MCQOPTIONS
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MCQOPTIONS
This section includes 657 Mcqs, each offering curated multiple-choice questions to sharpen your Testing Subject knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Which of the following statement is correct as regard to water wheels? |
| A. | They have slow speeds. |
| B. | They are suitable even for low water heads. |
| C. | They give constant efficiency, even if the discharge is not constant |
| D. | all of the above |
| Answer» E. | |
| 2. |
The centrifugal pump preferred for a specific speed between 80 to 160 r.p.m. is |
| A. | slow speed with radial flow at outlet |
| B. | medium speed with radial flow at outlet |
| C. | high speed with radial flow at outlet |
| D. | high speed with mixed flow at outlet |
| Answer» E. | |
| 3. |
The efficiency of a reaction turbine for a given head __________ with the increase in speed. |
| A. | decreases |
| B. | increases |
| Answer» B. increases | |
| 4. |
The speed ratio in case of Francis turbine varies from |
| A. | 0.15 to 0.3 |
| B. | 0.4 to 0.5 |
| C. | 0.6 to 0.9 |
| D. | 1 to 1.5 |
| Answer» D. 1 to 1.5 | |
| 5. |
A Kaplan turbine is preferred for a specific speed of 300 to 1000 r.p.m. |
| A. | Yes |
| B. | No |
| Answer» B. No | |
| 6. |
The width of the bucket for a Pelton wheel is generally __________ the diameter of jet. |
| A. | double |
| B. | three times |
| C. | four times |
| D. | five times |
| Answer» E. | |
| 7. |
The action of a centrifugal pump is that of a reversed reaction turbine. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 8. |
Which of the following is not a reaction turbine? |
| A. | Furneyron turbine |
| B. | Jonval turbine |
| C. | Thomson's turbine |
| D. | Pelton wheel |
| Answer» E. | |
| 9. |
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 |
| Answer» C. two-third | |
| 10. |
Which of the following pump is successfully used for lifting water to the turbines? |
| A. | Centrifugal pump |
| B. | Reciprocating pump |
| C. | Jet pump |
| D. | Air lift pump |
| Answer» D. Air lift pump | |
| 11. |
The efficiency of jet propulsion for a ship with inlet orifices at right angles to the direction of motion of ship is given by |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-11-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-11-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-11-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-11-4.png"> |
| Answer» B. <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-11-2.png"> | |
| 12. |
Which of the following statement is correct ? |
| A. | The centrifugal pump is suitable for large discharge and smaller heads. |
| B. | The centrifugal pump requires less floor area and simple foundation as compared to reciprocating pump. |
| C. | The efficiency of centrifugal pump is less as compared to reciprocating pump. |
| D. | all of the above |
| Answer» E. | |
| 13. |
For 450 m head of water, __________ shallbeused. |
| A. | Pelton wheel |
| B. | Kaplan turbine |
| C. | Francis turbine |
| D. | none of these |
| Answer» B. Kaplan turbine | |
| 14. |
A turbine develops 10000 kW under a head of 25 metres at 135 r.p.m. Its specific speed is |
| A. | 175.4 r.p.m. |
| B. | 215.5 r.p.m. |
| C. | 241.5 r.p.m. |
| D. | 275.4 r.p.m |
| Answer» D. 275.4 r.p.m | |
| 15. |
In an impulse turbine, the pressure of water both at entering and leaving the vanes, is atmospheric. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 16. |
Which of the following pump is successfully used for lifting water from deep wells? |
| A. | Centrifugal pump |
| B. | Reciprocating pump |
| C. | Jet pump |
| D. | Air lift pump |
| Answer» E. | |
| 17. |
The Thomson's turbine is __________ reaction turbine. |
| A. | an axial flow |
| B. | an inward flow |
| C. | an outward flow |
| D. | a mixed flow |
| Answer» C. an outward flow | |
| 18. |
The water in a jet propelled boat is drawn through the openings facing the direction of motion of the boat. The efficiency of propulsion is given by |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-14-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-14-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-14-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-14-4.png"> |
| Answer» C. <img src="/_files/images/mechanical-engineering/hydraulic-machines/192-14-3.png"> | |
| 19. |
The ratio of the normal force of jet of water on a plate inclined at an angle of 30 as compared to that when the plate is normal to jet, is |
| A. | 1/ |
| B. | <span class="root">2</span> |
| C. | 1/2 |
| D. | 1 |
| E. | <span class="root">2</span> |
| Answer» C. 1/2 | |
| 20. |
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 |
| Answer» D. none of the above | |
| 21. |
The overall efficiency for a Pelton wheel lies between |
| A. | 0.50 to 0.65 |
| B. | 0.65 to 0.75 |
| C. | 0.75 to 0.85 |
| D. | 0.85 to 0.90 |
| Answer» E. | |
| 22. |
Head developed by a centrifugal pump is |
| A. | proportional to diameter of impeller |
| B. | proportional to speed of impeller |
| C. | proportional to diameter and speed of impeller |
| D. | none of the above |
| Answer» D. none of the above | |
| 23. |
If the ratio of all the corresponding linear dimensions are equal, then the model and the prototype are said to have |
| A. | geometric similarity |
| B. | kinematic similarity |
| C. | dynamic similarity |
| D. | none of these |
| Answer» B. kinematic similarity | |
| 24. |
The efficiency of a hydraulic press is given by (where W = Weight lifted by ram, P = Force applied on plunger, A = Area of ram, and a = Area of plunger) |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/205-164-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/205-164-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/205-164-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/205-164-4.png"> |
| Answer» D. <img src="/_files/images/mechanical-engineering/hydraulic-machines/205-164-4.png"> | |
| 25. |
Braking jet in an impulse turbine is used |
| A. | to break the jet of water |
| B. | to bring the runner to rest in a short time |
| C. | to change the direction of runner |
| D. | none of these |
| Answer» C. to change the direction of runner | |
| 26. |
If the net positive suction head (NPSH) requirement for the pump is not satisfied, then |
| A. | no flow will take place |
| B. | cavitation will be formed |
| C. | efficiency will be low |
| D. | excessive power will be consumed |
| Answer» C. efficiency will be low | |
| 27. |
Slip of a reciprocating pump is negative, when |
| A. | suction pipe is short and pump is running at low speeds |
| B. | delivery pipe is long and pump is running at high speeds |
| C. | suction pipe is short and delivery pipe is long and the pump is running at low speeds |
| D. | suction pipe is long and delivery pipe is short and the pump is running at high speeds |
| Answer» E. | |
| 28. |
Which of the following is not an impulse turbine? |
| A. | Girad turbine |
| B. | Turgo turbine |
| C. | Pelton wheel |
| D. | Kaplan turbine |
| Answer» E. | |
| 29. |
A hydraulic accumulator is a device used to store __________ energy which may be supplied to a machine later on. |
| A. | strain |
| B. | pressure |
| C. | kinetic |
| Answer» C. kinetic | |
| 30. |
The Furneyron turbine is __________ reaction turbine. |
| A. | an axial flow |
| B. | an inward flow |
| C. | an outward flow |
| D. | a mixed flow |
| Answer» D. a mixed flow | |
| 31. |
The expansion of steam in a nozzle follows |
| A. | Carnot cycle |
| B. | Rankine cycle |
| C. | Joule cycle |
| D. | Stirling cycle |
| Answer» C. Joule cycle | |
| 32. |
The velocity of whirl at outlet for an axial discharge turbine is |
| A. | minimum |
| B. | maximum |
| C. | zero |
| Answer» D. | |
| 33. |
In impulse turbines, when friction is neglected, the relative velocity of steam at outlet tip of the blade is __________ the relative velocity of steam at inlet tip of the blade. |
| A. | equal to |
| B. | less than |
| C. | greater than |
| Answer» B. less than | |
| 34. |
A reciprocating pump is also called a __________ displacement pump. |
| A. | positive |
| B. | negative |
| Answer» B. negative | |
| 35. |
The head available at the inlet of the turbine is known as net or effective head. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 36. |
Power required to drive a centrifugal pump is __________ proportional to N3. |
| A. | directly |
| B. | inversely |
| Answer» B. inversely | |
| 37. |
The force exerted (in newton) by a jetof water impinging normally on a fixed plate is (where w = Specific weight of water in N/m3, a = Cross-sectional area of jet in m2, and V = Velocity of jet in m/s) |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/190-1-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/190-1-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/190-1-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/190-1-4.png"> |
| Answer» E. | |
| 38. |
The unit power developed by a turbine is (where P = Power developed by the turbine under a head of water (H)) |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-71-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-71-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-71-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-71-4.png"> |
| Answer» D. <img src="/_files/images/mechanical-engineering/hydraulic-machines/197-71-4.png"> | |
| 39. |
By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power. This saving in case of a single acting reciprocating pump is |
| A. | 39.2% |
| B. | 48, 8% |
| C. | 84.8% |
| D. | 88.4% |
| Answer» D. 88.4% | |
| 40. |
If the Francis turbine is run below 50 percent head for a long period, it will not only lose its efficiency but also the cavitation danger will become more serious. |
| A. | Agree |
| B. | Disagree |
| Answer» B. Disagree | |
| 41. |
The maximum hydraulic efficiency of an impulse turbine is (where = Angle of blade tip at outlet) |
| A. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/193-32-1.png"> |
| B. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/193-32-2.png"> |
| C. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/193-32-3.png"> |
| D. | <img src="/_files/images/mechanical-engineering/hydraulic-machines/193-32-4.png"> |
| Answer» B. <img src="/_files/images/mechanical-engineering/hydraulic-machines/193-32-2.png"> | |
| 42. |
In a Francis turbine runner, the number of blades are generally between |
| A. | 2 to 4 |
| B. | 4 to 8 |
| C. | 8 to l6 |
| D. | 16 to 24 |
| Answer» E. | |
| 43. |
By fitting an air vessel to the reciprocating pump, there is always a saving of work done and subsequently saving of power.The saving in case of a double acting reciprocating pump is |
| A. | 39.2% |
| B. | 48.8% |
| C. | 84.8% |
| D. | 88.4% |
| Answer» B. 48.8% | |
| 44. |
In a reciprocating pump, air vessels are used to |
| A. | smoothen the flow |
| B. | reduce suction head |
| C. | increase delivery head |
| D. | reduce acceleration head |
| Answer» E. | |
| 45. |
In a Francis turbine, the pressure at inlet is __________ that at outlet. |
| A. | less than |
| B. | more than |
| Answer» C. | |
| 46. |
If the ratio's of the corresponding forces acting at corresponding points are equal, then the model and the prototype are said to have. |
| A. | geometric similarity |
| B. | kinematic similarity |
| C. | dynamic similarity |
| D. | none of these |
| Answer» D. none of these | |
| 47. |
A Pelton wheel working under a constant head and discharge, has maximum efficiency when the speed ratio is |
| A. | 0.26 |
| B. | 0.36 |
| C. | 0, 46 |
| D. | 0.56 |
| Answer» D. 0.56 | |
| 48. |
In a mixed flow reaction turbine, the flow of water is partly radial and partly axial. |
| A. | Correct |
| B. | Incorrect |
| Answer» B. Incorrect | |
| 49. |
A Pelton wheel with one nozzle is preferred for a specific speed between 35 to 60 r.p.m. |
| A. | True |
| B. | False |
| Answer» C. | |
| 50. |
Which of the following pump is generally used to pump highly viscous fluid? |
| A. | Centrifugal pump |
| B. | Reciprocating pump |
| C. | Air lift pump |
| D. | Screw pump |
| Answer» E. | |