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.

D. A Francis turbine is an impulse turbine.

4

# A hydraulic press is a device used

To store pressure energy which may be supplied to a machine later on

To increase the intensity of pressure of water by means of energy available from a large quantity of water at a low pressure

To lift larger load by the application of a comparatively much smaller force

All of the above

4

Centrifugal

Axial flow

Mixed flow

Reciprocating

4

0.50 to 0.65

0.65 to 0.75

0.75 to 0.85

0.85 to 0.90

4

102 watts

75 watts

550 watts

735 watts

4

Two

Four

Six

Eight

4

Same

0.75 B.H.P.

B.H.P./0.75

1.5 B.H.P.

4

Q = π.D.Vf

Q = π.b.Vf

Q = π.D.bf.V

Q = D.b.Vf

4

# The discharge through a turbine is

Directly proportional to H1/2

Inversely proportional to H1/2

Directly proportional to H3/2

Inversely proportional to H3/2

4

(D/2d) + 5

(D/2d) + 10

(D/2d) + 15

(D/2d) + 20

4

# Which of the following statement is correct as regard to water wheels?

They have slow speeds

They are suitable even for low water heads

They give constant efficiency, even if the discharge is not constant

All of the above

4

4

6

8

12

4

(1 + cos φ)/2

(1 - cos φ)/2

(1 + sin φ)/2

(1 - sin φ)/2

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

# The discharge through a reaction turbine with increase in unit speed

Increases

Decreases

Remain unaffected

First increases and then decreases

4

# High specific speed of a pump implies it is

Centrifugal pump

Mixed flow pump

Axial flow pump

Any one of the above

4

# A ship with jet propulsion draws water through inlet orifices at right angles to the direction of its motion. The propelling force of the jet is (where a = Area of the jet, Vr = Relative velocity of the jet and ship = V + v, v = Velocity of the ship, and V = Velocity of the jet issuing from the ship)

waVr /g × (Vr + v)

waVr /g × (Vr - v)

waVr /g × (Vr + v)²

waVr /g × (Vr - v)²

4

24.8 r.p.m.

48.2 r.p.m

82.4 r.p.m.

248 r.p.m

4

# Which place in hydraulic turbine is most susceptible for cavitations?

Inlet of draft rube

Penstock

4

Axially, axially

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

0 to 4.5

10 to 100

80 to 200

250 to 300

4

P/ √H

P/ H

P/ H3/2

P/ H²

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

ηh = ηo × ηm

ηm = ηm × ηh

ηo = ηh × ηm

None of these

4

# The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by

[2(Vr - v) v]/ Vr²

2(Vr + v) v]/ Vr²

[(Vr - v) v]/ Vr

[(Vr + v) v]/ Vr

4

One-fourth

One-half

Three-fourth

Double

4

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

Directly proportional

Inversely proportional

4th power

None of these

4

Greater than 15°

Greater than 8°

Greater than 5°

Less than 8°

4

# Which of the following statement is correct?

In an impulse turbine, the water impinges on the buckets with pressure energy.

In a reaction turbine, the water glides over the moving vanes with kinetic energy.

In an impulse turbine, the pressure of the flowing water remains unchanged and is equal to atmospheric pressure.

In a reaction turbine, the pressure of the flowing water increases after gliding over the vanes.