1.When the thicknesses of vanes are to be considered in the discharge of a turbine, what will be the area under consideration?
a) Pi*d – n*t
b) Pi*d – n*n*t
c) Pi*d – t*t
d) Pi*d *d– n*t
Explanation: When the thicknesses of vanes are to be considered in the discharge of a turbine, and n is the number of vanes, are is given by Pi*d – n*t.
2. The speed ratio is defined as u/(2gH)1/2
a) True
b) False
Explanation: The speed ratio is termed to be the ratio of tangential velocity at inlet to square root of 2gH.
3.Flow ratio is defined as Vf1/(2gH)1/2
a) False
b) True
Explanation: Flow ratio is the ratio between velocities of flow at inlet to square root of 2gH. Here, H is the head of the turbine.
4. _________ means the angle made by absolute velocity with the tangent on the wheel is 90 degrees and the component of whirl velocity is zero.
a) Axial discharge
b) Tangential discharge
c) Turbulent discharge
d) Radial discharge
Explanation: Radial discharge is the angle made by absolute velocity with the tangent on the wheel is 90 degrees and the component of whirl velocity is zero. Radial discharge at outlet means the angle beta is 90.
5. In a Francis turbine, degree of reaction lies between _____
a) 0 and 1
b) 1 and 2
c) 0 and 0.5
d) 0.5 and 0.1
Explanation: For a Francis turbine, theoretically and practically, 0< R< 1
6. In an outward flow reaction turbine, water from casing enters guiding wheel.
a) True
b) False
Explanation: Water enters the stationary guide wheel from the casing of the turbine in the outward radial flow reaction turbine
7. The water from penstocks enters the _____ which is spiral in shape which the area of cross section of casing goes on decreasing gradually
a) guide wheel
b) draft tube
c) casing
d) runner
Explanation: The water from penstocks enters the casing which is spiral in shape in which the area of cross section of casing decreases gradually.
8. If the water flows from inwards to outwards, the turbine is known as _____________
a) Tangential flow turbine
b) Turbulent low inward flow
c) Inward flow turbine
d) Outward flow turbine
Explanation: If the water in the runner flows from inwards to outwards, then such type of turbine is said to be outward radial flow turbine.
9.In general, reaction turbines consist of which types of energies?
a) kinetic energy and potential energy
b) potential energy and pressure energy
c) kinetic energy and pressure energy
d) gravitational energy and potential energy
Explanation: Reaction turbine is a kind of turbine in which the water at inlet of the turbine possesses both kinetic energy and pressure energy.
10. ___________ is a circular wheel on which a series of smooth, radial curved vanes are fixed.
a) Guide wheel
b) Runner
c) Casing
d) Draft tube
Explanation: The radial curved vanes are so shaped that water enters and leaves the runner without shock .It is a circular type wheel on which a series of smooth, radial curved vanes are fixed.