4

4

6

8

12

B. 6

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

# Pressure intensifier increases the pressure in proportion to

Ratio of diameters

Square of ratio of diameters

Inverse ratio of diameters

Square of inverse ratio of diameters

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

2 to 4

4 to 8

8 to 16

16 to 24

4

# The centrifugal pump preferred for a specific speed between 80 to 160 r.p.m. is

Slow speed with radial flow at outlet

Medium speed with radial flow at outlet

High speed with radial flow at outlet

High speed with mixed flow at outlet

4

An axial flow

An inward flow

An outward flow

A mixed flow

4

At the top

At the bottom

At the canter

From sides

4

# According to fan laws, for fans having constant wheel diameter, the air or gas capacity varies

Directly as fan speed

Square of fan speed

Cube of fan speed

Square root of fan speed

4

Strain

Pressure

Kinetic

None of these

4

Centrifugal

Axial flow

Mixed flow

Reciprocating

4

# The flow rate in gear pump

Increases with increase in pressure

Decreases with increase in pressure

More or less remains constant with increase in pressure

Unpredictable

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

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

Centrifugal pump

Axial flow pump

Mixed flow pump

Reciprocating pump

4

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

Directly as the air or gas density

Inversely as square root of density

Inversely as density

As square of density

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

# Multistage centrifugal pumps are used to obtain

High discharge

Pumping of viscous fluids

4

102 watts

75 watts

550 watts

735 watts

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

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

# 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

# Head developed by a centrifugal pump depends on

Impeller diameter

Speed

Fluid density

Both (A) and (B) above

4

39.2 %

48.8 %

84.8 %

88.4 %

4

ηh = ηo × ηm

ηm = ηm × ηh

ηo = ηh × ηm

None of these

4

# Low specific speed of turbine implies it is

Propeller turbine

Francis turbine

Impulse turbine

Any one of the above

4

# A hydraulic coupling belongs to the category of

Power absorbing machines

Power developing machines

Energy transfer machines

Energy generating machines

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

# 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