which device is designed to change electrical energy into mechanical energy?\na fan\nb lamp\nc windmill\nd…

Brief Explanations:

A fan uses an electric - motor. When electricity is supplied to the fan's motor, the motor rotates the fan blades, converting electrical energy into mechanical energy. A lamp converts electrical energy into light (and some heat). A windmill converts wind (mechanical) energy into electrical energy. A stove converts electrical energy into heat energy.

Answer:

A. Fan