In the crankcase method of scavenging, the air pressure is produced by_________________?

Related Mcqs:

1. Crankcase explosion in I.C. engines usuall occurs as ___________________?

   A. first a mild explosion followed by a bi explosion
   B. first a big explosion followed by a mil explosion
   C. both mild and big explosions occi simultaneously
   D. never occurs
   E. unpredictable

2. Scavenging air in diesel engine means___________________?

   A. air used for combustion sent under pres-sure
   B. forced air for cooling cylinder
   C. burnt air containing products of combustion
   D. air used for forcing burnt gases out of engine’s cylinder during the exhaust period
   E. air fuel mixture

3. Does the supply of scavenging air at a density greater than that of atmosphere mean engine is supercharged ?

   A. yes
   B. no
   C. to some extent
   D. unpredictable
   E. depends on other factors

4. Scavenging air is supplied to a two-stroke engine at a density greater than that of atmosphere. This means the engine is__________________?

   A. Supercharged
   B. Not supercharged
   C. Charged
   D. Supercharged provided its speed is low

5. The term scavenging is generally associated with______________________?

   A. 2-stroke cycle engines
   B. 4-stroke cycle engines
   C. aeroplane engines
   D. diesel engines
   E. high efficiency engines

6. Scavenging is usually done to increase__________________?

   A. thermal efficiency
   B. speed
   C. power output
   D. fuel consumption
   E. all of the above

7. In loop scavenging, the top of the piston is________________?

   A. flat
   B. contoured
   C. slanted
   D. depressed
   E. convex shaped

8. The thermal efficiency of a petrol engine of two stroke with crank case scavenging as compared to four stroke petrol engine with same comperssion ratio will be_____________________?

   A. higher
   B. lower
   C. same
   D. depends on size of engine
   E. unpredictable.

9. The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be________________?

   A. higher
   B. lower
   C. remain unaffected
   D. unpredictable
   E. none of the above

10. 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________________?

    A. Lean mixture
    B. Chemically correct fuel air ratio
    C. Rich mixture
    D. Unpredictable