McqMate
1. |
The range of mechanical efficiency for automobile is |
A. | 0-30% |
B. | 30-50% |
C. | 70-80% |
D. | 90-100% |
Answer» C. 70-80% |
2. |
The measurement of fractioned power by Willans line is applicable to |
A. | ci engine at particular speed |
B. | si engine at particular speed |
C. | any engine at particular speed |
D. | none of the above |
Answer» B. si engine at particular speed |
3. |
Morse test is only applicable to |
A. | single cylinder si engine |
B. | single cylinder ci engine |
C. | multicylinder ci engine |
D. | single and multi cylinder si & ci engine |
Answer» C. multicylinder ci engine |
4. |
The most accurate method of determining friction power is by |
A. | willans line |
B. | morse test |
C. | motoring test |
D. | measurement of brake and indicated power |
Answer» D. measurement of brake and indicated power |
5. |
In the air base method of measuring air flow, the air base is provided to |
A. | damp out the pulsation |
B. | have a constant temperature |
C. | have a constant flow |
D. | provide constant velocity of flow |
Answer» C. have a constant flow |
6. |
The air box/swept volume ratio should be in the range for single cylinder engine |
A. | 10-100% |
B. | 200-300% |
C. | 500-600% |
D. | 10 |
Answer» C. 500-600% |
7. |
The best method of measuring speed is by |
A. | mechanical tachometer |
B. | electrical tachometer |
C. | magnetic pick up |
D. | none of the above |
Answer» A. mechanical tachometer |
8. |
flame ionization detector is used for measuring |
A. | hc |
B. | co |
C. | nox |
D. | co2 |
Answer» A. hc |
9. |
Chemilumme scene analyzer is used for measuring |
A. | hc |
B. | co |
C. | nox |
D. | co2 |
Answer» C. nox |
10. |
Non disprasive infrared analyzer is widely accepted instrument for measuring |
A. | unburnt hydrocarbon |
B. | carbon monoxide |
C. | carbon dioxide |
D. | nox |
Answer» B. carbon monoxide |
11. |
If n is the rpm, number of power strokes per minute in a four stroke engine is |
A. | n/2 |
B. | n |
C. | 2n |
D. | 4n |
Answer» A. n/2 |
12. |
If n is the rpm, number of power strokes per minute in a two stroke engine is |
A. | n/2 |
B. | n |
C. | 2n |
D. | 4n |
Answer» B. n |
13. |
mechanical efficiency is the ratio of |
A. | frictional power to brake power |
B. | frictional power to indicated power |
C. | brake power to indicated power |
D. | indicated power to frictional power |
Answer» C. brake power to indicated power |
14. |
volumetric efficiency is a measure of |
A. | power of the engine |
B. | speed of the engine |
C. | breathing capacity of the engine |
D. | pressure rise in the cylinder |
Answer» C. breathing capacity of the engine |
15. |
thermal efficiency varies |
A. | inversely as specific fuel consumption |
B. | directly as specific fuel consumption |
C. | as square as specific fuel consumption |
D. | as root as specific fuel consumption |
Answer» A. inversely as specific fuel consumption |
16. |
The spark timing and combustion rate should be such that |
A. | one half of the total pressure occurs at tdc |
B. | ignition delay is reduced |
C. | peak pressure occurs at tdc |
D. | none of the above |
Answer» A. one half of the total pressure occurs at tdc |
17. |
Indicated power is directly proportional to |
A. | air consumption |
B. | torque |
C. | cylinder peak pressure |
D. | none of the above |
Answer» A. air consumption |
18. |
The brake thermal efficiency of SI engine is in the range of |
A. | 35-60% |
B. | 25-35 |
C. | 60-80 |
D. | none of the above |
Answer» B. 25-35 |
19. |
Performance m ep shows |
A. | indicated power vs speed |
B. | both vs soeed under various conditions |
C. | bmep vs piston speed under various condition |
D. | nth vs speed under various condition |
Answer» C. bmep vs piston speed under various condition |
20. |
If performance of SI engine of different manufacturer having different capacities size and systems are to be compared, the common parameter would be |
A. | engine cylinder diameter |
B. | b.h.p. |
C. | speed |
D. | mep |
Answer» D. mep |
21. |
Endurance test for IC engine is conducted for |
A. | 100hrs |
B. | 200 hrs |
C. | 400 hrs |
D. | 500 hrs |
Answer» D. 500 hrs |
22. |
Which of the following factor will not assist in improving thermal efficiency of a CI engine |
A. | fine atomization and even distribution of fuel |
B. | minimum heat loss during combustion |
C. | clear exhaust |
D. | high surface to volume ratio |
Answer» D. high surface to volume ratio |
23. |
which statement is correct |
A. | morse test can be conducted on petrol engine |
B. | morse test can be conducted on diesel engine |
C. | conducted only on multicylinder engines |
D. | none of the above |
Answer» C. conducted only on multicylinder engines |
24. |
Rope brake dynamometer falls under the category of |
A. | hydraulic dynamometer |
B. | transmission type dynamometer |
C. | torsion type dynamometer |
D. | mechanical friction type dynamometer |
Answer» D. mechanical friction type dynamometer |
25. |
Prony brakes are used for testing |
A. | small engine |
B. | large capacity engines |
C. | slow speed engines |
D. | high speed engines |
Answer» A. small engine |
26. |
Which of the following is performed for super charging of IC engine? |
A. | roots blower |
B. | axial flow compressor |
C. | sliding vane type compressor |
D. | reciprocating compressor |
Answer» B. axial flow compressor |
27. |
From the engine indicator diagram we obtain |
A. | imep |
B. | bmep |
C. | mechanical efficiency |
D. | relative efficiency |
Answer» A. imep |
28. |
Most accurate dynamometer is |
A. | prony brake type |
B. | hydraulic type |
C. | swinginf field type |
D. | eddy current type |
Answer» C. swinginf field type |
29. |
Most commonly used dynamometer on account of its simplicity of construction is the |
A. | brake type |
B. | hydraulic type |
C. | swinginf field type |
D. | eddy current type |
Answer» A. brake type |
30. |
bmep in an engine depends up on its |
A. | speed only |
B. | torque only |
C. | speed and torque |
D. | speed and power |
Answer» B. torque only |
31. |
Brake thermal efficiency of SI engine usually varies between |
A. | 25-30 % |
B. | 30-60 % |
C. | 60-80% |
D. | more than 80 % |
Answer» A. 25-30 % |
32. |
The brake power is the |
A. | power available at the output shaft |
B. | energy developed inside the cylinder block |
C. | energy lost due to friction |
D. | none of the above |
Answer» A. power available at the output shaft |
33. |
The total power developed by the combustion of fuel is |
A. | bp |
B. | ip |
C. | fp |
D. | none of the above |
Answer» B. ip |
34. |
Mean effective pressure is the pressure |
A. | pressure acting on the crank shaft |
B. | which is acting on the piston throughout the power stroke |
C. | pressure required to inject the fuel |
D. | none of the above |
Answer» B. which is acting on the piston throughout the power stroke |
35. |
Fuel Air ratio is |
A. | mass of fuel to mass of air |
B. | reciprocal of air fuel ratio |
C. | which effects the combustion phenomenon |
D. | all of the above |
Answer» D. all of the above |
36. |
specific fuel consumption is |
A. | amount of fuel consumed per unit power developed per hour |
B. | amount of fuel consumed per unit indicated power per hour |
C. | amount of fuel consumed per hour |
D. | all of the above |
Answer» A. amount of fuel consumed per unit power developed per hour |
37. |
Heat balance sheet indicates |
A. | amount of heat energy consumed in the combustion chamber |
B. | brake up of the total energy input into different parts |
C. | amount of energy lost through exhaust |
D. | all of the above |
Answer» B. brake up of the total energy input into different parts |
38. |
The frictional power is |
A. | bp + ip |
B. | bp- ip |
C. | bp* ip |
D. | none of the above |
Answer» B. bp- ip |
39. |
Identify the correct statement |
A. | power friction means less brake power |
B. | lower friction means more brake power |
C. | high friction means high brake power |
D. | lower friction means high brake specific fuel consumption |
Answer» B. lower friction means more brake power |
40. |
Willians line method is applicable to |
A. | si |
B. | ci |
C. | both |
D. | none of the above |
Answer» A. si |
41. |
The ratio of indicated thermal efficiency to the air std cycle efficiency is called |
A. | net efficiency |
B. | efficiency ratio |
C. | relative efficiency |
D. | overall efficiency |
Answer» C. relative efficiency |
42. |
As compare to winter, during summer, volumetric efficiency of IC engine will |
A. | increase |
B. | decrease |
C. | same |
D. | unpredictable |
Answer» B. decrease |
43. |
Pick up the wrong statement |
A. | supercharging reduces knocking in diesel engine |
B. | there can be limited supercharging in petrol engine because of detonation |
C. | supercharging at high altitudes is essential |
D. | supercharging results in to fuel economy |
Answer» D. supercharging results in to fuel economy |
44. |
The ratio of BP to IP of an engine is |
A. | thermal effi |
B. | brake thermal effi |
C. | mechanical efficiency |
D. | overall efficiency |
Answer» C. mechanical efficiency |
45. |
Volumetric efficiency of supercharged engine is |
A. | 1 |
B. | cant determine |
C. | greater than 1 |
D. | less than 1 |
Answer» C. greater than 1 |
46. |
volumetric efficiency of naturally aspirated engine is |
A. | 1 |
B. | cant determine |
C. | greater than 1 |
D. | less than 1 |
Answer» D. less than 1 |
47. |
The mean effective pressure indicates the |
A. | maximum pressure developed |
B. | minimum pressure developed |
C. | average pressure |
D. | instanteneous pressure at any instant |
Answer» C. average pressure |
48. |
The ratio of BMEP to IMEP is called |
A. | mechanical efiiciency |
B. | overall efficiency |
C. | volumetric efficiency |
D. | indicated thermal effi |
Answer» A. mechanical efiiciency |
49. |
The powern actually developed by the engine is called |
A. | theoretical power |
B. | actual power |
C. | ip |
D. | none of the above |
Answer» C. ip |
50. |
The BP of diesel engine, keeping other parameters constant, can be increased by |
A. | decreasing the density of intake air |
B. | incrasing the temperature of intake air |
C. | increasing the pressure of intake air |
D. | decreasing the pressure of intake air |
Answer» C. increasing the pressure of intake air |
51. |
Motoring test is carried out on an IC engine to determine |
A. | bp |
B. | ip |
C. | fp |
D. | none of the above |
Answer» C. fp |
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