McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
Chapters
| 1. |
Advantage of gaseous fuel is that |
| A. | it can be stored easily |
| B. | it can mix easily with air |
| C. | it can displace more air from the engine |
| D. | all of the above |
| Answer» B. it can mix easily with air | |
| 2. |
Paraffins are in general represented by |
| A. | CnHn |
| B. | CnH2n |
| C. | CnH2n+2 |
| D. | CnH2n-6 |
| Answer» C. CnH2n+2 | |
| 3. |
Paraffins have molecular structure of |
| A. | chain saturated |
| B. | chain unsaturated |
| C. | ring saturated |
| D. | ring unsaturated |
| Answer» A. chain saturated | |
| 4. |
Olefins are represented by the formula |
| A. | CnH2n |
| B. | CnH2n+2 |
| C. | CnH2n-4 |
| D. | CnH2n-6 |
| Answer» A. CnH2n | |
| 5. |
Hydrocarbons are decomposed into smaller hydrocarbons by |
| A. | reforming |
| B. | refining |
| C. | cracking |
| D. | polymerization |
| Answer» C. cracking | |
| 6. |
The molecular structure of the straight-run gasoline is changed by |
| A. | cracking |
| B. | reforming |
| C. | reining |
| D. | boiling |
| Answer» B. reforming | |
| 7. |
For SI engines fuels most preferred are |
| A. | aromatics |
| B. | parafins |
| C. | olefins |
| D. | napthenes |
| Answer» A. aromatics | |
| 8. |
For CI engine fuels most preferred are |
| A. | napthenes |
| B. | paraffins |
| C. | olefins |
| D. | aromatics |
| Answer» B. paraffins | |
| 9. |
Octane number of iso-octane is |
| A. | 0 |
| B. | 30 |
| C. | 60 |
| D. | 100 |
| Answer» D. 100 | |
| 10. |
Ignition quality of diesel fuel is indicated by its |
| A. | octane number |
| B. | cetane number |
| C. | fash point |
| D. | fire point |
| Answer» B. cetane number | |
| 11. |
Flash point of fuel oil is |
| A. | minimum temperature to which1 oil is heated in order to give off inflammable vapours in Sufficient quantity to ignite momentarily when brought in contact with a flame |
| B. | temperature at which it solidifies or congeals |
| C. | temperature at which it catches fire without external aid |
| D. | indicated by 90% distillation temperature, i.e. when 90% of sample oil has distilled off |
| Answer» A. minimum temperature to which1 oil is heated in order to give off inflammable vapours in Sufficient quantity to ignite momentarily when brought in contact with a flame | |
| 12. |
Gasohol is a mixture of |
| A. | 90% ethanol + 10% gasoline |
| B. | 10% ethanol +90% gasoline |
| C. | 40% ethanol + 60% gasoline |
| D. | 50% ethanol +50% gasoline |
| Answer» B. 10% ethanol +90% gasoline | |
| 13. |
Stoichiometric air-fuel ratio of petrol is roughly |
| A. | 50:1 |
| B. | 25:1 |
| C. | 15:1 |
| D. | 1:1 |
| Answer» C. 15:1 | |
| 14. |
Venturi in the carburetor results in |
| A. | decrease of air velocity |
| B. | increase of air velocity |
| C. | decrease of fuel flow |
| D. | increase of manifold vacuum |
| Answer» B. increase of air velocity | |
| 15. |
The choke is closed when the engine is |
| A. | accelerating |
| B. | hot |
| C. | cold |
| D. | idling |
| Answer» C. cold | |
| 16. |
Lean air mixture is required during |
| A. | idling |
| B. | starting |
| C. | accelerating |
| D. | cruising |
| Answer» D. cruising | |
| 17. |
The limits of air-fuel for SI engine are |
| A. | 8/1 to 18/1 |
| B. | 8/1 to 50/1 |
| C. | 25/1 to 50/1 |
| D. | 50/1 to 100/1 |
| Answer» A. 8/1 to 18/1 | |
| 18. |
For maximum thermal efficiency, the fuel-air mixture in SI engines should be |
| A. | lean |
| B. | rich |
| C. | stoichiometric |
| D. | may be rich or lean |
| Answer» A. lean | |
| 19. |
During starting petrol engines require |
| A. | stoichiometric mixture |
| B. | lean mixture |
| C. | rich mixture |
| D. | any air-fuel ratio is alright |
| Answer» C. rich mixture | |
| 20. |
Economizer is used to provide enriched mixture during |
| A. | Starling |
| B. | idling |
| C. | cruising |
| D. | full throttle operation |
| Answer» D. full throttle operation | |
| 21. |
When the throttle is suddenly opened, the mixture of the simple carburetor tends to become |
| A. | rich |
| B. | lean |
| C. | stoichiometric |
| D. | not affected |
| Answer» B. lean | |
| 22. |
Precise petrol injection system is |
| A. | direct injection |
| B. | sequential injection |
| C. | throttle body injection |
| D. | port injection |
| Answer» C. throttle body injection | |
| 23. |
The choke in an automobile meant for supplying |
| A. | lean mixture |
| B. | rich mixture |
| C. | stoichiometric mixture |
| D. | weak mixture |
| Answer» B. rich mixture | |
| 24. |
Modern carburetors provide the correct quality of air-fuel mixture during |
| A. | starting |
| B. | idling |
| C. | cruising |
| D. | all conditions |
| Answer» D. all conditions | |
| 25. |
A simple carburetor supplies rich mixture during |
| A. | starting |
| B. | idling |
| C. | cruising |
| D. | accelerating |
| Answer» D. accelerating | |
| 26. |
Fuel injector is used for |
| A. | gas engines |
| B. | CI engines |
| C. | SI engines |
| D. | none of the above |
| Answer» B. CI engines | |
| 27. |
Advantage of air injection system is |
| A. | cheaper fuels can be used |
| B. | mep is high |
| C. | fine atomization and distribution of the fuel |
| D. | all of the above |
| Answer» D. all of the above | |
| 28. |
Commonly used injection system in automobiles is |
| A. | air injection |
| B. | solid injection |
| C. | combination of (a) and (b) |
| D. | none of the above |
| Answer» B. solid injection | |
| 29. |
Fuel injection pressure in solid injection system is around |
| A. | <10 bar |
| B. | 10-20 bar |
| C. | 30-50 bar |
| D. | 200-250 bar |
| Answer» D. 200-250 bar | |
| 30. |
Fuel filters do not use generally |
| A. | oil |
| B. | paper |
| C. | cloth |
| D. | felt |
| Answer» B. paper | |
| 31. |
Fuel is injected in a four-stroke CI engine |
| A. | at the end of suction stroke |
| B. | at the end of expansion stroke |
| C. | at the end of compression stroke |
| D. | at the end of exhaust stroke |
| Answer» C. at the end of compression stroke | |
| 32. |
Injection system in which the pump and the injector nozzle is combined in one housing is known as |
| A. | common rail system |
| B. | distributor system |
| C. | unit injector system |
| D. | individual pump and nozzle system |
| Answer» C. unit injector system | |
| 33. |
Main advantage of pintaux nozzle is |
| A. | better cold starting performance |
| B. | ability to distribute the fuel |
| C. | good penetration |
| D. | good atomization |
| Answer» A. better cold starting performance | |
| 34. |
the most accurate gasoline injection system is |
| A. | direct injection |
| B. | port injection |
| C. | throttle body injection |
| D. | manifold injection |
| Answer» B. port injection | |
| 35. |
Advantage of fuel injection in SI engine is |
| A. | low initial cost |
| B. | low maintenance requirements |
| C. | increased volumetric efficiency |
| D. | none of the above |
| Answer» C. increased volumetric efficiency | |
| 36. |
‘MPFI’ stands for |
| A. | Multi point fuel injection |
| B. | Multi port fuel injection |
| C. | Manifold point fuel injection |
| D. | Manifold port fuel injection |
| Answer» A. Multi point fuel injection | |
| 37. |
In carburetor, Choke is incorporated |
| A. | Before the venturi |
| B. | After the venturi |
| C. | In the venturi |
| D. | Any of the above |
| Answer» A. Before the venturi | |
| 38. |
The following factors affect the process of carburetion |
| A. | Engine speed |
| B. | The temperature of incoming air |
| C. | The volatility of fuel |
| D. | All of the above |
| Answer» D. All of the above | |
| 39. |
In MPFI _____ is used to spray fuel into engine. |
| A. | Engine vacuum |
| B. | Suction pressure of engine |
| C. | Electric pump |
| D. | None of the above |
| Answer» B. Suction pressure of engine | |
| 40. |
L-MPFI system uses |
| A. | port injection |
| B. | direct injection |
| C. | manifold injection |
| D. | throttle body injection |
| Answer» A. port injection | |
| 41. |
D-MPFI system uses |
| A. | port injection |
| B. | manifold injection |
| C. | direct injection |
| D. | throttle body injection |
| Answer» B. manifold injection | |
| 42. |
Common rail injection system uses injection pressures of the order |
| A. | 100-200 bar |
| B. | 200-400 bar |
| C. | 400-600 bar |
| D. | 1500 bar |
| Answer» D. 1500 bar | |
| 43. |
Continuous injection system usually has |
| A. | plunger pump |
| B. | rotary pump |
| C. | gear pump |
| D. | vane pump |
| Answer» B. rotary pump | |
| 44. |
The cold start injector |
| A. | maintain stoichiometric air-fuel ratio |
| B. | provides lean air-fuel ratio |
| C. | gives rich air-fuel ratio |
| D. | is not used for any of the above functions |
| Answer» C. gives rich air-fuel ratio | |
| 45. |
ECU is an electronic injection system used for |
| A. | calculating the appropriate injection timing |
| B. | meeting only certain operating conditions |
| C. | closing the injection valve only |
| D. | none of the above |
| Answer» A. calculating the appropriate injection timing | |
| 46. |
With EFI (ELECTRONIC FUEL INJECTION) of diesel engines |
| A. | sharp start and stop is not possible |
| B. | very high injection pressure can be obtained |
| C. | sudden cylinder cut-off is impossible |
| D. | diagnostic properties are poor |
| Answer» B. very high injection pressure can be obtained | |
| 47. |
EFI system can achieve |
| A. | proper injection timing |
| B. | proper injection quantity |
| C. | proper injection pressure |
| D. | all of the above |
| Answer» D. all of the above | |
| 48. |
The first vehicle in India equipped with MPFI system in Indian automobile industry |
| A. | Tata Indica |
| B. | Daewoo Matiz |
| C. | Maruti Alto |
| D. | Chevrolet spark |
| Answer» B. Daewoo Matiz | |
| 49. |
The fuel in diesel engine is normally injected at pressure of |
| A. | 5-10 kg/cm2 |
| B. | 20-25 kg/cm2 |
| C. | 60-80 kg/cm2 |
| D. | 90-130 kg/cm2 |
| Answer» D. 90-130 kg/cm2 | |
| 50. |
The specific fuel consumption per BHP hour for diesel engine is approximately |
| A. | 0.15 kg |
| B. | 0.2 kg |
| C. | 0.25 kg |
| D. | 0.3 kg |
| Answer» B. 0.2 kg | |
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