Awind powered generator converts wind energy into electrical energy. assume that the generator converts a fixed fraction of wind energy intercepted by its blades into electrical energy. for wind speed v electric power will be proportional to
a) v⁴
b) v²
c) v
d) v³

I'd go for b) v squared.
Wind is air in motion. So, it has kinetic energy. For a given mass of air at a certain speed, the kinetic energy would be (1/2)mv^2.
Since everything else in the chain seems to be proportional, then it's the v^2 bit that seems to be important. Hence the answer I post here.

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