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.
| 501. |
__The numbers of fire tubes in a Cochran boiler are__ |
| A. | 75 |
| B. | 115 |
| C. | 165 |
| D. | 225 |
| Answer» D. 225 | |
| 502. |
__The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is__ |
| A. | Less |
| B. | More |
| C. | Equal |
| D. | May be less or more depending on temperature |
| Answer» B. More | |
| 503. |
__The diameter of internal flue tubes of a Lancashire boiler is about _________ that of its shell.__ |
| A. | One-fourth |
| B. | One-third |
| C. | Two-fifth |
| D. | One-half |
| Answer» D. One-half | |
| 504. |
__Which of the following are boiler accessories?__ |
| A. | Economizer |
| B. | Superheater |
| C. | Both (A) and (B) |
| D. | None of these |
| Answer» D. None of these | |
| 505. |
__The object of producing draught in a boiler is__ |
| A. | To provide an adequate supply of air for the fuel combustion |
| B. | To exhaust the gases of combustion from the combustion chamber |
| C. | To discharge the gases of combustion to the atmosphere through the chimney |
| D. | All of the above |
| Answer» E. | |
| 506. |
__The equivalent evaporation is defined as__ |
| A. | The ratio of heat actually used in producing the steam to the heat liberated in the furnace |
| B. | The amount of water evaporated or steam produced in kg per kg of fuel burnt |
| C. | The amount of water evaporated from and at 100°C into dry and saturated steam |
| D. | The evaporation of 15.653 kg of water per hour from and at 100°C |
| Answer» D. The evaporation of 15.653 kg of water per hour from and at 100¬¨‚àûC | |
| 507. |
__Which of the following varieties of coals is mostly used in steam boilers?__ |
| A. | Non-coking bituminous coal |
| B. | Brown coal |
| C. | Peat |
| D. | None of the above |
| Answer» E. | |
| 508. |
__At very low temperature, the melting and boiling temperatures become equal. This temperature is__ |
| A. | 373°K |
| B. | 273.16°K |
| C. | 303°K |
| D. | 0°K |
| Answer» C. 303¬¨‚àûK | |
| 509. |
__The relative efficiency is defined as the__ |
| A. | Ratio of thermal efficiency to 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» B. Ratio of brake power to the indicated power | |
| 510. |
_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$? |
| A. | Internally fired boiler |
| B. | Externally fired boiler |
| C. | Natural circulation boiler |
| D. | Forced circulation boiler |
| Answer» D. Forced circulation boiler | |
| 511. |
_The diameter of a cylindrical shell of a Scotch marine boiler varies from$? |
| A. | 1.5 to 2 m |
| B. | 2.5 to 3.5 m |
| C. | 3.5 to 4.5 m |
| D. | None of these |
| Answer» C. 3.5 to 4.5 m | |
| 512. |
_The length of shell of a Locomotive boiler is$? |
| A. | 1 m |
| B. | 2 m |
| C. | 3 m |
| D. | 4 m |
| Answer» E. | |
| 513. |
_Pick up the wrong statement about critical condition of steam$? |
| A. | Latent heat is zero |
| B. | Liquid directly becomes steam |
| C. | Specific volume of steam and liquid is same |
| D. | This is the maximum pressure limit |
| Answer» E. | |
| 514. |
_Throttle governing of steam engines is a method of controlling the engine output by varying$? |
| A. | Volume of intake steam |
| B. | Pressure of intake steam |
| C. | Temperature of intake steam |
| D. | All of these |
| Answer» C. Temperature of intake steam | |
| 515. |
_The function of injector used in small capacity boilers is to$? |
| A. | Create vacuum |
| B. | Inject chemical solution in feed pump |
| C. | Pump water, similar to boiler feed pump |
| D. | Add make up water in the system |
| Answer» D. Add make up water in the system | |
| 516. |
_Which of the following substance will have same percentage in both proximate and ultimate analysis?$? |
| A. | Ash |
| B. | Volatile matter |
| C. | Moisture |
| D. | Hydrogen |
| Answer» B. Volatile matter | |
| 517. |
_The fire tubes in a Scotch marine boiler are$? |
| A. | Horizontal |
| B. | Vertical |
| C. | Inclined |
| D. | None of these |
| Answer» B. Vertical | |
| 518. |
_Thermal efficiency of well maintained boiler will be of the order$? |
| A. | 40 % |
| B. | 50 % |
| C. | 75 % |
| D. | 90 % |
| Answer» E. | |
| 519. |
_The efficiency of a boiler is defined as$? |
| A. | Ratio of heat actually used in producing steam to the heat liberated in the furnace |
| B. | Ratio of the mass of steam produced to the mass of total water supplied in a given time |
| C. | Ratio of the heat liberated in the furnace to the heat actually used in producing steam |
| D. | None of the above |
| Answer» B. Ratio of the mass of steam produced to the mass of total water supplied in a given time | |
| 520. |
_The mechanical draught _________ with the amount of smoke.$? |
| A. | Increases |
| B. | Decreases |
| C. | Does not effect |
| D. | None of these |
| Answer» C. Does not effect | |
| 521. |
_Film boiling occurs at$? |
| A. | Very low pressure |
| B. | Atmospheric pressures |
| C. | Medium pressures |
| D. | Very high pressures |
| Answer» E. | |
| 522. |
_Lancashire boiler is$? |
| A. | Stationary fire tube boiler |
| B. | Internally fired boiler |
| C. | Horizontal boiler |
| D. | All of these |
| Answer» E. | |
| 523. |
_The critical pressure ratio for initially dry saturated steam is$? |
| A. | 0.546 |
| B. | 0.577 |
| C. | 0.582 |
| D. | 0.601 |
| Answer» C. 0.582 | |
| 524. |
_Incomplete combustion can be best judged by$? |
| A. | Smoky chimney exit |
| B. | Excess air in flue gases |
| C. | Measuring carbon monoxide in flue gases |
| D. | Measuring temperature of flue gases at exit of furnace |
| Answer» D. Measuring temperature of flue gases at exit of furnace | |
| 525. |
_When the total heat of steam is h kJ/kg and the sensible heat of feed water is hf1 kJ/kg, then the factor of evaporation is given by$? |
| A. | (h - hf1)/2257 |
| B. | (h + hf1)/2257 |
| C. | (h √ó hf1)/2257 |
| D. | None of these |
| Answer» B. (h + hf1)/2257 | |
| 526. |
_The ratio of the volume at cut-off to the swept volume is called$? |
| A. | Cut-off ratio |
| B. | Expansion ratio |
| C. | Clearance ratio |
| D. | None of these |
| Answer» B. Expansion ratio | |
| 527. |
_In water tube boilers$? |
| A. | Water passes through the tubes which are surrounded by flames and hot gases |
| B. | The flames and hot gases pass through the tubes which are surrounded by water |
| C. | Forced circulation takes place |
| D. | None of these |
| Answer» B. The flames and hot gases pass through the tubes which are surrounded by water | |
| 528. |
_The purpose of governing in steam turbines is to$? |
| A. | Maintain the speed of the turbine |
| B. | Reduce the effective heat drop |
| C. | Reheat the steam and improve its quality |
| D. | Completely balance against end thrust |
| Answer» B. Reduce the effective heat drop | |
| 529. |
_The ratio of the useful heat drop to the isentropic heat drop is called$? |
| A. | Condenser efficiency |
| B. | Nozzle efficiency |
| C. | Boiler efficiency |
| D. | Vacuum efficiency |
| Answer» C. Boiler efficiency | |
| 530. |
_The function of a safety valve is$? |
| A. | To blow off steam when the pressure of steam inside the boiler exceeds the working pressure |
| B. | To indicate the water level inside the boiler to an observer |
| C. | To measure pressure of steam inside the steam boiler |
| D. | None of the above |
| Answer» B. To indicate the water level inside the boiler to an observer | |
| 531. |
_The fire tubes in a Locomotive boiler has __________ diameter.$? |
| A. | 4.75 mm |
| B. | 5.47 mm |
| C. | 7.45 mm |
| D. | 47.5 mm |
| Answer» E. | |
| 532. |
_The shell of the Cochran boiler is made hemispherical$? |
| A. | To give maximum space and strength |
| B. | To withstand the pressure of steam inside the boiler |
| C. | Both (A) and (B) |
| D. | None of the above |
| Answer» D. None of the above | |
| 533. |
_The steam leaves the nozzle at a$? |
| A. | High pressure and a low velocity |
| B. | High pressure and a high velocity |
| C. | Low pressure and a low velocity |
| D. | Low pressure and a high velocity |
| Answer» E. | |
| 534. |
_The coal requirement per kW hour generation in the thermal power plant is of the order of$? |
| A. | 0.1 to 0.2 kg |
| B. | 0.2 to 0.4 kg |
| C. | 0.6 to 0.8 kg |
| D. | 1.0 to 1.5 kg |
| Answer» D. 1.0 to 1.5 kg | |
| 535. |
_In a reaction turbine when the degree of reaction is zero, then there is$? |
| A. | No heat drop in moving blades |
| B. | No heat drop in fixed blades |
| C. | Maximum heat drop in moving blades |
| D. | Maximum heat drop in fixed blades |
| Answer» B. No heat drop in fixed blades | |
| 536. |
_The length of Cornish boiler is of the order of$? |
| A. | 24 m |
| B. | 35 m |
| C. | 57.5 m |
| D. | 79 m |
| Answer» D. 79 m | |
| 537. |
_De-Laval turbines are mostly used$? |
| A. | Where low speeds are required |
| B. | For small power purposes and low speeds |
| C. | For large power purposes |
| D. | For small power purposes and high speeds |
| Answer» E. | |
| 538. |
_In a single acting steam engine$? |
| A. | The steam is admitted on one side of the piston and one working stroke is produced during each revolution of the crankshaft |
| B. | The steam is admitted, in turn, on both sides of the piston and one working stroke is produced during each revolution of the crankshaft |
| C. | The steam is admitted on one side of the piston and two working strokes are produced during each revolution of the crankshaft |
| D. | The steam is admitted, in turn, on both sides of the piston and two working strokes are produced during each revolution of the crankshaft |
| Answer» B. The steam is admitted, in turn, on both sides of the piston and one working stroke is produced during each revolution of the crankshaft | |
| 539. |
_In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is _________ the relative velocity of steam at inlet tip of the blade.$? |
| A. | Equal to |
| B. | Less than |
| C. | Greater than |
| D. | None of these |
| Answer» B. Less than | |
| 540. |
_The ratio of the energy required to produce the artificial draught (expressed in meters head or J/kg of flue gas) to the mechanical equivalent of extra heat carried away per kg of flue gases due to natural draught, is known as$? |
| A. | Efficiency of the boiler |
| B. | Efficiency of the chimney |
| C. | Efficiency of the fan |
| D. | Power of the boiler |
| Answer» C. Efficiency of the fan | |
| 541. |
_A condenser in a steam power plant$? |
| A. | Increases expansion ratio of steam |
| B. | Reduces back pressure of steam |
| C. | Reduces temperature of exhaust steam |
| D. | All of these |
| Answer» E. | |
| 542. |
_With increase in load, radiant superheater has$? |
| A. | Drooping characteristic |
| B. | Linear characteristic |
| C. | Rising characteristic |
| D. | Flat characteristic |
| Answer» B. Linear characteristic | |
| 543. |
_If the critical pressure ratio for steam is 0.546, then the steam is initially$? |
| A. | Wet steam |
| B. | Dry saturated steam |
| C. | Superheated steam |
| D. | None of these |
| Answer» D. None of these | |
| 544. |
_The draught (in mm of water), for maximum discharge of flue gases through the chimney, is given by (where H = Height of the chimney in meters, and T1 = Absolute temperature of air outside the chimney in K)$? |
| A. | T1 /88.25H |
| B. | 88.25H/T1 |
| C. | T1 /176.5H |
| D. | 176.5H/T1 |
| Answer» E. | |
| 545. |
_Hard coke is produced by carburization of coal at$? |
| A. | Atmospheric temperature |
| B. | 500-600°C |
| C. | 700-850°C |
| D. | 950-1100°C |
| Answer» E. | |
| 546. |
_The specific heat of superheated steam in kcal/kg is generally of the order of$? |
| A. | 0.1 |
| B. | 0.3 |
| C. | 0.5 |
| D. | 0.8 |
| Answer» D. 0.8 | |
| 547. |
_The pressure at which latent heat of vaporisation of water is zero, is$? |
| A. | Below atmospheric pressure |
| B. | 1 kg/cm² |
| C. | 100 kg/cm² |
| D. | 225.6 kg/cm² |
| Answer» E. | |
| 548. |
_The turbine blades are$? |
| A. | Straight |
| B. | Circular |
| C. | Curved |
| D. | None of these |
| Answer» D. None of these | |
| 549. |
_Latent heat of dry steam at atmospheric pressure is equal to$? |
| A. | 539 kcal/ kg |
| B. | 539 BTU/ lb |
| C. | 427 kcal/ kg |
| D. | 100 kcal/ kg |
| Answer» B. 539 BTU/ lb | |
| 550. |
_The aim of a compound steam engine is$? |
| A. | To reduce the ratio of expansion in each cylinder |
| B. | To reduce the length of stroke |
| C. | To reduce the temperature range in each cylinder |
| D. | All of the above |
| Answer» E. | |