Question

write the principle of working of a wind mill

Answer 1

windmill converts wind energy into rotational energy by means of its blades. The basic principle of every windmill is to convert kinetic energy of wind into mechanical energy which is used to rotate the turbine of electrical generator to produce electricity. They are sometimes used to pump water or to extract groundwater. 
The most commonly seen windmills are Horizontal axis windmills which have their main rotor shaft and electrical generator at the top of a tower arranged in a row, horizontally

Answer 2

Hi mate!!!

Here is your answer

Wind turbines work on a simple principle: instead of using electricity to make wind—like a fan—wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.

Thanks for asking....