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Mechanical Engineering :: Internal Combustion Engines

  1. Engine pistons are usually made of aluminium alloy because it

  2. A.

     Is lighter

    B.

     Wear is less

    C.

     Absorbs shocks

    D.

     Is stronger


  3. The reason for supercharging in any engine is to

  4. A.

     Increase efficiency

    B.

     Increase power

    C.

     Reduce weight and bulk for a given output

    D.

     Effect fuel economy


  5. Morse test can be conducted for

  6. A.

     Petrol engines

    B.

     Diesel engines

    C.

     Multi cylinder engines

    D.

     All of these


  7. The cetane (C₁₆H₃₄) which is a straight chain paraffin, is assigned a cetane number of

  8. A.

     0

    B.

     50

    C.

     100

    D.

     120


  9. Alpha-methyl-naphthalene (C₁₁ H₁₀) has a cetane number of

  10. A.

     0

    B.

     50

    C.

     100

    D.

     120


  11. The scavenging efficiency of a four stroke cycle diesel engine is

  12. A.

     Below 50%

    B.

     Between 50 and 85%

    C.

     Between 85 and 95%

    D.

     Between 95 and 100%


  13. Scavenging is usually done to increase

  14. A.

     Thermal efficiency

    B.

     Speed

    C.

     Power output

    D.

     Fuel consumption


  15. Which of the following medium is compressed in a Diesel engine cylinder?

  16. A.

     Air alone

    B.

     Air and fuel

    C.

     Air and lub oil

    D.

     Fuel alone


  17. Number of working strokes per min. for a four stroke cycle engine are _________ the speed of the engine in r.p.m.

  18. A.

     Equal to

    B.

     One-half

    C.

     Twice

    D.

     Four-times


  19. Number of working strokes per min. for a two stroke cycle engine is _________ the speed of the engine in r.p.m.

  20. A.

     Equal to

    B.

     One-half

    C.

     Twice

    D.

     Four-times