  # Turbo Machines MCQs with answers - Part 7

This sets of MCQ's contains objective on turbo machines with answers for preparation of your exams in part 7....

## SET 1 of turbo machines mcqs

Q.no 1. The gross or total head of the turbine is the ___________ of the water levels at the head race and tail race
A : Sum
B : Difference
C : Product
D : None of these

Q.no 2. In an outward radial flow turbine energy conversion process is
A : purely by reaction only
B : purely by impulse only
C : partly by impulse and partly by reaction
D : None of these.

Q.no 3. In a velocity triangle at outlet, if angle β is 90 degrees , then Vw2= _________
A : zero
B : more than zero
C : less than zero
D : none

Q.no 4. An impulse turbine is used for
A : Low head of water
B : High head of water
C : Medium head of water
D : High discharge

Q.no 5. 1 Newton force is Equivalent to
A : 10 dyne
B : 100 dyne
C : 1000 dyne
D : None of these

Q.no 6. A Pelton wheel is
A : Tangential flow impulse turbine
B : Inward flow impulse turbine
C : Outward flow impulse turbine
D : Inward flow reaction turbine

Answer:-A : Tangential flow impulse turbine

Q.no 7. Which of the following turbines is most efficient at partload operation?
A : Kaplan turbine
B : Propeller
C : Francis turbine
D : Pelton wheel

Q.no 8. In a francis turbine the gross head on the turbine is 170 m. net head is 110 m. Determine head lost due friction.
A : 60 m
B : 16.2 m
C : 23.4 m
D : 135.6 m

Q.no 9. workdone per second in case of jet of water striking on a moving vertical plate is ________
A : Fx .u
B : Fx.u/2
C : Fx. V
D : zero

Q.no 10. The impulse force is obtained by
A : Newton's I law of motion
B : Newton's II law of motion
C : Newton's III law of motion
D : Newton's law of Viscosity

Answer:-B : Newton's II law of motion

## SET 2 of turbo machines mcqs

Q.no 11. The equation F. dt = d (mv) is called as
A : Impulse momentum equation
B : Impulse reaction principle
C : Newton’s second law of motion.
D : None of these

Q.no 12. Which of the following statement is correct?
A :  In an impulse turbine, the water impinges on the bucket with pressure energy.
B : In a reaction turbine, the water glides over the moving vanes with kinetic energy.
C : In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure
D : In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.

Answer:-C : In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure

Q.no 13. The relation between hydraulic efficiency (ηh), mechanical efficiency (ηm) and overall efficiency (ηo) is
A : ηh = ηo×η
B : ηm = ηo×ηh
C : ηo = ηh×ηm
D : None of these

Q.no 14. The runner passages of a reaction turbine are
A : partially filled with water
B : always completely filled with water
C : never filled with water
D : None of these.

Answer:-B : always completely filled with water

Q.no 15. Governing mechanism used in case of Pelton wheel turbine is ________
A : Guide vane
B : Nozzle & Spear
C : Control valve
D : Dam gates

Q.no 16. In a velocity triangle absolute velocity at inlet V1 has two components, Vf1 and ________
A : Vf2
B : Vw1
C : Vw2
D : Vri

Q.no 17. Francis turbine is
A : A reaction radial flow turbine
B : An axial flow turbine
C : A radial flow turbine
D : An impulse turbine

Q.no 18. A hydraulic turbine converts the potential energy of water into
A : Kinetic energy
B : Heat energy
C : Thermal energy
D : Gravitational energy

Q.no 19. What is the formula for the velocity of water jet at the inlet of turbine? Where, H = Net head acting on Pelton wheel, and Cv = coefficient of velocity of jet
A :  V = Cv √gH
B : V = 2 Cv √gH
C : V = Cv √2gH
D : V = 2 Cv g √H

Q.no 20. In force exerted by jet on series of moving curves vanes, jet strikes tangentially, angle ϴ is called____________
A : guide vane angle at inlet
B : moving vane angle at inlet
C : angle made by jet and inlet tip
D : moving vane angle at exit

Answer:-B : moving vane angle at inlet

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