McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Civil Engineering , Mechanical Engineering .
Chapters
| 151. |
The power which appears in the expression for the specific speed is the: |
| A. | Shaft power |
| B. | Water power |
| C. | Power into the turbine |
| D. | None of the above. |
| Answer» A. Shaft power | |
| 152. |
Which of the following statements is correct: Runaway speed of a hydraulic turbine is the speed |
| A. | At which there would be no damage to the turbine runner |
| B. | At which the turbine runner can be allowed to run freely without load and with wicket gates wide open |
| C. | Corresponding to maximum overload permissible |
| D. | At full load. |
| Answer» B. At which the turbine runner can be allowed to run freely without load and with wicket gates wide open | |
| 153. |
Which of the following statements is correct for a reaction turbine? |
| A. | The outlet must be above the tail race. |
| B. | Water may be allowed to enter a part or whole of wheel circumference. |
| C. | Flow can be regulated without loss. |
| D. | There is only partial conversion of available head to velocity head before entry to rotor. |
| Answer» D. There is only partial conversion of available head to velocity head before entry to rotor. | |
| 154. |
In a reaction turbine the function of a draft tube is to |
| A. | Provide safety to turbine |
| B. | Prevent air from entering |
| C. | Reconvert the kinetic energy to flow energy |
| D. | Increase the rate of flow |
| Answer» C. Reconvert the kinetic energy to flow energy | |
| 155. |
Which of the following statements with respect to a reaction water turbine is incorrect: |
| A. | The spiral casing serves to uniformly distribute water into guide blades |
| B. | The water leaves the turbine at atmospheric pressure |
| C. | The draft tube allows setting of the turbine above the tail race with minimum reduction of available energy |
| D. | The guide vanes direct the flow at proper angle. |
| Answer» B. The water leaves the turbine at atmospheric pressure | |
| 156. |
Which of the following turbines is suitable for specific speed ranging from 300 to 1000 and heads below 30 m: |
| A. | Francis |
| B. | Kaplan |
| C. | Propeller |
| D. | Pelton. |
| Answer» B. Kaplan | |
| 157. |
Specific speed of a turbo-machine |
| A. | Relates the shape rather than the size of the machine |
| B. | Remains unchanged under different condi tions of operation |
| C. | Has the dimensions of rotational speed |
| D. | Is the speed of a machine having unit dimensions. |
| Answer» A. Relates the shape rather than the size of the machine | |
| 158. |
In an outward radial flow turbine energy conversion process is |
| A. | Purely by reaction only |
| B. | Purely by impulse only |
| C. | Partly by impulse and partly by reaction |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 159. |
Which of the following turbines is least efficient under part load conditions: |
| A. | Propeller |
| B. | Kaplan |
| C. | Francis |
| D. | Pelton. |
| Answer» A. Propeller | |
| 160. |
A surge tank is used to |
| A. | Prevent occurrence of hydraulic jump |
| B. | Smoothen the flow |
| C. | Relieve the pipeline of excessive pressure transients |
| D. | Avoid reversal of flow. |
| Answer» C. Relieve the pipeline of excessive pressure transients | |
| 161. |
Which of the following turbines is most efficient at partload operation? |
| A. | Kaplan |
| B. | Propeller |
| C. | Francis |
| D. | Pelton wheel. |
| Answer» A. Kaplan | |
| 162. |
With respect to a Kaplan turbine which of the following statements is incorrect? |
| A. | It employs large guide vane angles than is the case for a Francis turbine. |
| B. | It is designed for flow velocity of mixed flow type. |
| C. | It has blades of small camber to prevent separation. |
| D. | It can adjust both guide vane and blade angles according to rate of discharge. |
| Answer» B. It is designed for flow velocity of mixed flow type. | |
| 163. |
Specific speed of an impulse turbine (Pelton wheel) ranges from |
| A. | 12 to 70 |
| B. | 80 to 400 |
| C. | 300 to 1000 |
| D. | 1000 to 1200. |
| Answer» A. 12 to 70 | |
| 164. |
Cavitation damage in turbine runner occurs near the |
| A. | Inlet on the convex side of blades |
| B. | Outlet on the convex side of blades |
| C. | Inlet on the concave side of blades |
| D. | Outlet on the concave side of blades. |
| Answer» B. Outlet on the convex side of blades | |
| 165. |
Which of the following serious problems arise from cavitation? |
| A. | Noise and vibration. |
| B. | Damage to blade surface. |
| C. | Fall in efficiency. |
| D. | All of the above. |
| Answer» D. All of the above. | |
| 166. |
A Kaplan turbine is |
| A. | An inward flow impulse turbine |
| B. | Low head axial flow turbine |
| C. | High head axial flow turbine |
| D. | High head mixed flow turbine. |
| Answer» B. Low head axial flow turbine | |
| 167. |
An impulse turbine requires |
| A. | High head and small quantity of flow |
| B. | Low head and small quantity of flow |
| C. | Low head and high rate of flow |
| D. | None of the above |
| Answer» A. High head and small quantity of flow | |
| 168. |
......of a turbine is defined as the ratio of power available at the turbine shaft to the power supplied by the water jet. |
| A. | Mechanical efficiency |
| B. | Hydraulic efficiency |
| C. | Overall efficiency |
| D. | Volumetric efficiency. |
| Answer» C. Overall efficiency | |
| 169. |
The ratio of power developed by the runner to the power supplied by the jet at entrance to the turbine is known as |
| A. | Hydraulic efficiency |
| B. | Mechanical efficiency |
| C. | Volumetric efficiency |
| D. | Overall efficiency. |
| Answer» A. Hydraulic efficiency | |
| 170. |
The water which acts on the runner blades of a reaction turbine is under a pressure |
| A. | Equal to atmospheric |
| B. | Below atmospheric |
| C. | Above atmospheric |
| D. | None of the above. |
| Answer» C. Above atmospheric | |
| 171. |
The runner passages of a reaction turbine are |
| A. | Partially filled with water |
| B. | Always completely filled with water |
| C. | Never filled with water |
| D. | None of the above. |
| Answer» B. Always completely filled with water | |
| 172. |
The value of speed ratio (Ku) in case of a Francis turbine ranges from |
| A. | 0.2 to 0.3 |
| B. | 0.4 to 0.5 |
| C. | 0.6 to 0.9 |
| D. | None of the above. |
| Answer» C. 0.6 to 0.9 | |
| 173. |
The value of flow ratio (Kf) in case of a Francis turbine varies from: |
| A. | 0.1 to 0.14 |
| B. | 0.15 to 0.30 |
| C. | 0.35 to 0.5 |
| D. | 0.6 to 0.9. |
| Answer» B. 0.15 to 0.30 | |
| 174. |
A Kaplan turbine claims which of the following advantages over a Francis turbine? |
| A. | More compact in construction and smaller in size. |
| B. | Partload efficiency is considerably high. |
| C. | Low frictional losses. |
| D. | All of the above. |
| Answer» D. All of the above. | |
| 175. |
Which of the following draft tubes is suited particularly for helical flow? |
| A. | Conical type draft tube. |
| B. | Elbow type draft tube. |
| C. | Moody’s spreading draft tube. |
| D. | None of the above. |
| Answer» C. Moody’s spreading draft tube. | |
| 176. |
Which of the following surge tank is also called a throttled surge tank? |
| A. | Inclined surge tank. |
| B. | Expansion chamber surge tank. |
| C. | Restricted orifice surge tank. |
| D. | None of the above |
| Answer» C. Restricted orifice surge tank. | |
| 177. |
Which of the following types of impeller is used for centrifugal pumps dealing with muds? |
| A. | One-side shrouded |
| B. | Two -sides shrouded |
| C. | Double section |
| D. | Open. |
| Answer» D. Open. | |
| 178. |
Which of the following statements is correct with reference to an impeller with backward curved vanes? |
| A. | It has a falling head - discharge characteristic. |
| B. | It has rising head - discharge characteristic |
| C. | It is easier to fabricate. |
| D. | It cannot run at speeds other than the design speed. |
| Answer» A. It has a falling head - discharge characteristic. | |
| 179. |
The head developed by a centrifugal pump may be expressed as |
| A. | H = (Vw2 u2 + Vw1 u2)/g |
| B. | H = Vw2 u2 /g |
| C. | H = Vw1 u1 /g |
| D. | None of the above. |
| Answer» B. H = Vw2 u2 /g | |
| 180. |
With reference to a centrifugal pump which of the following statements is incorrect? |
| A. | The discharge control valve is fitted in the delivery pipe. |
| B. | The suction pipe is provided with a foot valve and a strainer. |
| C. | The suction pipe has larger diameter as compared to the discharge pipe. |
| D. | The discharge control valve is fitted in the suction pipe. |
| Answer» D. The discharge control valve is fitted in the suction pipe. | |
| 181. |
A centrifugal pump should be so installed above the water level in the sump such that |
| A. | The negative pressures are not allowed to develop in the impeller |
| B. | The negative pressures do not reach as low a value as the vapour pressure |
| C. | Its height is more than 10·28 m at ordinary temperature of liquid |
| D. | None of the above. |
| Answer» B. The negative pressures do not reach as low a value as the vapour pressure | |
| 182. |
The specific speed of a pump is defined as the speed of unit of such a size that it |
| A. | Produces unit power with unit head available |
| B. | Delivers unit discharge at unit head |
| C. | Requires unit power to develop unit head |
| D. | Delivers unit discharge at unit power. |
| Answer» B. Delivers unit discharge at unit head | |
| 183. |
Which of the following statements pertaining to a given centrifugal pump is correct? |
| A. | Discharge varies as the square of speed |
| B. | Power varies as the square of speed |
| C. | Discharge varies directly as speed |
| D. | Head varies inversely as speed. |
| Answer» C. Discharge varies directly as speed | |
| 184. |
The delivery valve, while starting centrifugal pump, is kept |
| A. | Fully closed |
| B. | Fully open |
| C. | Half open |
| D. | In any position. |
| Answer» A. Fully closed | |
| 185. |
Which of the following is not a dimensionless parameter? |
| A. | Friction factor |
| B. | Specific speed |
| C. | Thoma’s cavitation parameter |
| D. | Pressure co-efficient. |
| Answer» B. Specific speed | |
| 186. |
With reference to manometric head which of the following statements is correct? |
| A. | It is the head developed by the pump. |
| B. | It is the height to which water is lifted by the pump measured above the pump centreline. |
| C. | it is the difference in elevation between the water surface in the high level reservoir and the water level in the sump. |
| D. | It is the difference in the piezometric heads between the points on the delivery and suction pipes as close to the pump as possible. |
| Answer» D. It is the difference in the piezometric heads between the points on the delivery and suction pipes as close to the pump as possible. | |
| 187. |
Higher specific speeds (160 to 500) of centrifugal pump indicate that the pump is of |
| A. | Radial flow type |
| B. | Axial flow type |
| C. | Mixed flow type |
| D. | Any of these types. |
| Answer» B. Axial flow type | |
| 188. |
What will happen if requirements of net positive suction head (NPSH) for a given pump are not satisfied? |
| A. | The pump will get cavitated. |
| B. | The pump will consume more power. |
| C. | The pump will not develop he |
| Answer» A. The pump will get cavitated. | |
| 189. |
In centrifugal pumps, cavitation is reduced by |
| A. | Increasing the flow velocity |
| B. | Reducing the discharge |
| C. | Throttling the discharge |
| D. | Reducing the suction head. |
| Answer» D. Reducing the suction head. | |
| 190. |
Which of the following statements pertaining to a centrifugal pump is incorrect? |
| A. | The suction lift of a pump can be upto 10·3 m or even more. |
| B. | The impellers of a multi-stage pump are arranged in parallel to discharge a large quantity of liquid. |
| C. | The volute casing of the pump maintains the velocity of flow constant, prevents eddies and converts velocity head to pressure he |
| Answer» A. The suction lift of a pump can be upto 10·3 m or even more. | |
| 191. |
Regarding cavitation which of the following statements in incorrect? |
| A. | Cavitation affects the performance of a turbine to a lesser degree than that of a pump. |
| B. | Thoma’s cavitation parameter has different expressions for turbines and pumps. |
| C. | With the increase in pump speed, there is increase in its minimum net positive suction head requirement. |
| D. | The leading edge of blades in pumps and the trailing edge of blades in water turbines are more susceptible to cavitation damage |
| Answer» B. Thoma’s cavitation parameter has different expressions for turbines and pumps. | |
| 192. |
A centrifugal pump is taking much of power, the probable reason may be |
| A. | Liquid being pumped is heavy |
| B. | Speed of the pump is low |
| C. | There is leakage of air |
| D. | Ineffective strainer and foot valve arrangement. |
| Answer» A. Liquid being pumped is heavy | |
| 193. |
In rotodynamic pumps, the increase in energy level is due to |
| A. | Centrifugal energy only |
| B. | Pressure energy only |
| C. | Kinetic energy only |
| D. | Combination of a, b and c. |
| Answer» D. Combination of a, b and c. | |
| 194. |
In a pump there is |
| A. | Accelerating flow |
| B. | Decelerated flow |
| C. | Either of the above |
| D. | None of the above. |
| Answer» A. Accelerating flow | |
| 195. |
In a centrifugal pump the regulating valve is provided on |
| A. | The suction pipe |
| B. | Delivery pipe |
| C. | The casing |
| D. | None of the above. |
| Answer» B. Delivery pipe | |
| 196. |
In a centrifugal pump the sum of suction head and delivery head is known as |
| A. | Monomeric head |
| B. | Total head |
| C. | Static head |
| D. | None of the above. |
| Answer» C. Static head | |
| 197. |
Regarding manometric head (Hmano) which of the following relations is correct? |
| A. | Hmano= head imparted by the impeller to the liquid – loss of head in the pump |
| B. | Hmano= static head + losses in pipes + Vd2/2g |
| C. | Hmano= total head at outlet of the pump - total head at inlet of pump |
| D. | All of the above. |
| Answer» D. All of the above. | |
| 198. |
The ratio of power outlet of the pump to the power input to the pump is known as |
| A. | Mechanical efficiency |
| B. | Overall efficiency |
| C. | Monomeric efficiency |
| D. | None of the above. |
| Answer» B. Overall efficiency | |
| 199. |
The flow ratio in case of a centrifugal pump varies from |
| A. | 0.1 to 0.25 |
| B. | 0.25 to 0.40 |
| C. | 0.40 to 0.50 |
| D. | 0.50 to 0.65 |
| Answer» A. 0.1 to 0.25 | |
| 200. |
..... is a device which increases the intensity of pressure of a given liquid with the help of low pressure liquid of large quantity. |
| A. | Hydraulic press |
| B. | Hydraulic crane |
| C. | Hydraulic accumulator |
| D. | Hydraulic intensifier. |
| Answer» D. Hydraulic intensifier. | |
Done Studing? Take A Test.
Great job completing your study session! Now it's time to put your knowledge to the test. Challenge yourself, see how much you've learned, and identify areas for improvement. Don’t worry, this is all part of the journey to mastery. Ready for the next step? Take a quiz to solidify what you've just studied.