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

C. Difference of theoretical discharge and the actual discharge

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

# 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

10-15°

20-25°

30-40°

50-60°

4

10° to 15°

15° to 20°

20° to 25°

25° to 30°

4

# The overall 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 the 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

# A Pelton wheel is

Tangential flow impulse turbine

Inward flow impulse turbine

Outward flow impulse turbine

Inward flow reaction turbine

4

Equal to

1.2 times

1.8 times

Double

4

Centrifugal

Axial flow

Reciprocating

Mixed flow

4

# A turbine pump is basically a centrifugal pump equipped additionally with

Vaned diffusion casing

4

# A hydraulic intensifier 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

# 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

4

175.4 r.p.m.

215.5 r.p.m.

241.5 r.p.m.

275.4 r.p.m

4

Same

0.75 B.H.P.

B.H.P./0.75

1.5 B.H.P.

4

# Hydraulic accumulator is used for

Accumulating oil

Supplying large quantities of oil for very short duration

Generally high pressures to operate hydraulic machines

Supplying energy when main supply fails

4

0 to 25 m

25 m to 250 m

Above 250 m

None of these

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

0.50 to 0.65

0.65 to 0.75

0.75 to 0.85

0.85 to 0.90

4

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

Rectilinear flow

Free vortex motion

Forced vortex

4

# Francis turbine is best suited for

Medium head application from 24 to 180 m

Low head installation up to 30 m

High head installation above 180 m

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

Axially, axially

4

# If the net positive suction head (NPSH) requirement for the pump is not satisfied, then

No flow will take place

Cavitation will be formed

Efficiency will be low

Excessive power will be consumed

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

One-fourth

One-half

Three-fourth

Double

4

0 to 4.5

10 to 100

80 to 200

250 to 300

4

Greater than 15°

Greater than 8°

Greater than 5°

Less than 8°

4

# In a single casing, multistage pump running at constant speed, the capacity rating is to be slightly lowered. It can be done by

Designing new impeller

Trimming the impeller size to the required size by machining

Not possible

Some other alterations in the impeller

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

# Impulse turbine is generally fitted

At the level of tail race

Little above the tail race

Slightly below the tail race

About 2.5 m above the tail race to avoid cavitations.