4

In a reciprocating pump, air vessels are used to

Smoothen the flow

4

(W/p) × (A/a)

(p/W) × (a/A)

(W/p) × (a/A)

(p/W) × (A/a)

4

Which of the following statement is wrong?

The reaction turbines are used for low head and high discharge.

The angle of taper on draft tube is less than 8°.

An impulse turbine is generally fitted slightly above the tail race.

A Francis turbine is an impulse turbine.

4

4

6

8

12

4

Straight

Bent forward

Bent backward

4

Axially, axially

4

Low specific speed of turbine implies it is

Propeller turbine

Francis turbine

Impulse turbine

Any one of the above

4

Which of the following pump is generally used to pump highly viscous fluid?

Centrifugal pump

Reciprocating pump

Air lift pump

Screw pump

4

Impulse turbine is generally fitted

At the level of tail race

Little above the tail race

Slightly below the tail race

About 2.5 m above the tail race to avoid cavitations.

4

N/√H

N/H

N/H3/2

N/H²

4

A turbine pump is basically a centrifugal pump equipped additionally with

Vaned diffusion casing

4

Power required (in watts) to drive a centrifugal pump is (where Hm = Manometric head in metres, w = Specific weight in N/m3, Q = Discharge of the pump in m3/s, and ηo = Overall efficiency of the pump)

(w Hm) / (Q × ηo)

(w Hm Q) / ηo

(w Q) / (Hm × ηo)

(w Q ηo) / Hm

4

The cavitation in a hydraulic machine

Causes noise and vibration of various parts

Reduces the discharge of a turbine

Causes sudden drop in power output and efficiency

All of the above

4

Q = π.D.Vf

Q = π.b.Vf

Q = π.D.bf.V

Q = D.b.Vf

4

If the ratios of all the corresponding linear dimensions are equal, then the model and the prototype are said to have

Geometric similarity

Kinematic similarity

Dynamic similarity

None of these

4

Head developed by a centrifugal pump depends on

Impeller diameter

Speed

Fluid density

Both (A) and (B) above

4

High specific speed of turbine implies it is

Propeller turbine

Francis turbine

Impulse turbine

None of the above

4

10-15°

20-25°

30-40°

50-60°

4

The impeller of a centrifugal pump may have

Volute casing

Vortex casing

Any one of these

4

Absolute velocity

Flow

4

Which of the following pump is successfully used for lifting water from deep wells?

Centrifugal pump

Reciprocating pump

Jet pump

Air lift pump

4

Pelton wheel

Francis turbine

Kaplan turbine

None of these

4

Discharge of a centrifugal pump is (where N = Speed of the pump impeller)

Directly proportional to N

Inversely proportional to N

Directly proportional to N²

Inversely proportional to N²

4

The hydraulic efficiency of an impulse turbine is the

Ratio of the actual power produced by the turbine to the energy actually supplied by the turbine

Ratio of the actual work available at the turbine to the energy imparted to the wheel

Ratio of the work done on the wheel to the energy of the jet

None of the above

4

0 to 25 m

25 m to 250 m

Above 250 m

None of these

4

Turgo turbine

Pelton wheel

Kaplan turbine

4

2V/(vr - v)

2V/(vr + v)

V/(vr - v)

V/(vr + v)

4

Low velocity

High velocity

Low pressure

High pressure

4

The type of centrifugal pump preferred for a specific speed of 20 r.p.m. is

Slow speed pump with radial flow at outlet

Medium speed pump with radial flow at outlet

High speed pump with radial flow at outlet

High speed pump with axial flow at outlet

4