4

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

Friction loss

Cavitations

Loss of kinetic energy

D. Loss of kinetic energy

4

# Francis, Kaplan and propeller turbines fall under the category of

Impulse turbines

Reaction turbines

Axial flow turbines

Mixed flow turbines

4

(1 + cos φ)/2

(1 - cos φ)/2

(1 + sin φ)/2

(1 - sin φ)/2

4

Two jets

Two runners

Four jets

Four runners

4

# Which of the following pump is successfully used for lifting water from deep wells?

Centrifugal pump

Reciprocating pump

Jet pump

Air lift pump

4

Turgo turbine

Pelton wheel

Kaplan turbine

4

Axial

Centrifugal

Vortex

4

# A Pelton wheel is

Tangential flow impulse turbine

Inward flow impulse turbine

Outward flow impulse turbine

Inward flow reaction turbine

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

# 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

# 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

39.2 %

49.2 %

68.8 %

84.8 %

4

0.26

0.36

0.46

0.56

4

# If the ratio's of the corresponding forces acting at corresponding points are equal, then the model and the prototype are said to have.

Geometric similarity

Kinematic similarity

Dynamic similarity

None of these

4

# For starting an axial flow pump, its delivery valve should be

Closed

Open

Depends on starting condition and flow desired

Could be either open or closed

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

2 to 4

4 to 8

8 to 16

16 to 24

4

4

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

Centrifugal pump

Reciprocating pump

Jet pump

Air lift pump

4

# The speed of a turbine runner is

Directly proportional to H1/2

Inversely proportional to H1/2

Directly proportional to H3/2

Inversely proportional to H3/2

4

N/√H

N/H

N/H3/2

N/H²

4

# The mechanical efficiency of an impulse turbine is

Ratio of the actual power produced by the turbine to the energy actually supplied by the turbine

Ratio of the actual work available at the turbine to the energy imparted to the wheel

Ratio of the Work done on the wheel to the energy of the jet

None of the above

4

Hydraulic

Mechanical

Overall

None of these

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

# 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 cavitation in reaction turbines is avoided, to a great extent by

Installing the turbine below the tail race level

Using stainless steel runner of the turbine

Providing highly polished blades to the runner

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

# Multistage centrifugal pumps are used to obtain

High discharge

Pumping of viscous fluids

4

Pelton wheel

Francis turbine

Kaplan turbine

None of these

4

0 to 4.5

10 to 100

80 to 200

250 to 300