The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is _______ of the jet velocity,

A jet of water is striking at the centre of a curved vane moving with a uniform velocity in the direction of jet. For the maximum efficiency, the vane velocity is ________ of the jet velocity

A

One-half

B

One-third

C

Two-third

D

Three-fourth

The efficiency of a pressure-velocity compounded impulse turbine is __________ as compared to pressure compounded impulse turbine.

A

Same

B

Less

C

More

D

None of these

A circular wheel 28 inches in diameter rotates the same number of inches per second as a circular wheel 35 inches in diameter. If the smaller wheel makes x revolutions per second, how many revolutions per minutes does the larger wheel make in terms of x?

A

12x

B

24x

C

36x

D

48x

A wheel that has 6 cogs is meshed with a wheel of 14 cogs. When the smaller wheel has made 21 revolutions the number of revelution made by the larger wheel is --

A

4

B

9

C

12

D

49

A circular wheel 28 inches in diameter rotates (moves) the same number of inches per second as a circular wheel 35 inches in diameter. If the smaller wheel makes x revolutions per second, how many revolutions per minute does the larger wheel make in terms of x?

A

12x

B

48x

C

24x

D

36x

The hydraulic efficiency of an impulse turbine is the

A

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

B

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

C

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

D

None of the above

The force exerted by a jet of water impinging normally on a plate which due to the impact of jet, moves in the direction of jet with a velocity v is

A

$$\frac{{{\text{wa}}\left( {{\text{V}} - {\text{v}}} \right)}}{{2{\text{g}}}}$$

B

$$\frac{{{\text{wa}}\left( {{\text{V}} - {\text{v}}} \right)}}{{\text{g}}}$$

C

$$\frac{{{\text{wa}}{{\left( {{\text{V}} - {\text{v}}} \right)}^2}}}{{2{\text{g}}}}$$

D

$$\frac{{{\text{wa}}{{\left( {{\text{V}} - {\text{v}}} \right)}^2}}}{{\text{g}}}$$

The maximum number of jets, generally, employed in an impulse turbine without jet interference are

A

Two

B

Four

C

Six

D

Eight

The maximum number of jets generally employed in impulse turbine without jet interference is

A

4

B

6

C

8

D

12

There is a certain pressure ratio (optimum) for a gas turbine at which its thermal efficiency is maximum. With increase in turbine temperature, the value of pressure ratio for the peak efficiency would

A

Remain same

B

Decrease

C

Increase

D

None of the above

The hydraulic efficiency of an impulse turbine is maximum when velocity of wheel is _______ of the jet velocity,

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