4

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

Rotational flow

Forced spiral vortex flow

Spiral vortex flow

D. Spiral vortex flow

4

# Guide angle as per the aerofoil theory of Kaplan turbine blade design is defined as the angle between

Lift and resultant force

Drag and resultant force

Lift and tangential force

Lift and drag

4

Two jets

Two runners

Four jets

Four runners

4

# A hydraulic intensifier normally consists of

Two cylinders, two rams and a storage device

A cylinder and a ram

Two coaxial rams and two cylinders

A cylinder, a piston, storage tank and control valve

4

# Which of the following pump is successfully used for lifting water to the boilers?

Centrifugal pump

Reciprocating pump

Jet pump

Airlift pump

4

0 to 4.5

10 to 100

80 to 200

250 to 300

4

(1 + cos φ)/2

(1 - cos φ)/2

(1 + sin φ)/2

(1 - sin φ)/2

4

# Head developed by a centrifugal pump depends on

Impeller diameter

Speed

Fluid density

Both (A) and (B) above

4

# In a reciprocating pump, air vessels are used to

Smoothen the flow

4

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

Have identical velocities

Are equal in size and shape

Are identical in shape, but differ only in size

Have identical forces

4

# In an inward flow reaction turbine

The water flows parallel to the axis of the wheel

The water enters at the centre of the wheel and then flows towards the outer periphery of the wheel

The water enters the wheel at the outer periphery and then flows towards the centre of the wheel

The flow of water is partly radial and partly axial

4

# In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by

Designing new impeller

Trimming the impeller size to the required size by machining

Not possible

Some other alterations in the impeller

4

# The discharge through a turbine is

Directly proportional to H1/2

Inversely proportional to H1/2

Directly proportional to H3/2

Inversely proportional to H3/2

4

# Casting of a centrifugal pump is designed so as to minimize

Friction loss

Cavitations

Loss of kinetic energy

4

# Which of the following statement is correct as regard to water wheels?

They have slow speeds

They are suitable even for low water heads

They give constant efficiency, even if the discharge is not constant

All of the above

4

(N√Q)/H2/3

(N√Q)/H3/4

(N√Q)/H

(N√Q)/H5/4

4

4

Remain same

Increases

Decreases

None of these

4

# Manometric head, in case of a centrifugal pump, is equal to

Suction lift + Loss of head in suction pipe due to friction + Delivery lift + Loss of head in delivery pipe due to friction + Velocity head in the delivery pipe

Workdone per kN of water Losses within the impeller

Energy per kN at outlet of impeller Energy per kN at inlet of impeller

All of the above

4

# A ship with jet propulsion draws water through inlet orifices at right angles to the direction of its motion. The propelling force of the jet is (where a = Area of the jet, Vr = Relative velocity of the jet and ship = V + v, v = Velocity of the ship, and V = Velocity of the jet issuing from the ship)

waVr /g × (Vr + v)

waVr /g × (Vr - v)

waVr /g × (Vr + v)²

waVr /g × (Vr - v)²

4

High discharge

4

Straight

Bent forward

Bent backward

4

# The specific speed of turbine is defined as the speed of a unit

Of such a size that it delivers unit discharge at unit head

Of such a size that it delivers unit discharge at unit power

Of such a size that it requires unit power per unit head

Of such a size that it produces unit horse power with unit head

4

Hydraulic

Mechanical

Overall

None of these

4

40 %

50 %

60 %

80 %

4

Potential Energy

Strain Energy

Kinetic energy

None of these

4

# Which of the following statement is correct?

In an impulse turbine, the water impinges on the buckets with pressure energy.

In a reaction turbine, the water glides over the moving vanes with kinetic energy.

In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure.

In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.

4

Sum

Difference

Product

None of these

4

# In a reaction turbine, the draft tube is used

To run the turbine full

To prevent air to enter the turbine

To increase the head of water by an amount equal to the height of the runner outlet above the tail race

To transport water to downstream

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