1.
A optically active material
A
changes the direction of propagation of light
B
changes the direction of reflected light
C
changes the intensity of reflected light
D
changes the direction of the plane of polarization
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A optically active material
changes the direction of propagation of light
changes the direction of reflected light
changes the intensity of reflected light
changes the direction of the plane of polarization
Wind energy is harnessed as...............energy with the help of windmill or turbine
Mechanical
Solar
Electrical
Heat
Who invented the first electricity-generating wind turbine?
French engineer Georges J. M. Darrieus
Scottish engineer James Blyth
American inventor Benjamin Franklin
American inventor Charles F. Brush
Which U.S. state gets the highest percentage of its electricity from wind?
Kansas
Iowa
Texas
South Dakota
Which of these is NOT an example of distributed wind generation?
A 50-kilowatt turbine at an office building
A large, 100-megawatt wind farm
A 1.5-megawatt turbine at a university campus
A small, 5-kilowatt turbine at a home
Which of these is NOT a part of a modern wind turbine?
Compressor
Gearbox
Nacelle
Yaw drive
Which nation leads the world in installed wind energy capacity?
Netherlands
China
United States
Germany
What is the earliest recorded use for windmills?
Generating electricity
Pumping water
Jousting
Grinding grain
What causes wind?
Rotation of the Earth
The Sun heating the atmosphere
Variations in the Earths surface
All of the above
Uneven heating occurs on land surface and water bodies are due to
Air Currents
Solar radiation
Lunar eclipse
None of the above
Turbines blades have..............type cross section to extract energy from wind
Aerofoil
Elliptical
Rectangular
All of the above
The wind speed is measured using an instrument called
Pyranometer
Manometer
Anemometer
Wind vane
The wind intensity can be described by
Reynolds number
Mach number
Beaufort number
Froude number
The rate of change of wind speed with height is called
Wind shear
Wind rose
Wind solidity
None of the above
The following is the tangential velocity of the blade due to the rotation of blade
Wind velocity
Incident wind velocity
Blade linear velocity
Relative velocity
The atmosphere with uniform wind speed is called the..............atmosphere
Plain
Surface
Free
Shear
The amount of energy available in the wind at any instant is proportional to...............of the wind speed
Square root power of two
Square root power of three
Square power
Cube power
Roughly how tall are most utility-scale wind turbine towers in the U.S.?
65 meters (213 feet)
114 meters (374 feet)
88 meters (289 feet)
140 meters (460 feet)
Low solidity rotors use which of the following force for rotation
Drag
Lift
Centrifugal
Centripetal
How many offshore wind farms are there in the U.S.?
1
2
3
4