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

D. At which the turbine will run freely without load

4

(D/2d) + 5

(D/2d) + 10

(D/2d) + 15

(D/2d) + 20

4

4

6

8

12

4

2V/(vr - v)

2V/(vr + v)

V/(vr - v)

V/(vr + v)

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

Normal speed

Unit speed

Specific speed

None of these

4

(1 + cos φ)/2

(1 - cos φ)/2

(1 + sin φ)/2

(1 - sin φ)/2

4

# A turbine is required to develop 1500 kW at 300 r.p.m. under a head of 150 m. Which of the following turbine should be used?

Pelton wheel with one nozzle

Pelton wheel with two or more nozzles

Kaplan turbine

Francis turbine

4

N√P / H3/2

N√P / H²

N√P / H5/4

N√P / H3

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

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

Rectilinear flow

Free vortex motion

Forced vortex

4

Volute casing

Vortex casing

Any one of these

4

# High specific speed of a pump implies it is

Centrifugal pump

Mixed flow pump

Axial flow pump

Any one of the above

4

1/√2

1/2

1

√2

4

An axial flow

An inward flow

An outward flow

A mixed flow

4

# Head developed by a centrifugal pump is

Proportional to diameter of impeller

Proportional to speed of impeller

Proportional to diameter and speed of impeller

None of the above

4

# In a reciprocating pump, air vessels are used to

Smoothen the flow

4

waV/2g × sinθ

waV/g × sinθ

waV²/2g × sin2θ

waV²/g × sinθ

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

# The specific speed of turbine is defined as the speed of a unit

Of such a size that it delivers unit discharge at unit head

Of such a size that it delivers unit discharge at unit power

Of such a size that it requires unit power per unit head

Of such a size that it produces unit horse power with unit head

4

2 to 4

4 to 8

8 to 16

16 to 24

4

# The hydraulic efficiency of an impulse turbine is the

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

# Delivery head of a centrifugal pump is

Directly proportional to N

Inversely proportional to N

Directly proportional to N²

Inversely proportional to N²

4

# Slip of a reciprocating pump is negative, when

Suction pipe is short and pump is running at low speeds

Delivery pipe is long and pump is running at high speeds

Suction pipe is short and delivery pipe is long and the pump is running at low speeds

Suction pipe is long and delivery pipe is short and the pump is running at high speeds

4

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

Directly as the air or gas density

Inversely as square root of density

Inversely as density

As square of density

4

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

Impulse turbines

Reaction turbines

Axial flow turbines

Mixed flow turbines

4

0 to 25 m

25 m to 250 m

Above 250 m

None of these

4

Two

Four

Six

Eight

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

ηh = ηo × ηm

ηm = ηm × ηh

ηo = ηh × ηm

None of these