm, 180 mm | |
| 144. |
Which is not the correct statement about moisture in coal? |
| A. | nherent moisture and surface moisture are different things |
| B. | n some coals moisture may be present up to 40% |
| C. | ome moisture in coal helps in better burning which is not possible with completely dry coal |
| D. | t increases thermal efficiency |
| Answer» E. | |
| 145. |
The ratio of heat actually used in producing the steam to the heat liberated in the furnace, is known as |
| A. | quivalent evaporation |
| B. | actor of evaporation |
| C. | oiler efficiency |
| D. | ower of a boiler |
| Answer» D. ower of a boiler | |
| 146. |
The balanced draft furnace is one using |
| A. | nduced draft fan and chimney |
| B. | nduced draft fan and forced draft fan |
| C. | orced draft fan and chimney |
| D. | ny one of the above |
| Answer» C. orced draft fan and chimney | |
| 147. |
O₂ content in atmospheric air on weight basis is |
| A. | 1 % |
| B. | 3 % |
| C. | 0 % |
| D. | 0 % |
| Answer» C. 0 % | |
| 148. |
O₂ content in atmospheric air on volume basis is |
| A. | 1 % |
| B. | 3 % |
| C. | 0 % |
| D. | 0 % |
| Answer» B. 3 % | |
| 149. |
The state of vapor under saturation condition is described by |
| A. | ressure alone |
| B. | emperature alone |
| C. | ressure and temperature |
| D. | ressure and dryness fraction |
| Answer» E. | |
| 150. |
Sulphur in coal results in |
| A. | orroding air heaters |
| B. | pontaneous combustion during coal storage |
| C. | acilitating ash precipitation |
| D. | ll of the above |
| Answer» E. | |