4

# Reaction turbines are used for

D. Low head and high discharge

4

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

Directly as fan speed

Square of fan speed

Cube of fan speed

Square root of fan speed

4

# The power produced by the reaction turbine is ________ to the head of water.

Directly proportional

Inversely proportional

4th power

None of these

4

2V/(vr - v)

2V/(vr + v)

V/(vr - v)

V/(vr + v)

4

39.2 %

49.2 %

68.8 %

84.8 %

4

High discharge

4

10 r.p.m.

20 r.p.m.

40 r.p.m.

80 r.p.m.

4

# Maximum impulse will be developed in hydraulic ram when

Waste valve closes suddenly

Supply pipe is long

Supply pipe is short

Ram chamber is large

4

# According to fan laws, for the fans having constant wheel diameters, the power demand varies

Directly as fan speed

Square of fan speed

Cube of fan speed

Square root of fan speed

4

# The specific speed of a turbine is the speed of an imaginary turbine, identical with the given turbine, which

Delivers unit discharge under unit head

Delivers unit discharge under unit speed

Develops unit power under unit head

Develops unit power under unit speed

4

Decreases

Increases

Remain same

None of these

4

# 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

Same quantity of liquid

0.75 Q

Q/0.75

1.5 Q

4

0.15 to 0.3

0.4 to 0.5

0.6 to 0.9

1 to 1.5

4

0.25 kW

0.75 kW

1.75 kW

3.75 kW

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

39.2 %

48.8 %

84.8 %

88.4 %

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

# Which of the following pump is suitable for small discharge and high heads?

Centrifugal pump

Axial flow pump

Mixed flow pump

Reciprocating pump

4

# Multistage centrifugal pumps are used to

Give high discharge

Pump viscous fluids

All of these

4

# Which type of the pump is different from others in the same group?

Screw pump

Gear pump

Cam and piston pump

Plunger pump

4

# The working of which of the following hydraulic units is based on Pascal's law?

Air lift pump

Jet pump

Hydraulic coupling

Hydraulic press

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

# Medium specific speed of turbine implies it is

Propeller turbine

Francis turbine

Impulse turbine

Any one of the above

4

# The runaway speed of a hydraulic turbine is the speed

At which there will be no damage to the runner

At which the turbine will run freely without load

4

# Air vessels in reciprocating pump are used to

Smoothen flow

Reduce acceleration to minimum

Increase pump efficiency

Save pump from cavitations

4

24.8 r.p.m.

48.2 r.p.m

82.4 r.p.m.

248 r.p.m

4

# The flow ratio of Francis turbine is defined as the ratio of the

Velocity of flow at inlet to the theoretical jet velocity

Theoretical velocity of jet to the velocity of flow at inlet

Velocity of runner at inlet to the velocity of flow at inlet

None of the above

4

Strain

Pressure

Kinetic

None of these

4

waV/2g × sinθ

waV/g × sinθ

waV²/2g × sin2θ

waV²/g × sinθ

4

Q/√H

Q/H

Q/H3/2

Q/H²