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.
| 1. |
A _________ in a boiler is used to put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit. |
| A. | low off cock |
| B. | usible plug |
| C. | top valve |
| D. | afety valve |
| Answer» C. top valve | |
| 2. |
Gradually increasing temperature of flue gases at inlet to chimney for given steam outputs is an indication of |
| A. | igher effectiveness of boiler |
| B. | igh calorific value coal being burnt |
| C. | ouling of heat transfer surfaces |
| D. | aising of steam temperature |
| Answer» D. aising of steam temperature | |
| 3. |
The mechanical draught _________ with the amount of smoke. |
| A. | ncreases |
| B. | ecreases |
| C. | oes not effect |
| D. | one of these |
| Answer» C. oes not effect | |
| 4. |
Proximate analysis of fuel is determination of percentage of |
| A. | arbon, hydrogen, nitrogen, sulphur, moisture |
| B. | ixed carbon, ash, volatile matter, moisture |
| C. | igher calorific value |
| D. | ower calorific value |
| Answer» C. igher calorific value | |
| 5. |
Ultimate analysis of fuel is determination of percentage of |
| A. | arbon, hydrogen, nitrogen, sulphur, moisture |
| B. | ixed carbon, ash, volatile matter, moisture |
| C. | igher calorific value |
| D. | ower calorific value |
| Answer» B. ixed carbon, ash, volatile matter, moisture | |
| 6. |
The blade friction in the impulse turbine reduces the velocity of steam by __________ while it passes over the blades. |
| A. | 0 to 15% |
| B. | 5 to 20% |
| C. | 0 to 30% |
| D. | 0 to 40% |
| Answer» B. 5 to 20% | |
| 7. |
The temperature of flue gases at air heater outlet should be |
| A. | 00°C |
| B. | bove dew point temperature of flue gases |
| C. | elow dew point temperature of flue gases |
| D. | ess than wet bulb temperature of flue gases |
| Answer» C. elow dew point temperature of flue gases | |
| 8. |
A compound steam engine in which piston rods of high pressure and low pressure cylinders ' are attached to two different cranks set at 180° to each other, is called |
| A. | eceiver type compound engine |
| B. | andem type compound engine |
| C. | oolf type compound engine |
| D. | oth (A) and (B) |
| Answer» D. oth (A) and (B) | |
| 9. |
A compound steam engine in which piston rods of high pressure and low pressure cylinders are attached to two different cranks set at 90° to each other, is called |
| A. | eceiver type compound engine |
| B. | andem type compound engine |
| C. | oolf type compound engine |
| D. | oth (A) and (B) |
| Answer» B. andem type compound engine | |
| 10. |
Expanding steam to a very low pressure (high vacuum) in steam engines is |
| A. | esirable |
| B. | conomical |
| C. | ssential |
| D. | neconomical |
| Answer» E. | |
| 11. |
The critical pressure ratio for initially superheated steam is __________ as compared to initially dry saturated steam. |
| A. | ore |
| B. | ess |
| C. | ame |
| D. | one of these |
| Answer» C. ame | |
| 12. |
Which is not correct statement about effect of sulphur in fuel? |
| A. | t has heating value |
| B. | t helps in electrostatic precipitation of ash in flue gases |
| C. | t leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low |
| D. | t erodes furnace walls |
| Answer» E. | |
| 13. |
The principal function of a stop valve is to |
| A. | ontrol the flow of steam from the boiler to the main pipe and to shut off the steam completely when required |
| B. | mpty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler |
| C. | ut off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit |
| D. | ncrease the temperature of saturated steam without raising its pressure |
| Answer» B. mpty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler | |
| 14. |
The best suited coal for chain or traveling grate stoker boiler is |
| A. | oking coal |
| B. | on-coking or free burning coal |
| C. | ulverized coal |
| D. | igh sulphur coal |
| Answer» C. ulverized coal | |
| 15. |
Duplex feed pumps are used in small steam boilers. These operate on the principle of |
| A. | entrifugal pump |
| B. | xial flow pump |
| C. | ear pump |
| D. | eciprocating pump |
| Answer» E. | |
| 16. |
In a boiler, the heat is lost |
| A. | o dry flue gases |
| B. | n moisture present in the fuel |
| C. | o steam formed by combustion of hydrogen per kg of fuel |
| D. | ll of the above |
| Answer» E. | |
| 17. |
The high pressure and low pressure cylinders in a Woolf type compound engine are regarded as having cranks |
| A. | 80° to each other |
| B. | 0° to each other |
| C. | ° to each other |
| D. | one of these |
| Answer» B. 0° to each other | |
| 18. |
At which pressure the properties of water and steam become identical |
| A. | .1 kg/cm² |
| B. | kg/cm² |
| C. | 00 kg/cm² |
| D. | 25.6 kg/cm² |
| Answer» E. | |
| 19. |
Which of the following boiler is best suited to meet the fluctuating demand of steam? |
| A. | ocomotive boiler |
| B. | ancashire boiler |
| C. | ornish boiler |
| D. | abcock and Wilcox boiler |
| Answer» B. ancashire boiler | |
| 20. |
Which of the following gases has the highest calorific value? |
| A. | roducer gas |
| B. | oal gas |
| C. | ater gas |
| D. | last furnace gas |
| Answer» C. ater gas | |
| 21. |
The pressure of steam in the engine cylinder at the beginning of the stroke is ________ the boiler pressure. |
| A. | qual to |
| B. | ess than |
| C. | igher than |
| D. | one of these |
| Answer» C. igher than | |
| 22. |
The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine. |
| A. | ame |
| B. | ess |
| C. | ore |
| D. | one of these |
| Answer» C. ore | |
| 23. |
The relative heat absorption for successively added equal areas of boiler convection heating surfaces |
| A. | ncreases |
| B. | ecreases |
| C. | emain unaffected |
| D. | irst increases and then decreases |
| Answer» C. emain unaffected | |
| 24. |
The fittings mounted on the boiler for its proper and safe functioning is a |
| A. | ater level indicator |
| B. | ressure gauge |
| C. | afety valve |
| D. | ll of these |
| Answer» E. | |
| 25. |
A supercritical boiler is one that operates above the pressure and temperature of following values |
| A. | 00 kg/cm² and 540°C |
| B. | kg/cm² and 100°C |
| C. | 18 kg/cm² abs and 373°C |
| D. | 18 kg/cm² abs and 540°C |
| Answer» D. 18 kg/cm² abs and 540°C | |
| 26. |
Steam in water tube boiler as compared to fire tube boiler |
| A. | an be raised rapidly |
| B. | s raised at slower rate |
| C. | s raised at same rate |
| D. | ould be raised at fast/slow rate depending on design |
| Answer» B. s raised at slower rate | |
| 27. |
One kilowatt-hour energy is equivalent to |
| A. | 000 J |
| B. | 60 kJ |
| C. | 600 kJ |
| D. | 600 kW/sec |
| Answer» D. 600 kW/sec | |
| 28. |
The behavior of coal in a furnace is determined by |
| A. | he content of sulphur |
| B. | he content of ash and heating value |
| C. | he proximate analysis |
| D. | he exact analysis |
| Answer» D. he exact analysis | |
| 29. |
By compounding the expansion of steam in two or more cylinders, the length of stroke |
| A. | oes not change |
| B. | ncreases |
| C. | ecreases |
| D. | one of these |
| Answer» D. one of these | |
| 30. |
The working pressure range for a LaMont boiler is |
| A. | .5 to 10 MN/m² |
| B. | to 15 MN/m² |
| C. | .5 to 15 MN/m² |
| D. | .5 to 20 MN/m² |
| Answer» E. | |
| 31. |
1 kg.m is equal to |
| A. | .81 Joules |
| B. | 02 Joules |
| C. | 27 Joules |
| D. | one of these |
| Answer» B. 02 Joules | |
| 32. |
Water tube boilers are |
| A. | nternally fired |
| B. | xternally fired |
| C. | nternally as well as externally fired |
| D. | one of these |
| Answer» C. nternally as well as externally fired | |
| 33. |
Sublimation region is the region where |
| A. | olid and vapor phases are in equilibrium |
| B. | olid and liquid phases are in equilibrium |
| C. | iquid and vapor phases are in equilibrium |
| D. | olid, liquid and vapor phases are in equilibrium |
| Answer» B. olid and liquid phases are in equilibrium | |
| 34. |
The steam temperature with increase in load in case of a boiler fitted with radiation superheater |
| A. | ncreases |
| B. | ecreases |
| C. | emain unaffected |
| D. | irst increases and then decreases |
| Answer» C. emain unaffected | |
| 35. |
The effect of super-saturation is that the |
| A. | ass of the steam discharged increases |
| B. | ntropy and specific volume of the steam increases |
| C. | xit velocity of steam reduces |
| D. | ll of these |
| Answer» E. | |
| 36. |
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 × hf1)/2257 |
| D. | one of these |
| Answer» B. h + hf1)/2257 | |
| 37. |
In forced circulation type boiler |
| A. | eating takes place at bottom and the water supplied at bottom gets converted into the mixture of steam bubbles and hot water which rise to drum |
| B. | ater is supplied in drum and through down comers located in atmospheric condition it passes to the water wall and rises to drum in the form of mixture of water and steam |
| C. | eed pump is employed to supplement natural circulation in water wall type furnace |
| D. | ater is converted into steam in one pass without any recirculation |
| Answer» E. | |
| 38. |
Green coal, in order to be burnt, must be |
| A. | eated sufficiently |
| B. | urnt in excess air |
| C. | eated to its ignition point |
| D. | urnt as powder |
| Answer» D. urnt as powder | |
| 39. |
Incomplete combustion can be best judged by |
| A. | moky chimney exit |
| B. | xcess air in flue gases |
| C. | easuring carbon monoxide in flue gases |
| D. | easuring temperature of flue gases at exit of furnace |
| Answer» D. easuring temperature of flue gases at exit of furnace | |
| 40. |
The efficiency of the plant __________ with the mechanical draught. |
| A. | ncreases |
| B. | ecreases |
| C. | emains constant |
| D. | one of these |
| Answer» B. ecreases | |
| 41. |
The heat loss in a boiler takes place in the form of |
| A. | eat carried away by flue gases |
| B. | eat carried away by ash |
| C. | oisture present in fuel and steam formed by combustion of hydrogen in fuel |
| D. | ll of the above |
| Answer» E. | |
| 42. |
Water and sediment in fuel oil can be removed by |
| A. | eating the oil in the settling tanks |
| B. | ooling the oil in the settling tanks |
| C. | urning the oil |
| D. | uspension |
| Answer» B. ooling the oil in the settling tanks | |
| 43. |
While steam expands in turbines, theoretically the entropy |
| A. | emains constant |
| B. | ncreases |
| C. | ecreases |
| D. | ehaves unpredictably |
| Answer» B. ncreases | |
| 44. |
Film boiling occurs at |
| A. | ery low pressure |
| B. | tmospheric pressures |
| C. | edium pressures |
| D. | ery high pressures |
| Answer» E. | |
| 45. |
An impulse turbine as compared to a reaction turbine, for a given power has _________ row of blades. |
| A. | qual |
| B. | ess |
| C. | ore |
| D. | one of these |
| Answer» D. one of these | |
| 46. |
The ratio of the clearance volume to the swept volume is called |
| A. | ut-off ratio |
| B. | xpansion ratio |
| C. | learance ratio |
| D. | one of these |
| Answer» D. one of these | |
| 47. |
The ratio of the volume at cut-off to the swept volume is called |
| A. | ut-off ratio |
| B. | xpansion ratio |
| C. | learance ratio |
| D. | one of these |
| Answer» B. xpansion ratio | |
| 48. |
Adiabatic process is |
| A. | ssentially an isentropic process |
| B. | on-heat transfer process |
| C. | eversible process |
| D. | onstant temperature process |
| Answer» C. eversible process | |
| 49. |
The function of a piston in a steam engine is |
| A. | o guide motion of the piston rod and to prevent it from bending |
| B. | o transfer motion from the piston to the cross-head |
| C. | o convert heat energy of the steam into mechanical work id) to exhaust steam from the cylinder at proper moment |
| D. | one of these |
| Answer» D. one of these | |
| 50. |
The overall efficiency of thermal power plant is |
| A. | oiler efficiency, turbine efficiency, generator efficiency |
| B. | ll the three above plus gas cycle efficiency |
| C. | arnot cycle efficiency |
| D. | egenerative cycle efficiency |
| Answer» B. ll the three above plus gas cycle efficiency | |