Top 50+ Solved Impact of Jet and Hydraulic Turbines MCQ Questions Answer
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.
Q. 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.
Q. 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.
Q. 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 loa
Q. 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.
Q. 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
Q. 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.
Q. 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.
Q. 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.