Renewable Energy Practice Test 6

1. Why is it necessary to have an optimal tip speed ratio (TSR)?

To ensure maximum efficiency

To ensure good aerodynamics

To ensure minimum efficiency but good aerodynamics

To increase drag

2. Which of following are considered during wind siting?

Safety impact, community impact, environmental impact

Radiation

Water

Sunlight

3. Which of the following is a mechanical application of wind energy?

Pumping water

Wind surfing

Lighting

Electricity

4. What is a vertical wind turbine?

Wind turbines are rotate about an axis perpendicular to the plane of wind streamlines

Wind turbines are rotate about an axis parallel to the plane of ground

Wind turbines are rotate about an axis diagonal to the plane of ground

Wind turbines are rotate about an axis 30 degrees to the plane of ground

5. What is wind speed?

Net molecular flux along the wind axis divided by the mean molecular number density

Net molecular flux along the wind axis divided by molecular number density

Molecular flux opposite the wind axis divided by the mean molecular number density

Molecular flux along the wind axis divided by the mean molecular number density

6. Why does wind speed increase with height above ground?

Gas molecules have less mass

More obstructions and slip boundary conditions

More slip boundary conditions

Less obstructions and no slip boundary conditions

7. How is drag force experienced by the blade reduced in various modern blade designs?

Using heavy metals

Bending and tapering the blade

Increasing the length of the blade

Twirling the blade

8. When plotting lift vs angle of attack, which of following best describes the shape of the curve?

Exponential

Cubic

Parabolic

Linear

9. What is sea breeze?

Winds from sea that flow during day towards the land and replace the lighter and rising hot air

Short gusts originating from sea

Winds that hit the land to generate extremely weak winds which spreads in all directions

Winds that don’t strike the ground level

10. Which of the following involves studying the physics of wind flow?

Microbial fuel cells

Polymer science

Combustion

Fluid dynamics