For speed above 3000 km/hour, it is more advantageous to use____________________?

Related Mcqs:

1. Isothermal compression efficiency, even when running at high speed, can be approached by using A. multi-stage compression B. cold water spray C. both A. and B. above D. fully insulating the cylinder E. high stroke_________________?

   Isothermal compression efficiency, even when running at high speed, can be approached by using
   A. multi-stage compression
   B. cold water spray
   C. both A. and B. above
   D. fully insulating the cylinder
   E. high stroke

2. For slow-speed large capacity compressor, following type of valve will be best suited________________?

   A. poppet valve
   B. mechanical valve of the corliss, sleeve, rotary or semirotary type
   C. disc or feather type
   D. any of the above
   E. none of the above

3. The maximum propulsion efficiency of a turbojet is attained at around following speed __________________?

   A. 550 km/hr
   B. 1050km/hr
   C. 1700 km/hr
   D. 2400km /hr
   E. 4000 km/hr

4. Isothermal compression effeicency can be attained by running the compressor__________________?

   A. at very high speed
   B. at very slow speed
   C. at average speed
   D. at zero speed
   E. isothermally

5. What will be the volume of air at 327°C if its volume at 27°C is 1.5 m3/mt ?

   A. 3 m3/mt
   B. 1.5 m3/mt
   C. 18 m3/mt
   D. 6 m3/mt
   E. 0.75 m3/mt

6. Euler’s equation is applicable for__________________?

   A. centrifugal compressor
   B. axial compressor
   C. pumps
   D. all of the above
   E. none of the above

7. During peak load periods, the best method of controlling compressors is___________________?

   A. start-stop motor
   B. constant speed unloader
   C. relief valve
   D. variable speed
   E. none of the above

8. As the value of index ‘«’ is decreased, the volumetric efficiency will___________________?

   A. increase
   B. decrease
   C. remain unaffected
   D. may increase/decrease depending on compressor clearance
   E. none of the above

9. Rotary compressors are suitable for ____________________?

   A. large discharge at high pressure
   B. low discharge at high pressure
   C. large discharge at low pressure
   D. low discharge at low pressure
   E. there is no such limitation

10. High air-fuel ratio is used in gas turbines______________________?

    A. to increase the output
    B. to increase the efficiency
    C. to save fuel
    D. to reduce the exit temperature
    E. none of the above