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Potential energy to electrical energy
How it works
When the handgrip is rotated, the rubberband within the handgrip begins to wind. After some time, when it is released, the rubberband begins to unwind and in turn rotates the propeller and the motor. Usually when we supply power to a motor, it begins to spin. But here the motor spins and power is being generated at the other end of the motor. since that end is attached to a bulb, the bulb lights up.