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.

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

4

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

Rectilinear flow

Free vortex motion

Forced vortex

4

39.2 %

49.2 %

68.8 %

84.8 %

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

4

L.A.N

2 L.A.N

(L.A.N)/60

(2 L.A.N)/60

4

# According to fan laws, at constant speed and capacity, the pressure and power vary

Directly as the air or gas density

Inversely as square root of density

Inversely as density

As square of density

4

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

Directly as the air or gas density

Inversely as square root of density

Inversely as density

As square of density

4

# In order to avoid cavitation in centrifugal pumps

The suction pressure should be high

The delivery pressure should be high

The suction pressure should be low

The delivery pressure should be low

4

# Mechanical efficiency of a centrifugal pump is the ratio of

Energy available at the impeller to the energy supplied to the pump by the prime mover

Actual workdone by the pump to the energy supplied to the pump by the prime mover

Energy supplied to the pump to the energy available at the impeller

Manometric head to the energy supplied by the impeller per kN of water

4

4

# Runaway speed of a hydraulic turbine is

The speed at which turbine runner will be damaged

The speed if the turbine runner is allowed to revolve freely without load and with the wicket gates wide open

The speed corresponding to maximum overload permissible

4

Centrifugal

Axial flow

Mixed flow

Reciprocating

4

Double

Three times

Four times

Five times

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

N/√H

N/H

N/H3/2

N/H²

4

2 to 4

4 to 8

8 to 16

16 to 24

4

0.26

0.36

0.46

0.56

4

Pelton wheel

Kaplan turbine

Francis turbine

None of these

4

# Braking jet in an impulse turbine is used

To break the jet of water

To bring the runner to rest in a short time

To change the direction of runner

None of these

4

# In an outward 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

# The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by

[2(Vr - v) v]/ Vr²

2(Vr + v) v]/ Vr²

[(Vr - v) v]/ Vr

[(Vr + v) v]/ Vr

4

# When a piping system is made up primarily of vertical lift and very little pipe friction, the pump characteristics should be

Horizontal

Nearly horizontal

Steep

First rise and then fall

4

Volute casing

Vortex casing

Any one of these

4

Normal speed

Unit speed

Specific speed

None of these

4

# Puck up the wrong statement about centrifugal pump

Discharge a diameter

Power a speed⁴

4

39.2 %

48.8 %

84.8 %

88.4 %

4

Sum

Difference

Product

None of these

4

Same

0.75 B.H.P.

B.H.P./0.75

1.5 B.H.P.

4

# Dynamic 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

None of the above

4

# When a piping system is made up primarily of friction head and very little of vertical lift, then pump characteristics should be

Horizontal

Nearly horizontal

Steep

First rise and then fall