MCQOPTIONS
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MCQOPTIONS
This section includes 2158 Mcqs, each offering curated multiple-choice questions to sharpen your GATE (Mechanical Engineering) knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
Due to which of the following phenomena water hammer is caused? |
| A. | Incompressibility of fluid |
| B. | Sudden opening of a valve in a pipeline |
| C. | The material of the pipe being elastic |
| D. | Sudden closure (partial or complete) of a valve in pipe flow. |
| Answer» E. | |
| 152. |
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» B. The pump will consume more power. | |
| 153. |
...... is a curve which gives an instantaneous picture of the location of the fluid particles which have passedthrough a given point. |
| A. | Path line |
| B. | Stream line |
| C. | Streak line |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 154. |
In case of turbulent flow of a fluid through a circular tube (as compared to the case of laminar flow at the same flow rate) the maximum velocity is ....., shear stress at the wall is ....., and the pressure drop across a given length is ....., the correct words for the blanks are, respectively |
| A. | lower, higher, lower |
| B. | lower, higher, higher |
| C. | higher, lower, lower |
| D. | higher, higher, higher |
| Answer» C. higher, lower, lower | |
| 155. |
The momentum correction factor β is used to account for: |
| A. | Change in direction of flow |
| B. | Change in total energy |
| C. | Non-uniform distribution of velocities at inlet and outlet sections |
| D. | Change in mass rate of flow. |
| Answer» D. Change in mass rate of flow. | |
| 156. |
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» E. | |
| 157. |
...... is important in compressible fluid flow problems at high velocities, such as high velocity flow in pipes or motion of high-speed projectiles and missiles. |
| A. | Euler’s number |
| B. | Mach’s number |
| C. | Reynolds number |
| D. | Froude’s number. |
| Answer» C. Reynolds number | |
| 158. |
......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» D. Volumetric efficiency. | |
| 159. |
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» B. Low head and small quantity of flow | |
| 160. |
A stream line is one |
| A. | In which stream function does not change |
| B. | In which the flow cannot cross the bounding surface |
| C. | Which has a constant area throughout its length so that the velocity remains constant. |
| D. | None of the above. |
| Answer» C. Which has a constant area throughout its length so that the velocity remains constant. | |
| 161. |
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» C. 0.35 to 0.5 | |
| 162. |
The path followed by fluid particle in motion is called a |
| A. | Streamline |
| B. | Path line |
| C. | Streak line |
| D. | None of the above. |
| Answer» C. Streak line | |
| 163. |
12. If the Reynolds number is less than 2000, the flow in a pipe is |
| A. | Laminar flow |
| B. | Turbulent flow |
| C. | Transition flow |
| D. | None of the above. |
| Answer» B. Turbulent flow | |
| 164. |
..... 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» E. | |
| 165. |
The point of application of the total pressure on the surface is |
| A. | Centroid of the surface |
| B. | Centre of pressure |
| C. | Either of the above |
| D. | None of the above. |
| Answer» C. Either of the above | |
| 166. |
The intensity of pressure in a liquid due to its depth will vary .... with depth. |
| A. | Directly |
| B. | Indirectly |
| C. | Either of the above |
| D. | None of the above. |
| Answer» B. Indirectly | |
| 167. |
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» B. Speed of the pump is low | |
| 168. |
The hydraulic gradient-line indicates the variation of which of the following: |
| A. | Velocity head in flow direction |
| B. | Piezometric head in the direction of flow |
| C. | Total energy of flow in the direction of flow |
| D. | None of the above. |
| Answer» C. Total energy of flow in the direction of flow | |
| 169. |
.......... possesses no definite volume and is compressible. |
| A. | Solid |
| B. | Liquid |
| C. | Gas |
| D. | Vapour. |
| Answer» D. Vapour. | |
| 170. |
Which of the following statements is correct in case of a Pelton wheel : |
| A. | It can operate at optimum efficiency at all high speeds |
| B. | It is kept entirely submerged in water below the tail race. |
| C. | It gives optimum efficiency at runaway speed |
| D. | It operates by converting the available energy fully into kinetic energy before entering the rotor. |
| Answer» E. | |
| 171. |
....... is defined mathematically as the line integral of the tangential velocity about a closed path (contour). |
| A. | Circulation |
| B. | Vorticity |
| C. | Either of the above |
| D. | None of the above. |
| Answer» B. Vorticity | |
| 172. |
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» B. 0.25 to 0.40 | |
| 173. |
Distorted models are required to be prepared for which of the following? |
| A. | Rivers |
| B. | Dams across very wide rivers |
| C. | Harbours |
| D. | All of the above. |
| Answer» E. | |
| 174. |
The momentum correction factor b for a circular pipe is to equal to |
| A. | 1/3 |
| B. | 2/3 |
| C. | 4/3 |
| D. | 5/3 |
| Answer» D. 5/3 | |
| 175. |
The pressure ....... as the depth of the liquid increases. |
| A. | Increases |
| B. | Decreases |
| C. | Remain unchanged |
| D. | None of the above. |
| Answer» B. Decreases | |
| 176. |
The pressure of a liquid on a surface will always act ...... to the surface. |
| A. | Parallel |
| B. | Normal |
| C. | 45° |
| D. | 60°. |
| Answer» C. 45° | |
| 177. |
The concept of stream function which is based on the principle of continuity is applicable to |
| A. | Irrotational flow only |
| B. | Two-dimensional flow only |
| C. | Three-dimensional flow |
| D. | Uniform flow only. |
| Answer» C. Three-dimensional flow | |
| 178. |
Surface tension is caused by the force of ..... at the free surface. |
| A. | Cohesion |
| B. | Adhesion |
| C. | Both (a) and (b) |
| D. | None of the above. |
| Answer» B. Adhesion | |
| 179. |
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» C. The draft tube allows setting of the turbine above the tail race with minimum reduction of available energy | |
| 180. |
The ratio of the specific weight of the liquid to the specific weight of a standard fluid is known as |
| A. | Specific volume |
| B. | Weight density |
| C. | Specific gravity |
| D. | Viscosity. |
| Answer» D. Viscosity. | |
| 181. |
In a turbulent flow, Reynold’s number is |
| A. | Less than 4000 |
| B. | More than 4000 |
| C. | Between 2000 and 4000 |
| D. | None of the above. |
| Answer» C. Between 2000 and 4000 | |
| 182. |
“The intensity of pressure at any point in a liquid at rest is the same in all directions.” The above statementis known as |
| A. | Kirchhoff’s law |
| B. | Pascal’s law |
| C. | Either of the above |
| D. | None of the above. |
| Answer» C. Either of the above | |
| 183. |
The side of the dam to which the water from the river or the stream approaches is known as |
| A. | Downstream |
| B. | Upstream |
| C. | Either of the above |
| D. | None of the above. |
| Answer» C. Either of the above | |
| 184. |
…... is the most commonly used equation for the velocity distribution for laminar flow through pipes. |
| A. | u = umax [1 – (r/R)] |
| B. | u = umax [1- (r/R)2] |
| C. | u = umax [1 – (r/R)3] |
| D. | u = u2max [1 – (r/R)2] |
| Answer» C. u = umax [1 – (r/R)3] | |
| 185. |
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» D. Increase the rate of flow | |
| 186. |
Fluids which do not follow the linear relationship between shear stress and rate of deformation are termedas.... fluids. |
| A. | Newtonian |
| B. | Non-Newtonian |
| C. | Dilatant |
| D. | ideal |
| Answer» C. Dilatant | |
| 187. |
Intensity of turbulence is |
| A. | The average K.E. of turbulence |
| B. | The violence of turbulent fluctuations and is measured by the root mean square value of velocity fluctuations |
| C. | The mean time interval between the reversals in the sign of velocity fluctuation |
| D. | None of the above. |
| Answer» C. The mean time interval between the reversals in the sign of velocity fluctuation | |
| 188. |
In turbulent flow the velocity distribution is a function of the distance y measured from the boundary surface and shear friction velocity uf, and follows a |
| A. | Linear law |
| B. | Hyperbolic law |
| C. | Parabolic law |
| D. | Logarithmic law. |
| Answer» E. | |
| 189. |
For achieving continuous flow through a system, no position of the pipe should be higher than |
| A. | 20 m |
| B. | 6 m |
| C. | 7·6 m |
| D. | 10 m. |
| Answer» D. 10 m. | |
| 190. |
Flow between parallel plates of infinite extent is an example of |
| A. | One-dimensional flow |
| B. | Two-dimensional flow |
| C. | Three-dimensional flow |
| D. | Compressible flow. |
| Answer» C. Three-dimensional flow | |
| 191. |
The most essential feature of a turbulent flow is |
| A. | High velocity |
| B. | Velocity at a point remains constant with time |
| C. | Large discharge |
| D. | Velocity and pressure at a point exhibit irregular fluctuations of high frequency. |
| Answer» E. | |
| 192. |
The value of bulk modulus of elasticity .......... with increase of pressure. |
| A. | Increases |
| B. | Decreases |
| C. | Either of the above |
| D. | None of the above. |
| Answer» B. Decreases | |
| 193. |
The laminar/viscous flow is characterized by Reynolds number which is |
| A. | less than the critical value |
| B. | Equal to critical value |
| C. | More than critical value |
| D. | None of the above. |
| Answer» B. Equal to critical value | |
| 194. |
dimensionally homogeneous equation is applicable to |
| A. | C.G.S. system only |
| B. | F.P.S. system only |
| C. | M.K.S. and SI systems |
| D. | All systems of units. |
| Answer» E. | |
| 195. |
An irrational flow is one in which |
| A. | The stream lines of flow are curved and closely spaced |
| B. | The fluid does not rotate as it moves along |
| C. | The net rotation of fluid particles about their mass centres remains zero |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 196. |
If the flow is irrational as well as steady it is known as |
| A. | Non-uniform flow |
| B. | One-dimensional flow |
| C. | Potential flow |
| D. | None of the above. |
| Answer» D. None of the above. | |
| 197. |
For a centrifugal pump impeller, the maximum value of the vane exit angle is |
| A. | 10o to 15o |
| B. | 15o to 20o |
| C. | 20o to 25o |
| D. | 25o to 30o |
| Answer» D. 25o to 30o | |
| 198. |
Discharge of a centrifugal pump is (where N= speed of the pump impeller) |
| A. | directly proportional to n |
| B. | inversely proportional to n |
| C. | directly proportional to n2 |
| D. | inversely proportional to n2 |
| Answer» B. inversely proportional to n | |
| 199. |
The specific speed from a centrifugal pump indicates that the pump is |
| A. | slow speed at radial flow at outlet |
| B. | medium speed with radial flow at outlet |
| C. | high speed with radial flow at outlet |
| D. | high speed with axial flow at outlet |
| Answer» E. | |
| 200. |
The specific speed of a centrifugal pump, delivering 750 liters of water per second against a head of15 meters at 725r.p.m., is |
| A. | 24.8r.p.m. |
| B. | 48.2r.p.m. |
| C. | 82.4r.p.m. |
| D. | 248r.p.m. |
| Answer» D. 248r.p.m. | |