mechanical engineering MCQs – Page 156

Practise multiple-choice questions from mechanical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

mechanical engineering Mcqs

1. compressors gas turbines and jet engines 2. theory of machines 3. nuclear power plants 4. engineering materials 5. strength of materials mechanical engineering 6. thermodynamics 7. heat transfer 8. i c engines 9. steam boilers engines nozzles and turbines 10. engineering mechanics 11. fluid mechanics mechanical engineering 12. production technology 13. machine design 14. hydraulic machines 15. workshop technology 16. refrigeration and air conditioning

3101. Which is false statement about advantages of V-type engine_________________?
0

A. improved distribution of air to cylinder

B. compact design requiring lesser space

C. reduced torsional vibration because of shorter crankshaft

D. less overhead clearance

E. casting less liable to distortion

3102. Diesel engines as compared to petrol engines require ______________________?
0

A. no flywheel

B. bigger flywheel

C. flywheel whose size may be less or more depending on several other fac-tors

D. smaller flywheel

E. same size flywheel

3103. The thermal efficiency of a two cycle engine as compared to four cycle engine is_________________?
0

A. it may be less or more depending on several other factors

B. same

C. less

D. more

E. more upto some load and then less

3104. Normal heptane_______________?
0

A. helps to resist auto-ignition

B. accelerates auto-ignition

C. retards auto-ignition

D. has no relation with auto-ighition

E. does not affect auto-ignition

3105. Carbon residue in diesel oil should not be more than___________________?
0

A. 0.50%

B. 1%

C. 0.10%

D. 0.001%

E. 0.01%

3106. In case of gas turbines, the gaseous fuel consumption guarantees are based on________________?
0

A. net calorific value

B. middle heat value

C. high heat value

D. calorific value

E. low heat value

3107. Iso-oct ,ne________________?
0

A. is an index of detonation quality

B. has octane number of 100

C. has octane number of 50

D. is an index of knocking quality

E. has octane number of 0

3108. In petrol engine using a fixed octane rating fuel and fixed compression ratio, super charging will_________________?
0

A. increase or decrease knocking tendency depending on strength and time of spark

B. not affect the knocking tendency

C. unpredictable

D. decrease the knocking tendency

E. increase the knocking tendency

3109. Pick up the wrong statement?
0

A. thermal efficiency of 4-stroke engine is more due to positive scavenging

B. 2-stroke engine can run in any direction

C. petrol engines work on otto cycle

D. In 4-stroke engine, a power stroke is obtained in 4-strokes

E. petrol engines occupy more space than diesel engines for same power output

3110. The firing order in a six stroke I.C. engine is_________________?
0

A. 1-5-2-6-3-4

B. 1-6-2-5-4-3

C. 1-4-2-5-6-3

D. 1-3-6-5-2-4

E. 1-5-3-4-2-6

3111. Auto-ignition reaction time for petrol engine first decreases with increase in fuel air ratio, reaches a minimum value and then increases with subsequent increase in fuel air ratio. The minimum value occurs in the region of________________?
0

A. Rich mixture

B. Chemically correct fuel air ratio

C. Lean mixture

D. Unpredictable

3112. For the same compression ratio_____________________?
0

A. Otto cycle is more efficient than the Diesel

B. Diesel cycle is more efficientthan Otto

C. both Otto and Diesel cycles are, equally efficient

D. compression ratio has nothing to do with efficiency

E. which is more efficient would depend on engine capacity

3113. In a typical medium speed 4-stroke cycle diesel engine________________?
0

A. none of the above

B. compression starts at bottom dead center and ends at top dead center

C. compression starts at 10 before bottom dead center and, ends just before top dead center

D. may start and end anywhere

E. compression starts at 35 after bottom dead center and ends at top dead center

3114. All heat engines utilize_____________________?
0

A. all of the above

B. net claorific value of oil

C. high heat value of oil

D. low heat value of oil

E. calorific value of fuel

3115. Detonation is caused by the following unstable compounds______________________?
0

A. ketones and sulphur compounds

B. peroxides, aldehydes, oxides and sul-phides

C. aldehydes, oxides and ketones

D. peroxides, aldehydes and ketones

E. none of the above

3116. The ignition of charge by some hot surface in the engine cylinder before operation of spark plug is known as________________?
0

A. retarded ignition

B. auto ignition

C. preignition

D. detonation

E. accelerated ignition

3117. The mean effective pressure obtained from engine indicator indicates the________________?
0

A. instantaneous pressure at any instant

B. exhaust pressure

C. average pressure

D. maximum pressure developed

E. minimum pressure

3118. Supercharging is the process of_____________________?
0

A. supplying the intake of an engine with air at a density greater than the density of the surrounding atmosphere

B. injecting excess fuel for raising more load

C. providing forced cooling air

D. raising exhaust pressure

E. supplying compressed air to remove combustion products fully

3119. Supercharging is essential in_____________?
0

A. marine engines

B. diesel engines

C. gas turbines

D. aircraft engines

E. petrol engines

3120. A 4-stroke diesel engine needs about following amount of air_________________?
0

A. 75000 cc per min. per h.p.

B. 75 cc per min. per h.p.

C. 750 cc per min. per h.p.

D. 750000 cc per min. per h.p

E. 7500 cc per min. per h.p.

Previous Next

Showing 3101 to 3120 of 4266 mcqs