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.

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

Centrifugal

Axial flow

Mixed flow

Reciprocating

0.50 to 0.65

0.65 to 0.75

0.75 to 0.85

0.85 to 0.90

102 watts

75 watts

550 watts

735 watts

Two

Four

Six

Eight

Same

0.75 B.H.P.

B.H.P./0.75

1.5 B.H.P.

Q = π.D.Vf

Q = π.b.Vf

Q = π.D.bf.V

Q = D.b.Vf

^{1/2}

^{1/2}

^{3/2}

^{3/2}

(D/2d) + 5

(D/2d) + 10

(D/2d) + 15

(D/2d) + 20

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

6

8

12

(1 + cos φ)/2

(1 - cos φ)/2

(1 + sin φ)/2

(1 - sin φ)/2

Directly as fan speed

Square of fan speed

Cube of fan speed

Square root of fan speed

Increases

Decreases

Remain unaffected

First increases and then decreases

Centrifugal pump

Mixed flow pump

Axial flow pump

Any one of the above

waVr /g × (Vr + v)

waVr /g × (Vr - v)

waVr /g × (Vr + v)²

waVr /g × (Vr - v)²

24.8 r.p.m.

48.2 r.p.m

82.4 r.p.m.

248 r.p.m

Inlet of draft rube

Blade inlet

Guide blade

Penstock

Radially, axially

Axially, radially

Axially, axially

Radially, radially

_{m}) / (Q × η_{o})

_{m} Q) / η_{o}

_{m} × η_{o})

_{o}) / H_{m}

0 to 4.5

10 to 100

80 to 200

250 to 300

P/ √H

P/ H

^{3/2}

P/ H²

Proportional to diameter of impeller

Proportional to speed of impeller

Proportional to diameter and speed of impeller

None of the above

_{h} = η_{o} × η_{m}

_{m} = η_{m} × η_{h}

_{o} = η_{h} × η_{m}

None of these

_{r} - v) v]/ V_{r}²

_{r} + v) v]/ V_{r}²

_{r} - v) v]/ V_{r}

_{r} + v) v]/ V_{r}

One-fourth

One-half

Three-fourth

Double

Directly proportional

Inversely proportional

4th power

None of these

Greater than 15°

Greater than 8°

Greater than 5°

Less than 8°

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.

39.2 %

49.2 %

68.8 %

84.8 %