1. Kaplan turbine is needed to improve ________
a) Increase Pressure
b) Decrease temperature
c) Change volume
d) Increase efficiency
Explanation: Kaplan turbine is needed to improve efficiencies at low speeds. When we arrange turbine blades in multiple stages. It plays an essential role in turbines.
2. Kaplan turbine is an ________ type turbine
a) Pressure
b) Inward flow
c) Outward flow
d) Velocity
Explanation: Kaplan turbine is an inward flow reaction turbine. It means that the working fluid changes its pressure as it moves through the turbine and gives up its energy.
3. The turbine does not have to be at the lowest point of water flow as long as the water in the draft tube is full.
a) True
b) False
Explanation: The turbine does not have to be at the lowest point of water flow as long as the water in the draft tube is full. A higher turbine located increases the suction and is imparted on the turbine blades by the draft tube.
4.The outlet of the Kaplan turbine is through _______
a) Vane Blades
b) Moving pipeline
c) Draft tube
d) Pump
Explanation: The outlet of the Kaplan turbine is through draft tube. It is a specially shaped tube that helps to decelerate the water and recover its kinetic energy. It happens at a faster rate.
5. Kaplan turbine is most commonly used in propeller turbines.
a) True
b) False
Explanation: Kaplan turbine is most commonly used in propeller turbines. Since, the Kaplan turbines have non-adjustable propeller vanes it is most commonly used. They are used in a wide rage if flow and for other commercial products.
6. For a Kaplan turbine, the whirl velocity at inlet of the turbine is given to be 18 m/s. The blade velocity is given as 25 m/s. What is the hydraulic efficiency for a head of 50 m. Take g = 10 m/s2?
a) 80%
b) 90%
c) 70%
d) 98%
Explanation: The hydraulic efficiency of a Kaplan turbine is given by ηh = Vw1.u1/ gH. Substituting the values of the given parameters in the equation, we get hydraulic efficiency = 90%.
7. Which of the following efficiencies for Kaplan Turbine is described as the ratio between the power produced by runner to the power supplied by water at the inlet?
a) Hydraulic efficiency
b) Volumetric efficiency
c) Mechanical efficiency
d) Overall efficiency
Explanation: The definition of Hydraulic efficiency in a Kaplan turbine states that it is the ratio between the Runner power to the shaft power. Hence, the correct option is Hydraulic efficiency.
8.The desired hydraulic efficiency of a Kaplan turbine is 98% at a whirl velocity of 20 m/s and a head of 60 m. What should be the blade velocity of the turbine at inlet in m/s? Take g = 10 m/s2.
a) 40
b) 60
c) 80
d) 30
Explanation: The hydraulic efficiency of a Kaplan turbine is given by ηh = Vw1.u1/ gH. Substituting the values of the given parameters in the equation, we get blade velocity at the inlet as 29.4 m/s which can be roughly approximated to 30 m/s.
9. It is given that the input water power of the Kaplan turbine is 1.10 times the runner power. What would be the hydraulic efficiency of the turbine (in %)?
a) 60.61
b) 70.71
c) 80.81
d) 90.91
Explanation: The definition of Hydraulic efficiency in a Kaplan turbine states that it is the ratio between the Runner power to the shaft power. If input water power is 1.10 times the runner power, the runner power is 1/1.10 = 0.90909 Times the water power. Hence, hydraulic efficiency = 90.91%.
10. Which of the following efficiencies for Kaplan Turbine is described as the ratio between total quantity of water over runner blades to total quantity of water supplied to turbine?
a) Hydraulic efficiency
b) Volumetric efficiency
c) Mechanical efficiency
d) Overall efficiency
Explanation: The definition of volumetric efficiency in a Kaplan turbine states that it is the ratio between the total volume of water flowing over the runner blades to the volume of water entering the turbine. Hence, the correct option is volumetric efficiency.