Question

The power generated in a windmill depends on the ___ of wind

Answer 1

The wind makes the rotor spin; as the rotor spins, the movement of the blades spinning gives power to a generator which produces electricity. So the more the velocity of the wind is, the more will the blades spin and the more will be power generated.
The motion of the wind turbine turning is called kinetic energy, this power is converted into electricity.