# Turbo Machines Test Questions Set - 1

1)   The product of force (F) and time (t) is called as________.

a. momentum
b. work done
c. impulse
d. pressure
 Answer  Explanation  Related Ques ANSWER: impulse Explanation: No explanation is available for this question!

2)   What is the formula for forces exerted by fluid on a body?

a. (Rate of momentum in) x (Rate of momentum out)
b. (Rate of momentum in) – (Rate of momentum out)
c. (Rate of momentum in) + (Rate of momentum out)
d. None of the above
 Answer  Explanation  Related Ques ANSWER: (Rate of momentum in) – (Rate of momentum out) Explanation: No explanation is available for this question!

3)   The radial force in rotodynamic machine, which is developed by rate of change of momentum in radial velocity, is taken care by__________.

a. journal bearing
c. both a. and b.
d. none of the above
 Answer  Explanation  Related Ques ANSWER: journal bearing Explanation: No explanation is available for this question!

4)   Meridonial velocity is the resultant of _____________ components of fluid velocity.

b. tangential and axial
d. unpredictable

5)   _______________ components of fluid velocity have the responsibility of the transportation of fluid through the machine.

b. Tangential and axial
d. None of the existing

6)   In which turbine the pressure energy of water is first converted into kinetic energy by means of nozzle kept close to the runner?

a. Impulse turbine
b. Reaction turbine
c. Both a. and b.
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Impulse turbine Explanation: No explanation is available for this question!

7)   The pressure of water is atmospheric and remains constant while passing over the runner in __________ .

a. Impulse turbine
b. Reaction turbine
c. Both a. and b.
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Impulse turbine Explanation: No explanation is available for this question!

8)   The energy of water entering the reaction turbine is _______

a. fully the kinetic energy
b. fully the pressure energy
c. partly the pressure energy and partly the kinetic energy
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: partly the pressure energy and partly the kinetic energy Explanation: No explanation is available for this question!

9)   Which of the following is an example of impulse turbine?

a. Propeller turbine
b. Francis turbine
c. Kaplan turbine
d. Pelton wheel
 Answer  Explanation  Related Ques ANSWER: Pelton wheel Explanation: No explanation is available for this question!

10)   The runner of __________ turbine always be under pressure of above atmospheric

a. Turgo
b. Girand
c. Kaplan
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Kaplan Explanation: No explanation is available for this question!

11)   The water from runner in reaction turbine is discharged into tail race through a draft tube which has ____________ cross sectional area.

a. constant
d. uneven

12)   __________ turbines are also called as parallel flow turbine.

b. Axial flow
c. Both radial flow and axial flow
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Axial flow Explanation: No explanation is available for this question!

13)   In which type of reaction turbine does the water flow in radial direction at the outer periphery of runner and leave at the centre in the direction parallel to the axis of rotation of runner?

b. Axial flow turbine
c. Mixed flow turbine
d. All of the above
 Answer  Explanation  Related Ques ANSWER: Mixed flow turbine Explanation: No explanation is available for this question!

14)   What is the formula to calculate specific speed (Ns) of a turbine rotating at a speed of 'N' rpm that develops the power of 'P' kW at the heat of 'H' m?

a. (Ns) = (√N x P) x (H)(5/4)
b. (Ns) = (2 √N x P) x (H)(5/4)
c. (Ns) = (N √P) x (H)(5/4)
d. (Ns) = (2N √P) x (H)(5/4)
 Answer  Explanation  Related Ques ANSWER: (Ns) = (N √P) x (H)(5/4) Explanation: No explanation is available for this question!

15)   Generally, the value of specific speed of Kaplan turbine is _____________ that of the Pelton turbine.

a. lower than
b. higher than
c. same as
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: higher than Explanation: No explanation is available for this question!

16)   The passage of uniformly varying cross-section in which the kinetic energy of steam increases at the expense of its pressure is called as__________

a. steam turbine
b. steam nozzle
c. steam area
d. all of the above
 Answer  Explanation  Related Ques ANSWER: steam nozzle Explanation: No explanation is available for this question!

17)   How does the change in velocity of the steam in steam nozzle take place? Select the correct graph in the diagram below. a. (1)
b. (2)
c. (3)
d. (4)
 Answer  Explanation  Related Ques ANSWER: (3) Explanation: No explanation is available for this question!

18)   The nozzle efficiency can be defined as the ratio of

a. isentropic enthalpy drop to actual enthalpy drop
b. actual enthalpy drop to isentropic enthalpy drop
c. isothermal enthalpy drop to isentropic enthalpy drop
d. isentropic enthalpy drop to isothermal enthalpy drop
 Answer  Explanation  Related Ques ANSWER: actual enthalpy drop to isentropic enthalpy drop Explanation: No explanation is available for this question!

19)   Which of the following are effects of nozzle friction?

1. Enthalpy drop decreases
2. Exit velocity reduces
3. Decrease in specific volume
4. Decrease in mass flow rate

a. (1), (2) and (3)
b. (2), (3) and (4)
c. (1), (3) and (4)
d. (1), (2) and (4)
 Answer  Explanation  Related Ques ANSWER: (1), (2) and (4) Explanation: No explanation is available for this question!

20)   The quality of vapour at the exit of nozzle ___________ due to nozzle friction.

a. increases
b. decreases
c. does not change
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: increases Explanation: No explanation is available for this question!

21)   Pump transfers the mechanical energy of a motor or of an engine into _________ of a fluid.

a. pressure energy
b. kinetic energy
c. either pressure energy or kinetic energy
d. pressure energy, kinetic energy or both
 Answer  Explanation  Related Ques ANSWER: pressure energy, kinetic energy or both Explanation: No explanation is available for this question!

22)   Which of the following is NOT a type of positive displacement pumps?

a. Reciprocating pump
b. Rotary displacement pump
c. Centrifugal pump
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Centrifugal pump Explanation: No explanation is available for this question!

23)   Rotary displacement pumps are suitable for handling ________.

a. oils
b. gritty liquids
c. both oils as well as gritty liquids
d. None of the above
 Answer  Explanation  Related Ques ANSWER: oils Explanation: No explanation is available for this question!

24)   Which of the following is/are example/s of rotary displacement pumps?

a. Gear pump
b. Vane pump
c. Rotary piston pump
d. All of the above
 Answer  Explanation  Related Ques ANSWER: All of the above Explanation: No explanation is available for this question!

25)   ___________ pump is also called as velocity pump.

a. Reciprocating
b. Rotary displacement
c. Centrifugal
d. Screw
 Answer  Explanation  Related Ques ANSWER: Centrifugal Explanation: No explanation is available for this question!

26)   The mass flow rate of air compressed in axial flow compressor is _____________centrifugal compressor.

a. lower than
b. higher than
c. same as
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: higher than Explanation: No explanation is available for this question!

27)   Which of the following is NOT a type of rotary compressor?

a. Positive displacement type of compressor
c. Both a. and b.
d. None of the above
 Answer  Explanation  Related Ques ANSWER: None of the above Explanation: No explanation is available for this question!

28)   Which compressors are suitable for large volume flow rates of above 1200 m3/min

a. Centrifugal compressors
b. Axial flow compressors
c. Both a. and b.
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Axial flow compressors Explanation: No explanation is available for this question!

29)   The function of _________ is to convert high kinetic energy of gases into pressure energy.

a. impeller
b. diffuser
c. casing
d. None of the above
 Answer  Explanation  Related Ques ANSWER: diffuser Explanation: No explanation is available for this question!

30)   How is the variation of air velocity while passing through impeller followed by diffuser in centrifugal compressor?

a. Air velocity goes no increasing in impeller followed by diffuser
b. Air velocity goes no decreasing in impeller followed by diffuser
c. Air velocity increases in impeller and then decreases in diffuser
d. Air velocity decreases in impeller and then increases in diffuser
 Answer  Explanation  Related Ques ANSWER: Air velocity increases in impeller and then decreases in diffuser Explanation: No explanation is available for this question!

31)   A pair of fixed blade and rotor blade in axial flow compressor is called as _________.

a. step
b. pair
c. stage
d. state
 Answer  Explanation  Related Ques ANSWER: stage Explanation: No explanation is available for this question!

32)   An axial flow compressors have _______.

a. a drum type rotor
b. a disc type rotor
c. a drum type rotor or a disc type rotor
d. none of the above
 Answer  Explanation  Related Ques ANSWER: a drum type rotor or a disc type rotor Explanation: No explanation is available for this question!

33)   ________ blades are attached to the rotor or spindle.

a. Fixed
b. Moving
c. Both fixed and moving
d. None of the above
 Answer  Explanation  Related Ques ANSWER: Moving Explanation: No explanation is available for this question!

34)   The basic principle of operation of axial flow compressor is _______that of the centrifugal compressor.

a. same as
b. totally different than

 Answer  Explanation  Related Ques ANSWER: same as Explanation: No explanation is available for this question!

35)   The blade passages in a compressor are ________

a. converging
b. diverging
c. constant
d. unpredictable
 Answer  Explanation  Related Ques ANSWER: diverging Explanation: No explanation is available for this question!