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

C. Inversely as density

4

0.50 to 0.65

0.65 to 0.75

0.75 to 0.85

0.85 to 0.90

4

# The hydraulic efficiency of a reaction turbine, is the ratio of

Power produced by the turbine to the energy actually supplied by the turbine

Actual work available at the turbine to energy imparted to the wheel

Workdone on the wheel to the energy (or head of water) actually supplied to the turbine

None of the above

4

Pelton wheel

Kaplan turbine

Francis turbine

None of these

4

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

Directly proportional

Inversely proportional

4th power

None of these

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 jet ratio is defined as the ratio of the

Diameter of jet to the diameter of Pelton wheel

Velocity of jet to the velocity of Pelton wheel

Diameter of Pelton wheel to the diameter of jet

Velocity of Pelton wheel to the velocity of jet

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 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

102 watts

75 watts

550 watts

735 watts

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

Hydraulic

Mechanical

Overall

None of these

4

# A hydraulic accumulator 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

# A hydraulic coupling belongs to the category of

Power absorbing machines

Power developing machines

Energy transfer machines

Energy generating machines

4

# Puck up the wrong statement about centrifugal pump

Discharge a diameter

Power a speed⁴

4

0.15 to 0.3

0.4 to 0.5

0.6 to 0.9

1 to 1.5

4

# Which of the following statement is correct?

The centrifugal pump is suitable for large discharge and smaller heads.

The centrifugal pump requires less floor area and simple foundation as compared to reciprocating pump.

The efficiency of centrifugal pump is less as compared to reciprocating pump.

All of the above

4

Product

Difference

Sum

None of these

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

# The function of guide vanes in a reaction turbine is to

Allow the water to enter the runner without shock

Allow the water to flow over them, without forming eddies

Allow the required quantity of water to enter the turbine

All of the above

4

# Slip of a reciprocating pump is defined as the

Ratio of actual discharge to the theoretical discharge

Sum of actual discharge and the theoretical discharge

Difference of theoretical discharge and the actual discharge

Product of theoretical discharge and the actual discharge

4

# Discharge of a centrifugal pump is

Directly proportional to diameter of its impeller

Inversely proportional to diameter of its impeller

Directly proportional to (diameter)² of its impeller

Inversely proportional to (diameter)² of its impeller

4

# Medium specific speed of turbine implies it is

Propeller turbine

Francis turbine

Impulse turbine

Any one of the above

4

10 r.p.m.

20 r.p.m.

40 r.p.m.

80 r.p.m.

4

# Centrifugal pump is started with its delivery valve

Kept fully closed

Kept fully open

Irrespective of any position

Kept 50% open

4

# The undershot water wheels are those in which

The wheel runs entirely by the weight of water

The wheel runs entirely by the impulse of water

The wheel runs partly by the weight of water and partly by the impulse of water

None of the above

4

0.26

0.36

0.46

0.56

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

0.25 m3/s

0.5 m3/s

1.5 m3/s

2.5 m3/s

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