With increase in ___________________ Knocking tendency in a spark ignition petrol engine decreases?

Related Mcqs:

1. Air-petrol ratio for maximum power generation in spark ignition engine is about_____________________?

   A. 6 : 1
   B. 12 : 1
   C. 18 : 1
   D. 24 : 1

2. The following heat engine produces power of 100,000 kW. The heat engine operates between 800 K and 300 K. It has a thermal efficiency equal to 50% of that of the Carnot engine for the same temperature. The rate at which heat is absorbed from the hot reservoir is____________________?

   A. 100,000 kW
   B. 160,000 kW
   C. 200,000 kW
   D. 320,000 kW

3. The efficiency of an Otto engine compared to that of a diesel engine, for the same compression ratio will be _______________?

   A. More
   B. Less
   C. Same
   D. Data insufficient to predict

4. Which of the following decreases with increase in pressure ?

   A. Melting point of ice
   B. Melting point of wax
   C. Boiling point of liquids
   D. None of these

5. Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about ____________ decibels?

   A. 3
   B. 30
   C. 7
   D. 70

6. Which of the following is normally not found in both the S.I. (petrol) & C.I. (diesel) engines ?

   A. Air filter
   B. Fuel injector
   C. Exhaust silencer
   D. Battery

7. Lead exhausted in the atmosphere by automobiles using leaded petrol (i.e. tetraethyl lead for improving octane number) is a lethal air pollutant which causes_________________?

   A. Paralysis of muscles & loss of appetite
   B. Nervous depression
   C. Gastritis and diarrhea
   D. All A., B. and C.

8. Inhalation of lead compounds present in the automobile exhausts (using leaded petrol) causes________________?

   A. Blood poisoning
   B. Anaemia
   C. Nervous system disorder
   D. All A., B. and C.

9. In any spontaneous process, the ______________ free energy decreases ?

   A. Helmholtz
   B. Gibbs
   C. Both A. & B.
   D. Neither A. nor B.

10. When a gas in a vessel expands, its internal energy decreases. The process involved is________________?

    A. Reversible
    B. Irreversible
    C. Isothermal
    D. Adiabatic