The- most efficient method of compressing air is to compress it_________________?

Related Mcqs:

1. Maximum work is done in compressing air when the compression is_________________?

   A. isothermal
   B. adiabatic
   C. polytropic
   D. any one of the above
   E. none of the above

2. Free air is the air at________________?

   A. atmospheric conditions at any specific location
   B. 20°C and 1 kg/cm2 and relative humidity of 36%
   C. 0°C and standard atmospheric conditions
   D. 15°C and 1 kg/cm2
   E. 25°C, 1 kg/cm2 and relative humidity of 50%.

3. Standard air is the air at_____________________?

   A. atmospheric conditions at any specific location
   B. 20°C and 1 kg/cm2 and relative humidity 36%
   C. 0°C and standard atmospheric conditions
   D. 15°C and 1 kg/cm2
   E. 25°C, 1 kg/cm2 and RH of 60%.

4. The specific fuel consumption for a petrol engine first decreases with increase in fuel air ratio and then increases with further increase in fuel air ratio. The minimum value occurs in the range of__________________?

   A. lean mixture
   B. chemically correct mixture
   C. rich mixture
   D. unpredictable
   E. none of the above

5. 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

6. The m.e.p. of a petrol engine first increases as the fuel air ratio is increased and then decreases on further increase in fuel air ratio. The M.E.P is maximum in the zone of________________?

   A. lean mixture
   B. chemically correct mixture
   C. rich mixture
   D. unpredictable
   E. none of the above

7. Primary air is the air used to__________________?

   A. provide air around burners for obtaining optimum combustion
   B. transport and dry the coal
   C. convert CO (formed in lower zone of furnace) into C02 at higher zone
   D. air-delivered by forced draft fan
   E. none ot the above

8. Tertiary air is the air used to____________________?

   A. provide air around burners for obtaining optimum combustion
   B. transport and dry the coal
   C. cool the scanners
   D. supply air for ignitors
   E. convert CO (formed in lower zone of furnace) into C02 at higher zone

9. What is the weight (in lbf) of one gallon of air at 1 atm and 25˚C? The molecular mass of air is 28.97 g/mole = 0.02897 kg/mole

   A. 90 lbf
   B. 65.78 lbf
   C. 0.00989 lbf
   D. 3.00989 lbf

   Submitted by: Faheem Zaman Dhaunroo

10. Isothermal compression though most efficient, but is not -practicable because_________________?

    A. ityrequires very big cylinder
    B. it does not increase pressure much
    C. it is impossible in practice
    D. compressor has to run at very slow speed to achieve it
    E. it requires cylinder to be placed in water