Wind Turbine Test

What is the mass per unit volume of Earth's atmosphere and is a useful value in aeronautics and other sciences?

• Air density
• Cut-out speed
• Generator
• Rotor
• Tip speed ratio

What is the area in the square feet of the rotor? It is also called the capture area.

• Swept area
• Air density
• Cut-out speed
• Generator
• Rotor

What converts the turning motion of a wind turbine's blades into electricity?

• Generator
• Air density
• Cut-out speed
• Rotor
• Tip speed ratio

At very high wind speeds, typically between 45 and 80mph, most wind turbines cease power generation and shut down. This wind speed is known as what?

• Cut-out speed
• Air density
• Generator
• Rotor
• Tip speed ratio

What part of a wind turbine raise the wind turbine so that its blades safely clear the ground and all it to reach stronger winds at higher elevations?

• Tower
• Air density
• Cut-out speed
• Generator
• Rotor

What is the part of the wind turbine that collects energy from the wind? It usually consists of two or more wooden, fiberglass, or metal blades that rotate about an axis.

• Rotor
• Air density
• Cut-out speed
• Generator
• Tip speed ratio

What is the ratio of the rotational speed of the blade to the wind speed? The larger this ratio, the faster the rotation of the wind turbine rotor and a given speed.

• Tip speed ratio
• Air density
• Cut-out speed
• Generator
• Rotor

The swept area of a wind turbine is:

• the circle formed by the rotating blades of the rotor.
• the minimum distance required when spacing turbines in a line.
• the minimum height from the base of the tower to the bottom of the nacelle.
• the length of one rotor multiplied by the tower height.

The wind possesses energy by virtue of its mass and speed. For example, a cubic meter of air moving at 10m/s has about 60 J of kinetic energy. Which of the following energy values might one expect for this same air after flowing through a mechanical device, such as a wind turbine?

• 0 J
• 30 J
• 60 J
• 120 J

Albert Betz determine the maximum efficiency for wind turbine blades in 1919. What is this value?

• 39.3%
• 49.3%
• 59.3%
• 69.3%