McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Civil Engineering , Mechanical Engineering .
Chapters
| 101. |
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» A. less than the critical value | |
| 102. |
The laminar flow is characterized by |
| A. | Existence of eddies |
| B. | Irregular motion of fluid particles |
| C. | Fluid particles moving in layers parallel to the boundary surface |
| D. | None of the above. |
| Answer» C. Fluid particles moving in layers parallel to the boundary surface | |
| 103. |
In case of laminar flow, the loss of pressure head is proportional to |
| A. | Velocity |
| B. | Velocity2 |
| C. | Velocity3 |
| D. | None of the above. |
| Answer» A. Velocity | |
| 104. |
The pressure gradient in the direction of flow is equal to the shear gradient in the direction |
| A. | Parallel to the direction of flow |
| B. | Normal to the direction of flow |
| C. | Either of the above |
| D. | None of the above. |
| Answer» B. Normal to the direction of flow | |
| 105. |
…... studied the laminar flow through a circular tube experimentally |
| A. | Prandtl |
| B. | Pascal |
| C. | Hagen and Poiseuille |
| D. | None of the above. |
| Answer» C. Hagen and Poiseuille | |
| 106. |
…... 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» B. u = umax [1- (r/R)2] | |
| 107. |
In laminar flow the pressure drop per unit length of pipe (∆p/L) is given as |
| A. | 32𝜇͞u/D2 |
| B. | 2𝜇͞u/D2 |
| C. | 32𝜇͞u/D3 |
| D. | None of above. |
| Answer» A. 32𝜇͞u/D2 | |
| 108. |
The K.E. correction factor a for a circular pipe is equal to |
| A. | 2 |
| B. | 3 |
| C. | 4 |
| D. | 6. |
| Answer» A. 2 | |
| 109. |
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» C. 4/3 | |
| 110. |
For viscous flow the co-efficient of friction is given by |
| A. | f = 8/Re |
| B. | f = 16/Re |
| C. | f = 32/Re |
| D. | f = 60/Re. |
| Answer» B. f = 16/Re | |
| 111. |
In case of viscous flow through circular pipes |
| A. | ͞u = 2 umax |
| B. | u = (3/2) umax |
| C. | u = umax/2 |
| D. | none of the above. |
| Answer» B. u = (3/2) umax | |
| 112. |
The maximum velocity in a circular pipe when flow is laminar occurs at |
| A. | The top of the pipe |
| B. | The bottom of the pipe |
| C. | The centre of the pipe |
| D. | Not necessarily at the centre. |
| Answer» C. The centre of the pipe | |
| 113. |
The flow is said to be turbulent when Reynolds number is |
| A. | Less than 1000 |
| B. | Equal to 2000 |
| C. | Greater than 4000 |
| D. | Between 1000 to 4000. |
| Answer» C. Greater than 4000 | |
| 114. |
The shear in turbulent flow is mainly due to |
| A. | Heat transfer |
| B. | Mass transfer |
| C. | Momentum transfer |
| D. | All of the above. |
| Answer» C. Momentum transfer | |
| 115. |
Which of the following statements is correct? Wall turbulence occurs |
| A. | In immediate vicinity of solid surfaces and in the boundary layer flows where the fluid has a negligible mean acceleration |
| B. | In jets, wakes, mixing layer etc. |
| C. | Where there is conversion of potential energy into kinetic energy by the process of mixing |
| D. | None of the above. |
| Answer» A. In immediate vicinity of solid surfaces and in the boundary layer flows where the fluid has a negligible mean acceleration | |
| 116. |
The flow in town water supply pipes is generally |
| A. | Laminar |
| B. | Turbulent |
| C. | Transition |
| D. | Any of the above. |
| Answer» B. Turbulent | |
| 117. |
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» D. Velocity and pressure at a point exhibit irregular fluctuations of high frequency. | |
| 118. |
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» D. Logarithmic law. | |
| 119. |
A turbulent flow is considered steady when |
| A. | The algebraic sum of velocity fluctuations is zero |
| B. | The velocity at a point does not change with Time |
| C. | Temporal mean velocity at a point remains constant with time |
| D. | The discharge remains constant. |
| Answer» C. Temporal mean velocity at a point remains constant with time | |
| 120. |
The Darcy-Weisbach friction factor f which is a direct measure of resistance to flow in pipes depends on which of the following? |
| A. | Relative roughness, velocity and viscosity |
| B. | Relative roughness, diameter and viscosity |
| C. | Roughness height, diameter and velocity |
| D. | Roughness height, diameter, velocity and kinematic viscosity. |
| Answer» D. Roughness height, diameter, velocity and kinematic viscosity. | |
| 121. |
Commercial cast-iron and steel pipes carrying fluids under pressure are regarded as hydraulically smooth when |
| A. | The laminar layer is thin as compared to the average height of roughness elements |
| B. | The height of the roughness projections is low |
| C. | The roughness elements are all completely covered by the laminar sublayer |
| D. | None of the above. |
| Answer» C. The roughness elements are all completely covered by the laminar sublayer | |
| 122. |
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» B. The violence of turbulent fluctuations and is measured by the root mean square value of velocity fluctuations | |
| 123. |
Which of the following factors determine the friction factor for turbulent flow in a rough pipe? |
| A. | Mach number and relative roughness |
| B. | Froude’s number and Mach’s number |
| C. | Reynolds number and relative roughness |
| D. | Froude’s number and relative roughness. |
| Answer» C. Reynolds number and relative roughness | |
| 124. |
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» B. lower, higher, higher | |
| 125. |
In a laminar flow, Reynold’s number is |
| A. | Less than 2000 |
| B. | More than 2000 |
| C. | More than 2000 but less than 4000 |
| D. | None of the above. |
| Answer» A. Less than 2000 | |
| 126. |
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» B. More than 4000 | |
| 127. |
In case of a laminar flow, the loss of pressure head is |
| A. | Proportional to (velocity)2 |
| B. | Proportional to velocity |
| C. | Proportional to (velocity)1/2 |
| D. | None of the above. |
| Answer» B. Proportional to velocity | |
| 128. |
In case of a turbulent flow, the loss of head is approximately proportional to |
| A. | Velocity |
| B. | (Velocity) ^1/2 |
| C. | (Velocity) ^3/4 |
| D. | (Velocity) ^2 |
| Answer» D. (Velocity) ^2 | |
| 129. |
Darcy-Weisbach equation is used to find loss of head due to : |
| A. | Sudden enlargement |
| B. | Sudden contraction |
| C. | Friction |
| D. | None of the above. |
| Answer» C. Friction | |
| 130. |
Chezy’s formula is given as |
| A. | V = C √𝑚2 i |
| B. | V = C2 √𝑚𝑖2 |
| C. | V = C√𝑚𝑖 |
| D. | V = C √𝑚2𝑖3 |
| Answer» C. V = C√𝑚𝑖 | |
| 131. |
Loss of head due to sudden enlargement is given as |
| A. | (𝑉1−𝑉2)32𝑔 |
| B. | (𝑉1−𝑉2)22𝑔 |
| C. | (𝑉12−𝑉22)2𝑔 |
| D. | √(𝑉1−𝑉2)2𝑔 |
| Answer» B. (𝑉1−𝑉2)22𝑔 | |
| 132. |
2𝑔 148. The power transmitted through the pipe is maximum when head lost due to friction in the pipe is equal to |
| A. | (1/3) rd of the total supply head |
| B. | (1/4) th of the total supply head |
| C. | (1/5) th of the total supply head |
| D. | (1/8) th of the total supply head |
| Answer» C. (1/5) th of the total supply head | |
| 133. |
The energy loss in a pipeline is due to |
| A. | Surface roughness only |
| B. | Viscous action only |
| C. | Friction offered by pipe wall as well as by viscous function |
| D. | None of the above. |
| Answer» C. Friction offered by pipe wall as well as by viscous function | |
| 134. |
In a pipe flow the minor losses are those |
| A. | Which depend on the length of the pipeline |
| B. | Caused by friction and are thus also called friction losses. |
| C. | Which have a small magnitude |
| D. | Which are caused on account of total disturbance produced by such fittings as valves, bends, etc. |
| Answer» D. Which are caused on account of total disturbance produced by such fittings as valves, bends, etc. | |
| 135. |
In flow through pipe bends the pressures on inner and out radii |
| A. | Stand at the same level increasing gradually towards the pipe center. |
| B. | Vary, it being more on the inner core. |
| C. | Are different, pressure increases with increase in radius and is, therefore, more at the outer radius. |
| D. | Do not vary and are the same as at the center of the pipe. |
| Answer» D. Do not vary and are the same as at the center of the pipe. | |
| 136. |
The condition for maximum transmission of power through a pipeline is that one-third of the available head must be consumed in friction. The corresponding efficiency of the pipeline is |
| A. | 33·3% |
| B. | 66·67% |
| C. | 90% |
| D. | 100%. |
| Answer» B. 66·67% | |
| 137. |
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» C. 7·6 m | |
| 138. |
For turbulent flow in smooth pipes, the entrance length is taken as |
| A. | 20 |
| B. | 50 |
| C. | 80 |
| D. | 115. |
| Answer» B. 50 | |
| 139. |
The entrance length or length of establishment of flow is |
| A. | The length in which the boundary layer remains uniform |
| B. | The pipe length inside the reservoir |
| C. | The length of pipe from its entrance in which the flow may be assumed irrotational |
| D. | The initial length in which the flow develops fully such that the velocity profile does not change downstream. |
| Answer» D. The initial length in which the flow develops fully such that the velocity profile does not change downstream. | |
| 140. |
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» D. Sudden closure (partial or complete) of a valve in pipe flow. | |
| 141. |
Under which of the following conditions the closure of valve is considered rapid? (where L = length of pipe, C = velocity of pressure wave produced due to water hammer.) |
| A. | The duration of valve closure is greater than 2L/C |
| B. | The duration of valve closure is less than L/C |
| C. | The duration of valve closure is less than 2L/C |
| D. | None of the above. |
| Answer» C. The duration of valve closure is less than 2L/C | |
| 142. |
The force exerted by a jet of water on a moving vertical plate, in the direction of motion of plate is given by |
| A. | ρaV2 |
| B. | ρaV3 |
| C. | ρa (V – u)2 |
| D. | ρa (V – u)3 |
| Answer» C. ρa (V – u)2 | |
| 143. |
When a steady jet impinges on a fixed inclined surface |
| A. | The flow is divided into parts proportional to the angle of inclination of the surface |
| B. | No force is exerted by the jet on the vane |
| C. | The momentum component is unchanged parallel to the surface |
| D. | None of the above. |
| Answer» A. The flow is divided into parts proportional to the angle of inclination of the surface | |
| 144. |
For maximum efficiency of a series of curved vanes, the speed is |
| A. | Equal to the jet speed |
| B. | 3/4 of the jet speed |
| C. | 1/2 of the jet speed |
| D. | 1/3 of the jet speed. |
| Answer» C. 1/2 of the jet speed | |
| 145. |
The efficiency of jet propulsion with inlet orifices at right angles to the direction of motion of ship is given by |
| A. | 2u/ (V + u) |
| B. | 2V/ (V + u) 2 |
| C. | 2Vu/ (V + u) 2 |
| D. | 2u (V-u)/V3 |
| Answer» B. 2V/ (V + u) 2 | |
| 146. |
For an impulse turbine which of the following statements is correct : |
| A. | It makes use of a draft tube |
| B. | It is not exposed to atmosphere |
| C. | It is most suited for low head installations |
| D. | It operates with initial complete conversion of pressure head to velocity head. |
| Answer» D. It operates with initial complete conversion of pressure head to velocity head. | |
| 147. |
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» D. It operates by converting the available energy fully into kinetic energy before entering the rotor. | |
| 148. |
The effective (or net) head at the turbine is |
| A. | The sum of gross head plus head loss in penstock and the velocity head at the turbine exit. |
| B. | The difference between gross head minus the head loss in penstock |
| C. | The difference between the gross head minus head loss in penstock and the velocity head at the turbine exit |
| D. | The sum of gross head plus the head loss in the penstock. |
| Answer» C. The difference between the gross head minus head loss in penstock and the velocity head at the turbine exit | |
| 149. |
The difference between the power obtained from the turbine shaft and power supplied by water at its entry to the turbine is equal to |
| A. | Sum of hydraulic and mechanical losses |
| B. | Sum of mechanical and volumetric losses |
| C. | Mechanical losses |
| D. | Hydraulic losses. |
| Answer» A. Sum of hydraulic and mechanical losses | |
| 150. |
Which of the following statements is a definition of the hydraulic efficiency of a turbine? |
| A. | The ratio of power available at the turbine shaft to that supplied to it by runner. |
| B. | The ratio of the power supplied by the runner to the power available at the shaft. |
| C. | The ratio of power utilized by runner to that supplied by the water at entry to the turbine. |
| D. | The ratio of power supplied by water at entry to the power utilized by runner. |
| Answer» C. The ratio of power utilized by runner to that supplied by the water at entry to the turbine. | |
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.