The degree of reaction of an axial flow turbine is the ratio of isentropic temperature drop in a blade row to the_____________________?

Related Mcqs:

1. In the axial flow gas turbine, the work ratio is the ratio of____________________?

   A. compressor work and turbine work
   B. output and input
   C. actual total head tempeature drop to the isentrpic total head drop from total head inlet to static head outlet
   D. actual compressor work and theoretical comprssor work
   E. none of the above

2. There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would__________________?

   A. remain same
   B. decrease
   C. increase
   D. unpredictable
   E. none of the above

3. If V, U and Vr represent the absolute velocity of fluid, velocity of blade, and relative velocity of fluid, and suffix i and o stand for entry and exit conditions, then in a rotary machine whose degree of reaction is unity______________?

   A. Vi=V0B
   B. Vt>V0
   C. U,<V0
   D. V,= U0
   E. Vri=Vm

4. The pressure ratio for an open cycle gas turbine compared to closed cycle gas turbine of same h.p. is_______________?

   A. low
   B. high
   C. same
   D. low/high depending on make and type
   E. unpredictable

5. The weight per horse power ratio for gas. turbine as compared to I.C. engine and steam turbine is________________?

   A. same
   B. higher
   C. lower
   D. uncomparable
   E. unpredictable

6. The thermal efficiency of a simple gas turbine for a given turbine inlet temperature with increase in pressure ratio_____________________?

   A. increases
   B. decreases
   C. first increases and then decreases
   D. first decreases and then increases
   E. remains same

7. As the turbine inlet temperature increases, the thermal efficiency of gas turbine for the optimum pressure ratio_____________________?

   A. increases
   B. decreases
   C. remains same
   D. first increases and then decreases
   E. first decreases and then increases

8. The specific output per kg mass flow rate of a gas turbine (having fixed efficiencies of compressor and turine and fixed higher and lower temperature) with increase in pressure ratio will___________________?

   A. increase first at fast rate and then slow
   B. increase first at slow rate and then fast
   C. decrease continuously
   D. first increase, reach maximum and then decrease
   E. none of the above

9. The maximum compression ratio in an actual single stage axial flow comperssor is of the order of________________?

   A. 1 : 1.2
   B. 1 : 2
   C. 1 : 5
   D. 1 : 10
   E. 1 : 1

10. The ratio of outlet whirl velocity to blade velocity in case of centrifugal compressor is called__________________?

    A. slip factor
    B. velocity factor
    C. velocity coefficient
    D. blade effectiveness