Top 550+ Solved Fluid Mechanics and Hydraulic Machines MCQ Questions Answer
Q. 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.
Q. 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.
Q. 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.
Q. 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.
Q. 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.
Q. 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.
Q. 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.
Q. 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 spee
Q. The efficiency of jet propulsion with inlet orifices at right angles to the direction of motion of ship isgiven by
a. 2u/ (V + u)
b. 2V/ (V + u) 2
c. 2Vu/ (V + u) 2
d. 2u (V-u)/V3
Q. 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 hea
Q. 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.
Q. 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.
Q. 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.