# Hydraulic Machines-Fluid Machineries – Set 09

Are you guys looking for Mechanical Engineering MCQ Questions with Answers PDF Free Download as per Mechanical Engineering new exam pattern? You came to the right page. This may assist you to understand and check your knowledge about the Subjects. Students also can take a free test of the Multiple Choice Questions of Mechanical Engineering. Each question has four options followed by the right answer. These Mechanical Engineering MCQ Questions are selected supported by the newest exam pattern.

(A) One-fourth
(B) One-half
(C) Three-fourth
(D) Double

## Q2. Which of the following turbine is preferred for 0 to 25 m head of water?

(A) Pelton wheel
(B) Kaplan turbine
(C) Francis turbine
(D) None of these

## Q3. In a centrifugal pump casing, the flow of water leaving the impeller, is

(A) Rectilinear flow
(C) Free vortex motion
(D) Forced vortex

## Q4. In a reaction turbine, the draft tube is used

(A) To run the turbine full
(B) To prevent air to enter the turbine
(C) To increase the head of water by an amount equal to the height of the runner outlet above the tail race
(D) To transport water to downstream

Answer: (C) To increase the head of water by an amount equal to the height of the runner outlet above the tail race

## Q5. The hydraulic efficiency of an impulse turbine is the

(A) Ratio of the actual power produced by the turbine to the energy actually supplied by the turbine
(B) Ratio of the actual work available at the turbine to the energy imparted to the wheel
(C) Ratio of the work done on the wheel to the energy of the jet
(D) None of the above

Answer: (C) Ratio of the work done on the wheel to the energy of the jet

## Q6. According to fan laws, at constant weight of air or gas, the speed, capacity and pressure vary

(A) Directly as the air or gas density
(B) Inversely as square root of density
(C) Inversely as density
(D) As square of density

## Q7. A Francis turbine is used when the available head of water is

(A) 0 to 25 m
(B) 25 m to 250 m
(C) Above 250 m
(D) None of these

Answer: (B) 25 m to 250 m

## Q8. The cavitation in a hydraulic machine

(A) Causes noise and vibration of various parts
(B) Reduces the discharge of a turbine
(C) Causes sudden drop in power output and efficiency
(D) All of the above

Answer: (D) All of the above

## Q9. Maximum impulse will be developed in hydraulic ram when

(A) Waste valve closes suddenly
(B) Supply pipe is long
(C) Supply pipe is short
(D) Ram chamber is large

Answer: (A) Waste valve closes suddenly

## Q10. In reaction turbine, draft tube is used

(A) To transport water downstream without eddies
(B) To convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
(C) For safety of turbine
(D) To increase flow rate

Answer: (B) To convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section

## Q11. According to fan laws, for fans having constant wheel diameter, the pressure varies

(A) Directly as fan speed
(B) Square of fan speed
(C) Cube of fan speed
(D) Square root of fan speed

Answer: (B) Square of fan speed

## Q12. A hydraulic accumulator normally consists of

(A) Two cylinders, two rams and a storage device
(B) A cylinder and a ram
(C) Two coaxial rams and two cylinders
(D) A cylinder, a piston, storage tank and control valve

Answer: (B) A cylinder and a ram

## Q13. A hydraulic intensifier normally consists of

(A) Two cylinders, two rams and a storage device
(B) A cylinder and a ram
(C) Two coaxial rams and two cylinders
(D) A cylinder, a piston, storage tank and control valve

Answer: (C) Two coaxial rams and two cylinders

## Q14. Dynamic similarity is said to exist between the model and the prototype, if both of them

(A) Have identical velocities
(B) Are equal in size and shape
(C) Are identical in shape, but differ only in size
(D) None of the above

Answer: (D) None of the above

## Q15. A hydraulic accumulator is a device used to store _ energy which may be supplied to a machine later on.

(A) Strain
(B) Pressure
(C) Kinetic
(D) None of these

## Q16. Slip of a reciprocating pump is defined as the

(A) Ratio of actual discharge to the theoretical discharge
(B) Sum of actual discharge and the theoretical discharge
(C) Difference of theoretical discharge and the actual discharge
(D) Product of theoretical discharge and the actual discharge

Answer:(C) Difference of theoretical discharge and the actual discharge

(A) 2V/(vr – v)
(B) 2V/(vr + v)
(C) V/(vr – v)
(D) V/(vr + v)

## Q18. In a centrifugal pump, the regulating valve is provided on the

(A) Casing
(B) Delivery pipe
(C) Suction pipe
(D) Impeller

## Q19. For starting an axial flow pump, its delivery valve should be

(A) Closed
(B) Open
(C) Depends on starting condition and flow desired
(D) Could be either open or closed