Hydraulic Machines MCQ Questions and Answers for Practice

1. Maximum impulse will be developed in hydraulic ram when

1. waste valve closes suddenly
2. supply pipe is long
3. supply pipe is short
4. ram chamber is large

2. A hydraulic accumulator normally consists of

1. two cylinders, two rams and a storage device
2. a cylinder and a ram
3. two co-axial rams and two cylinders
4. a cylinder, a piston, storage tank and control valve

3. A hydraulic intensifier normally consists of

1. two cylinders, two rams and a storage device
2. a cylinder and a ram
3. two co-axial rams and two cylinders
4. a cylinder, a piston, storage tank and control valve

4. In reaction turbine, draft tube is used

1. to transport water downstream without eddies
2. to convert the kinetic energy to flow energy by a gradual expansion of the flow cross-section
3. for safety of turbine
4. to increase flow rate

5. The efficiency of a centrifugal pump is maximum when its blades are

1. straight
2. bent forward
3. bent backward
4. bent forward first and then backward

6. In centrifugal pumps, maximum efficiency is obtained when the blades are

1. straight
2. bent forward
3. bent backward
4. radial

7. Motion of a liquid in a volute casing of a centrifugal pump is an example of

1. spiral vortex flow.
2. radial
3. forced spiral vortex flow
4. forced cylindrical vortex flow

8. Air vessels in reciprocating pump are used to

1. smoothen flow
2. reduce acceleration to minimum
3. increase pump efficiency
4. save pump from cavitation

9. If a pump is handling water and is discharging a certain flow Q at a constant total dynamic head requiring a definite B.H.P., the same pump when handling a liquid of specific gravity 0.75 and viscosity nearly same as of water would discharge

1. same quantity of liquid
2. 0.75 Q
3. Q/0.75
4. 1.5 Q

10. The horse power required in above case will be

1. same
2. 0.75 B.H.P.
3. B.H.P./0.75
4. 1.5 B.H.P.

11. In a reciprocating pump, air vessels are used to

1. Reduce the flow
2. Increase the delivery head
3. Smoothen the flow
4. Reduce the acceleration head

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

1. rectilinear flow
2. radial flow
3. free vortex motion
4. forced vortex

13. Pressure intensifier increases the pressure in proportion to

1. ratio of diameters
2. square of ratio of diameters
3. inverse ratio of diameters
4. square of inverse ratio of diameters

14. In axial flow fans and turbines, fluid enters and leaves as follows

1. radially, axially
2. axially, radially
3. axially, axially
4. radially, radially

15. In a centrifugal pump casing, the flow of water leaving the

1. radial
2. radial
3. centrifugal
4. vortex