In a cycle, the spark lasts roughly for ____________________?

Related Mcqs:

1. The spark plug gap is normally maintained at________________?

   A. 0.1 to 0.2 mm
   B. 0.2 to 0.4 mm
   C. 0.45 to 0.6 mm
   D. 0.6 to 0.8 mm
   E. 0.8 to 1 mm

2. In order to prevent knock in the S.I. engines, the charge away from the spark plug should have___________________?

   A. low temperature
   B. low density
   C. long ignition delay
   D. rich mixture
   E. all of the above

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

   A. auto ignition
   B. preignition
   C. retarded ignition
   D. accelerated ignition
   E. detonation

4. In petrol engines, advancing the spark timing will_______________?

   A. increase the knocking tendency
   B. decrease the knocking tendency
   C. not affect the knocking tendncy
   D. increase or decrease knocking tendency depending on strenght and time of spark
   E. unpredictable

5. With increase in engine speed, the ignition of spark in petrol engine has to be __________________?

   A. Unaltered
   B. Increased
   C. Decreased
   D. Advanced

6. The air standard efficiency of an Otto cycle compared to diesel cycle for the given compression ratio is__________________?

   A. same
   B. less
   C. more
   D. more or less depending on power rating
   E. unpredictable

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

   A. more
   B. less
   C. same
   D. more upto some load and then less
   E. it may be less or more depending on several other factors

8. The efficiency of the ideal diesel cycle is ________ than that of Otto cycle, for the same compression ratio

   A. Higher
   B. Lower
   C. Equal
   D. None of these

   Submitted by: Faheem Zaman Dhaunroo

9. In a typical medium speed 4-stroke cycle diesel engine the inlet valve_____________________?

   A. opens at 20° before top dead center and closes at 35° after the bottom dead center
   B. opens at top dead center and closes at bottom dead center
   C. opens at 10° after top dead center and closes 20° before the bottom dead center
   D. may open or close anywhere
   E. remains open for 200°.

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

    A. compression starts at 35° after bottom dead center and ends at top dead center
    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. none of the above