A wind turbine is used to extract power from the wind.If the diameter of the turbine is doubled,the maximum power extracted from the wind will increase by a factor of
A)2
B)4
C)6
D)8
E)16

Question

Quizplus · Accepted Answer

The power extracted from the wind is proportional to the area covered by the turbine blades, which is proportional to the square of the diameter. Therefore, if the diameter is doubled, the area (and thus the maximum power extracted) will increase by a factor of 2^2 = 4. So, the correct answer is (B) 4.

A Wind Turbine Is Used to Extract Power from the Wind.If