MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Morse test can be conducted for |
| A. | petrol engines |
| B. | diesel engines |
| C. | multi-cylinder engines |
| D. | all of these |
| Answer» D. all of these | |
| 2. |
The basic requirement of a good combustion chamber is |
| A. | minimum turbulence |
| B. | low compression ratio |
| C. | high thermal efficiency and power output |
| D. | low volumetric efficiency |
| Answer» D. low volumetric efficiency | |
| 3. |
In a four stroke cycle petrol engine, the charge is compressed when both the valves (i.e. inlet valve and exit valve) are closed, |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 4. |
The thermal efficiency of diesel engines on weak mixtures is |
| A. | unaffected |
| B. | lower |
| C. | higher |
| D. | dependent on other factors |
| Answer» D. dependent on other factors | |
| 5. |
The injection pressure in a diesel engine is about |
| A. | 10 bar |
| B. | 100 bar |
| C. | 150 bar |
| D. | 500 bar |
| Answer» C. 150 bar | |
| 6. |
U233 is produced |
| A. | artificially |
| B. | as basic raw material |
| C. | when thorium is irradiated by neutrons |
| D. | by fission of U |
| E. | <sub>238</sub> |
| Answer» D. by fission of U | |
| 7. |
The pressure at the end of compression, in diesel engines, is approximately |
| A. | 10 bar |
| B. | 20 bar |
| C. | 25 bar |
| D. | 35 bar |
| Answer» E. | |
| 8. |
The energy released during the fission of one atom of Uranium - 235 in million electron volts is about |
| A. | 100 |
| B. | 200 |
| C. | 300 |
| D. | 400 |
| Answer» C. 300 | |
| 9. |
Reactors for propulsion applications are designed for |
| A. | any form of uranium |
| B. | natura uranium |
| C. | enriched uranium |
| D. | plutonium |
| Answer» D. plutonium | |
| 10. |
In petrol engine, using a fixed octane rating fuel and fixed compression ratio, supercharging will __________ the knocking tendency. |
| A. | not effect |
| B. | decrease |
| C. | increase |
| Answer» D. | |
| 11. |
The increase of cooling water temperature in petrol engine will __________ the knocking tendency. |
| A. | not effect |
| B. | decrease |
| C. | increase |
| Answer» D. | |
| 12. |
A carburettor is used to supply |
| A. | petrol, air and lubricating oil |
| B. | air and diesel |
| C. | petrol and lubricating oil |
| D. | petrol and air |
| Answer» E. | |
| 13. |
In a diesel engine, the duration between the time of injection and ignition, is known as |
| A. | pre-ignition period |
| B. | delay period |
| C. | period of ignition |
| D. | burning period |
| Answer» C. period of ignition | |
| 14. |
A moderator, in nuclear power plants, is a medium introduced into the fuel mass in order to |
| A. | slow down the speed of fast moving neutrons |
| B. | control the reaction |
| C. | reduce the temperature |
| D. | extract heat from nuclear reaction |
| Answer» B. control the reaction | |
| 15. |
An aftercooler is used to |
| A. | remove impurities from air |
| B. | reduce volume of air |
| C. | cause moisture and oil vapour to drop out |
| D. | cool the air |
| Answer» D. cool the air | |
| 16. |
Where reactor operation is designed with fast neutrons such as in reactors using highly enriched fuel, the moderator used is |
| A. | heavy water |
| B. | graphite |
| C. | carbon dioxide |
| D. | no moderator is needed |
| Answer» E. | |
| 17. |
The ratio of the volume of free air delivery per stroke to the swept volume of the piston, is known as |
| A. | compressor efficiency |
| B. | volumetric efficiency |
| C. | isothermal efficiency |
| D. | mechanical efficiency |
| Answer» C. isothermal efficiency | |
| 18. |
The actual volume of air delivered by a compressor, When reduced to the normal temperature and pressure conditions is called compressor capacity. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 19. |
The ratio of the indicated power to the shaft power or brake power of the motor or engine required to drive the compressor, is called |
| A. | compressor efficiency |
| B. | volumetric efficiency |
| C. | isothermal efficiency |
| D. | mechanical efficiency |
| Answer» E. | |
| 20. |
The maximum combustion pressure in gas turbine is __________ as compared to I.C. engine. |
| A. | more |
| B. | less |
| Answer» C. | |
| 21. |
The compression ratio in a gas turbine is |
| A. | 4 |
| B. | 1 |
| C. | 9 |
| D. | 12 |
| Answer» C. 9 | |
| 22. |
Intercooling in compressors results in saving of power in compressing given volume of air to a given pressure. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 23. |
In a reciprocating air compressor, the compression work per kg of air |
| A. | increases as clearance volume increases |
| B. | decreases as clearance volume increases |
| C. | is independent of clearance volume |
| D. | increases as clearance volume decreases |
| Answer» D. increases as clearance volume decreases | |
| 24. |
The ratio of the volume of charge admitted at N.T.P. to the swept volume of the piston is called |
| A. | mechanical efficiency |
| B. | overall efficiency |
| C. | volumetric efficiency |
| D. | relative efficiency |
| Answer» D. relative efficiency | |
| 25. |
A moderator generally used in nuclear power plants is |
| A. | graphite |
| B. | heavy water |
| C. | concrete |
| D. | graphite and concrete |
| Answer» E. | |
| 26. |
An axial compressor gives optimum performance at high speeds and large volume flows. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 27. |
The degree of reaction in an axial flow compressor is defined as the ratio of static enthalpy rise in the |
| A. | rotor to static enthalpy rise in the stator |
| B. | stator to static enthalpy rise in the rotor |
| C. | rotor to static enthalpy rise in the stage |
| D. | stator to static enthalpy rise in the stage |
| Answer» D. stator to static enthalpy rise in the stage | |
| 28. |
The exhaust valve in a four stroke cycle petrol engine |
| A. | opens at 50 before bottom dead centre and closes at 15 after top dead centre |
| B. | opens at bottom dead centre and closes at top dead centre |
| C. | opens at 50 after bottom dead centre and closes at 15 before top dead centre |
| D. | may open and close anywhere |
| Answer» B. opens at bottom dead centre and closes at top dead centre | |
| 29. |
Nuclear reactors are used |
| A. | to produce heat for thermoelectric power |
| B. | to produce fissionable material |
| C. | to propel ships, submarines, aircrafts |
| D. | all of these |
| Answer» E. | |
| 30. |
The expansion of fuel in a four stroke cycle diesel engine |
| A. | starts at 15 before top dead centre and ends at 30 after top dead centre |
| B. | starts at top dead centre and ends at 30 after top dead centre |
| C. | starts at 15 after top dead centre and ends at 30 before bottom dead centre |
| D. | may start and end anywhere |
| Answer» D. may start and end anywhere | |
| 31. |
The object of supercharging the engine is |
| A. | to reduce mass ofthe engine per brake power |
| B. | to reduce space occupied by the engine |
| C. | to increase the power output of an engine when greater power is required |
| D. | all ofthe above |
| Answer» E. | |
| 32. |
The effective inhibitor of pre-ignition is |
| A. | alcohol |
| B. | water |
| C. | lead |
| D. | none of these |
| Answer» C. lead | |
| 33. |
The purpose of testing an internal combustion engine is |
| A. | to determine the information, which can not be obtained by calculations |
| B. | to conform the data used in design, the validity of which may be doubtful |
| C. | to satisfy the customer regarding the performance of the engine |
| D. | all of the above |
| Answer» E. | |
| 34. |
Pre-ignition is caused by the spontantaneous combustion of the mixture before the end of the compression stroke, and is due to |
| A. | cylinder walls being too hot |
| B. | overheated spark plug points |
| C. | red hot carbon deposits on cylinder walls |
| D. | any one of these |
| Answer» E. | |
| 35. |
The thermal efficiency of diesel engines is about |
| A. | 15% |
| B. | 30% |
| C. | 50% |
| D. | 70% |
| Answer» E. | |
| 36. |
The compensating jet in a carburettor supplies almost constant amount of petrol at all speeds because the |
| A. | jet area is automatically varied depending on the suction |
| B. | the flow from the main jet is diverted to the compensating jet with increase in speed |
| C. | the diameter of the jet is constant and the discharge coefficient is invariant |
| D. | flow is produced due to the static head in the float chamber |
| Answer» E. | |
| 37. |
Ordinary water is sometimes used as moderator when enriched uranium is used as a fuel in nuclear power plants. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 38. |
In a nozzle, whole frictional loss is assumed to occur between |
| A. | inlet and thoroat |
| B. | inlet and outlet |
| C. | throat and exit |
| D. | all of these |
| Answer» D. all of these | |
| 39. |
The critical pressure ratio for initially wet steam is |
| A. | 0.546 |
| B. | 0.577 |
| C. | 0.582 |
| D. | 0.601 |
| Answer» D. 0.601 | |
| 40. |
The impulse reaction turbine has its driving force |
| A. | as an impulsive force |
| B. | as a reaction force |
| C. | partly as an impulsive force and partly as a reaction force |
| D. | none of the above |
| Answer» D. none of the above | |
| 41. |
Thermal equilibrium means that the flow of steam is |
| A. | isothermal |
| B. | isentropic |
| C. | hyperbolic |
| D. | polytropic |
| Answer» C. hyperbolic | |
| 42. |
A regenerative steam cycle renders |
| A. | increased work output per unit mass of steam |
| B. | decreased work output per unit mass of steam |
| C. | increased thermal efficiency |
| D. | decreased work output per unit mass of steam as well as increased thermal efficiency |
| Answer» E. | |
| 43. |
The isentropic enthalpy drop in moving blade is two-third of the isentropic enthalpy drop in fixed blades of a turbine. The degree of reaction will be |
| A. | 0.4 |
| B. | 0.56 |
| C. | 0.67 |
| D. | 1.67 |
| Answer» B. 0.56 | |
| 44. |
The turbine blades do not change the direction of steam issuing from the nozzle. |
| A. | True |
| B. | False |
| Answer» C. | |
| 45. |
The maximum efficiency of a reaction turbine is |
| A. | <img src="/_files/images/mechanical-engineering/steam-nozzles-and-turbines/321-111-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/steam-nozzles-and-turbines/321-111-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/steam-nozzles-and-turbines/321-111-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/steam-nozzles-and-turbines/321-111-4.png"> |
| Answer» C. <img src="/_files/images/mechanical-engineering/steam-nozzles-and-turbines/321-111-3.png"> | |
| 46. |
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 | |
| 47. |
The variation of steam pressure in the nozzle depends upon |
| A. | velocity of steam |
| B. | specific volume of steam |
| C. | dryness fraction of steam |
| D. | all of these |
| Answer» E. | |
| 48. |
The critical pressure ratio for initially dry saturated steam is more as compared to initially wet steam. |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 49. |
In a convergent divergent nozzle, the discharge depends upon the initial conditions of steam and the area of nozzle at throat. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 50. |
The reference fuels for knock rating of spark ignition engines would include |
| A. | iso-octane and alpha-methyl naphthalene |
| B. | normal octane and aniline |
| C. | iso-octane and normal hexane |
| D. | normal heptane and iso-octane |
| Answer» E. | |