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.
| 401. |
*/*_Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of? |
| A. | Higher effectiveness of boiler |
| B. | High calorific value coal being burnt |
| C. | Fouling of heat transfer surfaces |
| D. | Raising of steam temperature |
| Answer» D. Raising of steam temperature | |
| 402. |
%_The shell diameter and length of locomotive boiler are_% |
| A. | 1.5 m, 4 m |
| B. | 1.5 m, 6 m |
| C. | 1 m, 4 m |
| D. | 2 m, 4 m |
| Answer» B. 1.5 m, 6 m | |
| 403. |
%_In an impulse turbine_% |
| A. | The steam is expanded in nozzles only and there is a pressure drop and heat drop |
| B. | The steam is expanded both in fixed and moving blades continuously |
| C. | The steam is expanded in moving blades only |
| D. | The pressure and temperature of steam remains constant |
| Answer» B. The steam is expanded both in fixed and moving blades continuously | |
| 404. |
%_The balanced draft furnace is one using_% |
| A. | Induced draft fan and chimney |
| B. | Induced draft fan and forced draft fan |
| C. | Forced draft fan and chimney |
| D. | Any one of the above |
| Answer» C. Forced draft fan and chimney | |
| 405. |
%_In an impulse turbine, steam expands_% |
| A. | Wholly in blades |
| B. | Wholly in nozzle |
| C. | Partly in the nozzle and partly in blades |
| D. | None of these |
| Answer» C. Partly in the nozzle and partly in blades | |
| 406. |
%_The forced circulation of water does not take place in_% |
| A. | LaMont boiler |
| B. | Lancashire boiler |
| C. | Velox boiler |
| D. | Benson boiler |
| Answer» C. Velox boiler | |
| 407. |
%_Which of the following statement is correct for steam turbines as compared to reciprocating steam engines?_% |
| A. | A steam turbine develops higher speeds |
| B. | The efficiency of steam turbine is higher |
| C. | The steam consumption is less |
| D. | All of these |
| Answer» E. | |
| 408. |
%_Clearance ratio is the ratio of_% |
| A. | Clearance volume to the swept volume |
| B. | Clearance volume to the volume at cut-off |
| C. | Volume at cut-off to the swept volume |
| D. | Swept volume to the clearance volume |
| Answer» B. Clearance volume to the volume at cut-off | |
| 409. |
%_The three "Ts" for good combustion are_% |
| A. | Temperature, time, and turbulence |
| B. | Total air, true fuel, and turbulence |
| C. | Thorough mixing, total air and temperature |
| D. | Total air, time, and temperature |
| Answer» B. Total air, true fuel, and turbulence | |
| 410. |
%_An air preheater_% |
| A. | Increases evaporative capacity of the boiler |
| B. | Increases the efficiency of the boiler |
| C. | Enables low grade fuel to be burnt |
| D. | All of the above |
| Answer» E. | |
| 411. |
%_100% efficiency of a thermal cycle cannot be achieved because of_% |
| A. | Frictional losses |
| B. | It is not possible to achieve 0°K temperature |
| C. | Leakage |
| D. | Non availability of ideal substance |
| Answer» C. Leakage | |
| 412. |
%_The diameter of flue tube in a Cornish boiler is _________ that of the shell._% |
| A. | One-fourth |
| B. | One-third |
| C. | Two-fifth |
| D. | Three-fifth |
| Answer» E. | |
| 413. |
%_The selection of type and size of a steam boiler depends upon_% |
| A. | The power required and working pressure |
| B. | The geographical position of the power house |
| C. | The fuel and water available |
| D. | All of the above |
| Answer» E. | |
| 414. |
%_The artificial draught is produced by_% |
| A. | Steam jet |
| B. | Centrifugal fan |
| C. | Chimney |
| D. | Both (A) and (B) |
| Answer» E. | |
| 415. |
%_A safety valve usually employed with stationary boilers is_% |
| A. | Lever safety valve |
| B. | Dead weight safety valve |
| C. | High steam and low water safety valve |
| D. | All of these |
| Answer» E. | |
| 416. |
%_Steam turbines are used for_% |
| A. | Large marine propulsion |
| B. | Electric power generation |
| C. | Direct drive of fans, compressors, pumps |
| D. | All of these |
| Answer» E. | |
| 417. |
%_Carbonization of coal is the process of_% |
| A. | Pulverizing coal in inert atmosphere |
| B. | Heating wood in a limited supply of air at temperatures below 300°C |
| C. | Strongly heating coal continuously for about 48 hours in the absence of air in a closed vessel |
| D. | Binding the pulverized coal into briquettes |
| Answer» D. Binding the pulverized coal into briquettes | |
| 418. |
%_The indicated thermal efficiency is defined as the_% |
| A. | Ratio of thermal efficiency to the Rankine efficiency |
| B. | Ratio of brake power to the indicated power |
| C. | Ratio of heat equivalent to indicated power to the energy supplied in steam |
| D. | Product of thermal efficiency and Rankine efficiency |
| Answer» D. Product of thermal efficiency and Rankine efficiency | |
| 419. |
%_When the circulation of water, in a boiler, is by a centrifugal pump, then the boiler is known as_% |
| A. | Internally fired boiler |
| B. | Externally fired boiler |
| C. | Natural circulation boiler |
| D. | Forced circulation boiler |
| Answer» E. | |
| 420. |
%_The diameter of Cornish boiler varies from_% |
| A. | 0.5 to 1 m |
| B. | 1 to 2 m |
| C. | 1.25 to 2.5 m |
| D. | 2 to 3 m |
| Answer» C. 1.25 to 2.5 m | |
| 421. |
%_The shell diameter of a Locomotive boiler is_% |
| A. | 1 m |
| B. | 1.5 m |
| C. | 2 m |
| D. | 2.5 m |
| Answer» C. 2 m | |
| 422. |
%_Parson's turbine is a_% |
| A. | Simple impulse turbine |
| B. | Simple reaction turbine |
| C. | Impulse-reaction turbine |
| D. | None of these |
| Answer» C. Impulse-reaction turbine | |
| 423. |
%_Stoichiometric quantity of air is the_% |
| A. | Air present in atmosphere at NTP conditions |
| B. | Air required for complete combustion of fuel with no excess air |
| C. | Air required for optimum combustion so as to have reasonable excess air |
| D. | Air required to convert CO into CO‚ÇÇ |
| Answer» C. Air required for optimum combustion so as to have reasonable excess air | |
| 424. |
%_An economiser is generally placed between_% |
| A. | Last superheater or reheater and air preheater |
| B. | Induced draft fan and forced draft fan |
| C. | Air preheater and chimney |
| D. | None of the above |
| Answer» B. Induced draft fan and forced draft fan | |
| 425. |
%_The fire tubes in, a Coarran and Scottish marine boiler are_% |
| A. | Horizontal |
| B. | Vertical |
| C. | Inclined |
| D. | Both horizontal and vertical |
| Answer» B. Vertical | |
| 426. |
%_The amount of water evaporated in kg per kg of fuel burnt is called_% |
| A. | Evaporative capacity of a boiler |
| B. | Equivalent evaporation from and at 100° C |
| C. | Boiler efficiency |
| D. | None of these |
| Answer» B. Equivalent evaporation from and at 100¬¨‚àû C | |
| 427. |
%_The maximum steam pressure in a Locomotive boiler is limited to_% |
| A. | 0.18 MN/m² |
| B. | 1.8 MN/m² |
| C. | 18 MN/m² |
| D. | 180 MN/m² |
| Answer» C. 18 MN/m¬¨‚⧠| |
| 428. |
_ Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of$? |
| A. | Higher effectiveness of boiler |
| B. | High calorific value coal being burnt |
| C. | Fouling of heat transfer surfaces |
| D. | Raising of steam temperature |
| Answer» D. Raising of steam temperature | |
| 429. |
_ While steam expands in turbines, theoretically the entropy$? |
| A. | Remains constant |
| B. | Increases |
| C. | Decreases |
| D. | Behaves unpredictably |
| Answer» B. Increases | |
| 430. |
_ The heat loss in a boiler takes place in the form of$? |
| A. | Heat carried away by flue gases |
| B. | Heat carried away by ash |
| C. | Moisture present in fuel and steam formed by combustion of hydrogen in fuel |
| D. | All of the above |
| Answer» E. | |
| 431. |
_ Heating of dry steam above saturation temperature is known as$? |
| A. | Enthalpy |
| B. | Superheating |
| C. | Super saturation |
| D. | Latent heat |
| Answer» C. Super saturation | |
| 432. |
_ Green coal, in order to be burnt, must be$? |
| A. | Heated sufficiently |
| B. | Burnt in excess air |
| C. | Heated to its ignition point |
| D. | Burnt as powder |
| Answer» D. Burnt as powder | |
| 433. |
_ The effect of super-saturation is that the$? |
| A. | Mass of the steam discharged increases |
| B. | Entropy and specific volume of the steam increases |
| C. | Exit velocity of steam reduces |
| D. | All of these |
| Answer» E. | |
| 434. |
_ The ratio of the clearance volume to the swept volume is called$? |
| A. | Cut-off ratio |
| B. | Expansion ratio |
| C. | Clearance ratio |
| D. | None of these |
| Answer» D. None of these | |
| 435. |
_ A packaged boiler is one in which various parts like firing equipment, fans, feed pumps and automatic controls are$? |
| A. | Supplied by same manufacturer loose and assembled at site |
| B. | Supplied mounted on a single base |
| C. | Purchased from several parties and packed together at site |
| D. | Packaged boiler does not exist |
| Answer» C. Purchased from several parties and packed together at site | |
| 436. |
_ An air preheater$? |
| A. | Increases evaporative capacity of the boiler |
| B. | Increases the efficiency of the boiler |
| C. | Enables low grade fuel to be burnt |
| D. | All of the above |
| Answer» E. | |
| 437. |
_ In recuperative air preheaters, the heat is transferred$? |
| A. | From a metal wall from one medium to another |
| B. | From heating an intermediate material and then heating the air from this material |
| C. | By direct mixing |
| D. | Heat is transferred by bleeding some gases from furnace |
| Answer» B. From heating an intermediate material and then heating the air from this material | |
| 438. |
_ The function of a piston in a steam engine is$? |
| A. | To guide motion of the piston rod and to prevent it from bending |
| B. | To transfer motion from the piston to the cross-head |
| C. | To convert heat energy of the steam into mechanical work id) to exhaust steam from the cylinder at proper moment |
| D. | None of these |
| Answer» D. None of these | |
| 439. |
_ Which of the following is correct? (Where pa = Actual mean effective pressure, pm = Theoretical mean effective pressure, and K = Diagram factor)$? |
| A. | pa = pm/K |
| B. | pa = pm √ó K |
| C. | pa = K/pm |
| D. | pa = pm + K |
| Answer» C. pa = K/pm | |
| 440. |
_ The supersaturated flow of steam through a nozzle as compared to a stable flow, the available heat drop$? |
| A. | Remains the same |
| B. | Increases |
| C. | Decreases |
| D. | Is unpredictable |
| Answer» D. Is unpredictable | |
| 441. |
_ The critical pressure at which latent heat of vaporisation is zero is$? |
| A. | 225.65 kgf/ cm² |
| B. | 273 kgf/ cm² |
| C. | 100 kgf/ cm² |
| D. | 1 kgf/ cm² |
| Answer» B. 273 kgf/ cm¬¨‚⧠| |
| 442. |
_ Tertiary air is the air used to$? |
| A. | Provide air around burners for obtaining optimum combustion |
| B. | Transport and dry the coal |
| C. | Cool the scanners |
| D. | Convert CO (formed in lower zone of furnace) into CO‚ÇÇ at higher zone |
| Answer» E. | |
| 443. |
_ In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p‚ÇÇ) will be$? |
| A. | 3.3 bar |
| B. | 5.46 bar |
| C. | 8.2 bar |
| D. | 9.9 bar |
| Answer» C. 8.2 bar | |
| 444. |
_ Thermal efficiency of a thermal power plant is of the order of$? |
| A. | 15 % |
| B. | 20 % |
| C. | 30 % |
| D. | 45 % |
| Answer» D. 45 % | |
| 445. |
_ Caking coals are those which$? |
| A. | Form lumps or masses of coke |
| B. | Burn freely |
| C. | Show little or no fusing action |
| D. | Burn completely |
| Answer» B. Burn freely | |
| 446. |
_ Willian’s line for the steam engine is a straight line relationship between the steam consumption per hour and$? |
| A. | Indicated power |
| B. | Brake power |
| C. | Efficiency |
| D. | Pressure of steam |
| Answer» B. Brake power | |
| 447. |
_ The missing quantity per stroke is equal to$? |
| A. | Cylinder feed indicated mass of steam |
| B. | Cylinder feed + indicated mass of steam |
| C. | Mass of cushion steam + indicated mass of steam |
| D. | Mass of cushion steam + cylinder feed |
| Answer» B. Cylinder feed + indicated mass of steam | |
| 448. |
_ Which of the following boiler works on a forced circulation of water?$? |
| A. | Lamont boiler |
| B. | Benson boiler |
| C. | Loeffler boiler |
| D. | All of these |
| Answer» E. | |
| 449. |
_ Vacuum for reciprocating steam engines compared to steam turbines is$? |
| A. | More |
| B. | Equal |
| C. | Less |
| D. | Could be more or less depending on the size of plant |
| Answer» D. Could be more or less depending on the size of plant | |
| 450. |
_ When the cross-section of a nozzle increases continuously from entrance to exit, it is called a$? |
| A. | Divergent nozzle |
| B. | Convergent nozzle |
| C. | Convergent-divergent nozzle |
| D. | None of these |
| Answer» B. Convergent nozzle | |