MCQOPTIONS
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MCQOPTIONS
This section includes 42 Mcqs, each offering curated multiple-choice questions to sharpen your Fluid Mechanics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Consider the following statements:1. Surge tanks are not substitute for forebays.2. Pumped storage power plants are a boon to power generation.3. Water hammer in penstocks is not dangerous.4. Kaplan turbines are used in low head power plants.Which of the above statements are correct? |
| A. | 2 and 4 only |
| B. | 1 and 4 only |
| C. | 2 and 3 only |
| D. | 1 and 3 only |
| Answer» B. 1 and 4 only | |
| 2. |
A hydraulic turbine develops 8000 kW when running at 300 rpm under a head of 45 m. the speed of the same turbine under a head of 60 m is |
| A. | 224.4 rpm |
| B. | 346.4 rpm |
| C. | 424.8 rpm |
| D. | 485.8 rpm |
| Answer» B. 346.4 rpm | |
| 3. |
Pick the correct order of various turbines with respect to specific speed. |
| A. | Pelton > Kaplan > Francis |
| B. | Francis > Pelton > Kaplan |
| C. | Kaplan > Francis > Pelton |
| D. | Kaplan > Pelton > Francis |
| Answer» D. Kaplan > Pelton > Francis | |
| 4. |
A water turbine delivering 10 MW power is to be tested with the help of a geometrically similar 1 : 10 model which runs at the same speed and efficiency. The power developed by the model will be: |
| A. | 10 W |
| B. | 100 W |
| C. | 1000 W |
| D. | 10000 W |
| Answer» C. 1000 W | |
| 5. |
In general sense, water turbines may be put in the following decreasing order of specific speeds as |
| A. | Kaplan turbine, Francis turbine and Pelton wheel |
| B. | Pelton wheel, Francis turbine and Kaplan turbine |
| C. | Francis turbine, Pelton wheel and Kaplan turbine |
| D. | Francis turbine, Kaplan turbine and Pelton wheel |
| Answer» B. Pelton wheel, Francis turbine and Kaplan turbine | |
| 6. |
Consider the following statements in connection with hydraulic turbines:1. The Kaplan turbine is a radial flow turbine in which the guide vane angles as well as the runner vane angles are adjustable.2. Francis and Kaplan turbines are provided with draft tubes which carry water from exit of runner to tail water to increase the gross head across the turbine.3. The parts of turbines susceptible to cavitation are the guide vanes and runner vanes – drastically reducing the turbine efficiency.4. The specific speed of a 4-jet Pelton turbine will be 28 if the specific speed of a single-jet Pelton turbine is 14.Which of the above statements are correct? |
| A. | 2 and 3 only |
| B. | 1 and 3 only |
| C. | 1 and 4 only |
| D. | 2 and 4 only |
| Answer» E. | |
| 7. |
Manometric head developed hm in m, and discharge Q in lps n respect of two pumps, 1 and 2, are tabulated. The pumps are connected in series against a static head of 100 m. Total head losses for a discharge of Q are as \(\frac{{{Q^2}}}{{100}}\left( m \right).\) What is the delivered discharge?Q in lps1518202225Hm1 in m60.661.262.055.048.0Hm2 in m50.851.048.845.840.0 |
| A. | 20.15 lps |
| B. | 21.25 lps |
| C. | 21.95 lps |
| D. | 22.20 lps |
| Answer» C. 21.95 lps | |
| 8. |
In water wheel, when water enters the bucket mounted on the periphery of a wheel at its top, it will be known as: |
| A. | Breast water wheel |
| B. | Under shot wheel |
| C. | Over shot wheel |
| D. | Pelton wheel |
| Answer» D. Pelton wheel | |
| 9. |
Hydroelectric power plant is |
| A. | non-renewable source of energy |
| B. | conventional source of energy |
| C. | non-conventional source of energy |
| D. | continuous source of energy |
| Answer» D. continuous source of energy | |
| 10. |
Consider the following statements regarding a turbine:1. Specific speed plays an important role in the selection of the type of turbine.2. An increase in specific speed of the turbine is accompanied by higher maximum efficiency.3. The runner of too high specific speed with high available head increases the cost of the turbine on account of the high mechanical strength required.Which of the above statements are correct? |
| A. | 1, 2 and 3 |
| B. | 1 and 2 only |
| C. | 1 and 3 only |
| D. | 2 and 3 only |
| Answer» D. 2 and 3 only | |
| 11. |
Fans and blowers of turbo machines: |
| A. | a higher static pressure will prevail |
| B. | spiral casing decreases the static pressure |
| C. | deliver air at a higher desired velocity |
| D. | deliver air at a lower mass flow rate |
| Answer» D. deliver air at a lower mass flow rate | |
| 12. |
_____ is closely related to working of hydraulic turbines. |
| A. | Bragg’s law |
| B. | Newton’s second law |
| C. | Faraday’s law |
| D. | Charles’ law |
| Answer» C. Faraday’s law | |
| 13. |
In the context of roto-dynamic machines, which of the following statements is correct? |
| A. | There will be a relative motion between the rotor vanes and the fluid. |
| B. | While flowing through the stator, linear momentum changes. |
| C. | Linear momentum is the direction normal to the rotor. |
| D. | Linear momentum is normal to the stator. |
| Answer» B. While flowing through the stator, linear momentum changes. | |
| 14. |
Match the pair:(a) Run of river planti. Large storage(b) Reservoir plantii. Water pumped back to the head water tank(c) Pumped storage plantiii. Sea water(d) Tidal plantiv. No storage |
| A. | (a) – iii, (b) – i, (c) – iv, (d) – ii |
| B. | (a) – iv, (b) – ii, (c) – iii, (d) – i |
| C. | (a) – iv, (b) – i, (c) – ii, (d) – iii |
| D. | (a) – iv, (b) – iii, (c) – i, (d) – ii |
| Answer» D. (a) – iv, (b) – iii, (c) – i, (d) – ii | |
| 15. |
If the speed of a pump is doubled then the head developed by it will be |
| A. | Double |
| B. | Three times |
| C. | Four times |
| D. | Half |
| Answer» D. Half | |
| 16. |
A rough estimate of the total installed capacity of hydropower stations in Karnataka is |
| A. | 5000 kW |
| B. | 3000 MW |
| C. | 8000 MW |
| D. | 10000 kW |
| Answer» C. 8000 MW | |
| 17. |
If the peak load on a power plant having a capacity of 100 MW is 70 MW during a given week (7-days), and the energy produced is 5880000 kWh, the capacity factor (in %) for the plant for the said week is |
| A. | 35 |
| B. | 50 |
| C. | 65 |
| D. | 30 |
| E. | 70 |
| Answer» B. 50 | |
| 18. |
In the turbine flow meter, the rotor movement is sensed by a |
| A. | Optical pick-up |
| B. | Photovoltaic pick |
| C. | Reluctance pick-up |
| D. | Piezoelectric pick-up |
| Answer» E. | |
| 19. |
Consider the following statements regarding turbines:I. the main function of a governor is to maintain a constant speed even as the load on the turbine fluctuates2. In the cast of Pelton turbines, the governor closes or opens the wicket gates3. In the case of Francis turbines, the governor opens or closes the needle valve4. In the case of a Kaplan turbine, the governor swings the runner blades appropriately in addition to further Closing or further opening of wicket gatesWhich of the above statements are correct? |
| A. | 1 and 3 only |
| B. | 2 and 4 only |
| C. | 2 and 3 only |
| D. | 1 and 4 only |
| Answer» E. | |
| 20. |
In the hydel system, a forebay is used at the junction of _________. |
| A. | penstock and turbine |
| B. | power channel and penstock |
| C. | power channel and tailrace channel |
| D. | headrace channel and penstock |
| Answer» E. | |
| 21. |
Gross head is the difference between- |
| A. | Head race and net head |
| B. | Head race and tail race |
| C. | Net head and friction losses |
| D. | Head race and friction losses |
| Answer» C. Net head and friction losses | |
| 22. |
Consider the following statements:1. In an Impulse turbine, the pressure of the flowing water remains un- changed and is equal to atmospheric Pressure.2. In Impulse turbines, the water impinges on the buckets with ‘Pressure energy’.3. In a Reaction turbine, the pressure of the flowing water remains un- changed and is equal to atmospheric pressure.Which of the above statements is/are correct? |
| A. | 1 only |
| B. | 2 only |
| C. | 3 only |
| D. | 1, 2 and 3 |
| Answer» B. 2 only | |
| 23. |
Hydraulic intensifier is a device used for |
| A. | storing energy of fluid in the form of pressure energy |
| B. | increasing pressure intensity of fluid |
| C. | transmitting power from one shaft to other |
| D. | none of the above |
| Answer» C. transmitting power from one shaft to other | |
| 24. |
How many impellers are required for a multi-stage pump to lift 4000 lpm against a total head of 80 m at a speed of 750 rpm; given that Ns for each impeller should be between 720 to 780 units? |
| A. | 6 |
| B. | 5 |
| C. | 4 |
| D. | 3 |
| Answer» C. 4 | |
| 25. |
A specific speed varying from 8.5 to 30 in turbine is classified as _________. |
| A. | Reaction turbine |
| B. | Pelton wheel |
| C. | Kaplan turbine |
| D. | Francis turbine |
| Answer» C. Kaplan turbine | |
| 26. |
If the power factor of an AC electrical power system is 0.7 and the real power given is 1 kW, Calculate the apparent power. |
| A. | 1.7 kVA |
| B. | 1.43 kVA |
| C. | 0.7 kVA |
| D. | 0.3 kVA |
| Answer» C. 0.7 kVA | |
| 27. |
A fan running at 720 rpm develops static pressure of 12 mm. If the speed of the fan is doubled the static pressure developed will be |
| A. | 24 mm |
| B. | 12 mm |
| C. | 48 mm |
| D. | 96 mm |
| Answer» D. 96 mm | |
| 28. |
In a hydraulic machine, the moment of momentum of water is reduced by 15915 N.m, when the machine is rotating at 600 rpm. The power developed is |
| A. | 1000 kW |
| B. | 1500 kW |
| C. | 2000 kW |
| D. | 2500 kW |
| Answer» B. 1500 kW | |
| 29. |
A centrifugal pump lifts 100 l / s of a liquid against a net head of 150 kPa. The brake power required is 18.0 kW when the liquid is water with a specific weight of 9.8 kN / m3. What would be the brake power if the liquid is a solvent having a relative density of 0.8 instead of water, with all other factors remaining the same as before? |
| A. | 14.4 kW |
| B. | 18.0 kW |
| C. | 22.5 kW |
| D. | 17.2 kW |
| Answer» B. 18.0 kW | |
| 30. |
A certain hydropower plant utilizes the flow as it occurs, without any provision for storage.It is premised that a defined minimum dry-weather flow is available. Such a plant is classified as |
| A. | Diverted-flow plant |
| B. | Pooled storage plant |
| C. | Base-load plant |
| D. | Run-of-river plant |
| Answer» E. | |
| 31. |
If the energy present in a jet of water of 20 cm diameter and having a velocity of 25 m/s could be extracted by a device with 90% efficiency, the power extracted would be nearly \(\left( {taking\frac{1}{{2g}} = 0.051\frac{{\sec 2}}{m}} \right)\) |
| A. | 180 kW |
| B. | 255 kW |
| C. | 260 kW |
| D. | 300 kW |
| Answer» C. 260 kW | |
| 32. |
______ are those which are capable of working under heads less than 30 m. |
| A. | Low head turbine |
| B. | Medium head turbine |
| C. | High head turbine |
| D. | None of above |
| Answer» B. Medium head turbine | |
| 33. |
A large hydraulic turbine is to generate 300 kW at 1000 rpm under a head of 40 m for initial testing, a 1:4 scale model of the turbine operates under a head of 10 m. The power generated by the model (in kW) will be |
| A. | 2.34 |
| B. | 4.68 |
| C. | 9.38 |
| D. | 18.75 |
| Answer» B. 4.68 | |
| 34. |
At the point of operation with maximum efficiency, a turbine indicated unit power of 12 units and unit speed of 98 units and operates with 3300 kgf/s of flow, what are the speed in rpm and the specific speed of the machine respectively when its design head is 8.5 m? |
| A. | 285 rpm and 339 |
| B. | 270 rpm and 360 |
| C. | 285 rpm and 360 |
| D. | 270 rpm and 339 |
| Answer» B. 270 rpm and 360 | |
| 35. |
__________ engines can work in vacuum. |
| A. | Turbojet |
| B. | Rocket |
| C. | Turboprop |
| D. | Ramjet |
| Answer» C. Turboprop | |
| 36. |
Hydraulic coupling belongs to the category of: |
| A. | Power developing machine |
| B. | Energy transfer machine |
| C. | Power absorbing machine |
| D. | Energy generating machine |
| Answer» C. Power absorbing machine | |
| 37. |
Identify the false statement from the following:The specific speed of the turbine increases with _______ |
| A. | increase in shaft speed |
| B. | increase in discharge |
| C. | decrease in gravitational acceleration |
| D. | increase in head |
| Answer» E. | |
| 38. |
A dynamic car converts chemical energy into |
| A. | Electrical energy |
| B. | Mechanical energy |
| C. | Chemical energy |
| D. | Nuclear energy |
| Answer» C. Chemical energy | |
| 39. |
Cavitation is likely to occur if1. Pressure becomes very high.2. Temperature becomes low.3. Pressure at the specific point falls below vapour pressure.4. Energy is released with the onset of a high intensity wave due to noise and vibration of the machine.Which of the above statements are correct? |
| A. | 1 and 3 |
| B. | 2 and 3 |
| C. | 3 and 4 |
| D. | 2 and 4 |
| Answer» D. 2 and 4 | |
| 40. |
In a centrifugal pump, a wheel which is provided with a series of backward curved blades or vanes is classified as: |
| A. | Impeller |
| B. | Suction pipe |
| C. | Delivery pipe |
| D. | Casing |
| Answer» B. Suction pipe | |
| 41. |
A nozzle has a velocity head at an outlet of 10 m. If the jet is vertical, the height reached by the stream is |
| A. | 100 m |
| B. | \(\sqrt{10} ~m\) |
| C. | 10 m |
| D. | \({1 \over \sqrt{10}} ~m\) |
| Answer» D. \({1 \over \sqrt{10}} ~m\) | |
| 42. |
In case of semi-circular vanes, what can be the theoretical maximum efficiency of the wheel? |
| A. | 75% |
| B. | 100% |
| C. | 67% |
| D. | 50% |
| Answer» C. 67% | |