Hydraulic Machines

41. Multistage centrifugal pumps are used to obtain

1. high discharge
2. high head
3. pumping of viscous fluids
4. high head and high discharge
5. high efficiency.

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42. One horsepower is equal to

1. 102 watts
2. 75 watts
3. 550 watts
4. 735 watts
5. 33000 watts.

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43. Pressure intensifier increases the pressure in proportion to

1. ratio of diameters
2. square of ratio of diameters
3. inverse ratio of diameters
4. square of inverse ratio of diameters
5. fourth power of ratio of diameters.

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44. Puck up the wrong statement about centrifugal pump

1. discharge a diameter
2. head a speed2
3. head a diameter
4. Power a speed3
5. none of the above is wrong.

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45. Reaction turbines are used for

1. low head
2. high head
3. high head and low discharge
4. high head and high discharge
5. low head and high discharge.

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46. Reciprocating pumps are no more to be seen in industrial applications (in comparison to centrifugal pumps) because of

1. high initial and maintenance cost
2. lower discharge
3. lower speed of operation
4. necessity of air vessel
5. all of the above.

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47. Runaway speed of a hydraulic turbine is

1. full load speed
2. the speed at which turbine runner will be damaged
3. the speed if the turbine runner is allowed to revolve freely without load and with the wicket gates wide open
4. the speed corresponding to maximum overload permissible
5. none of the above.

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48. Saving of work done and power by fitting an air vessel to double acting reciprocating pump is of the order of

1. 39.2%
2. 49.2%
3. 68.8%
4. 84.8%
5. 91.6%.

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49. Saving of work done and power by fitting an air vessel to single acting reciprocating pump is of the order of

1. 39.2%
2. 49.2%
3. 68.8%
4. 84.8%
5. 91.6%.

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50. Specific speed for reaction turbines ranges from

1. 0 to 4.5
2. 10 to 100
3. 80 to 200
4. 250 to 300
5. none of the above.

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