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Mechanical Engineering :: Internal Combustion Engines

  1. In a four stroke cycle, the minimum temperature inside the engine cylinder occurs at the

  2. A.

     Beginning of suction stroke

    B.

     End of suction stroke

    C.

     Beginning of exhaust stroke

    D.

     End of exhaust stroke


  3. A diesel engine has

  4. A.

     1 valve

    B.

     2 valves

    C.

     3 valves

    D.

     4 valves


  5. The pressure inside the cylinder is _________ the atmospheric pressure during the exhaust stroke.

  6. A.

     Equal to

    B.

     Below

    C.

     Above

    D.

     None of these


  7. Pick up the false statement

  8. A.

     Thermal efficiency of diesel engine is about 34%

    B.

     Theoretically correct mixture of air and petrol is approximately 15:1

    C.

     High speed compression engines operate on dual combustion cycle

    D.

     S.I. engines are quality governed engines


  9. The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is

  10. A.

     Same

    B.

     More

    C.

     Less

    D.

     Less or more depending on operating conditions


  11. The pressure and temperature at the end of compression stroke in a petrol engine are of the order of

  12. A.

     4-6 kg/cm² and 200-250°C

    B.

     6-12 kg/cm² and 250-350°C

    C.

     12-20 kg/cm² and 350-450°C

    D.

     20-30 kg/cm² and 450-500°C


  13. The brake power is the power available

  14. A.

     In the engine cylinder

    B.

     At the crank shaft

    C.

     At the crank pin

    D.

     None of these


  15. Which one of the following engines will have heavier flywheel than the remaining ones?

  16. A.

     30 kW four-stroke petrol engine running at 1500 r.p.m.

    B.

     30 kW two-stroke petrol engine running at 1500 r.p.m.

    C.

     30 kW two-stroke diesel engine running at 750 r.p.m.

    D.

     30 kW four-stroke diesel engine running at 750 r.p.m.


  17. In a typical medium speed 4-stroke cycle diesel engine the inlet valve

  18. 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


  19. Pick up the wrong statement

  20. A.

     2-stroke engine can run in any direction

    B.

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

    C.

     Thermal efficiency of 4-stroke engine is more due to positive scavenging

    D.

     Petrol engines occupy more space than diesel engines for same power output