How pushing the pedals of a bicycle can make a bulb light up?

How pushing the pedals of a bicycle can make a bulb light up?
Using a magnetic Dynamo on a bicycle at the rear rim or the front rim. A magnetic Dynamo produces D.C (direct current) due to magnetic induction, this can be used to power a bulb on the bicycle. The two magnets do not come in contact as htey are separated by some distance and as the cycle gains speed the revolutions of the tyres become faster and the amount of current generated is directly propotional to the RPM( revolutions per minute).Therefore the intensity of the bulb is not consitent if the speed of the bicycle is not consistent.Magnetic Induction: When one magnet is moved to and fro with respect to another magnet with opposite facing it (the distance has to be short) with a good frequency, it produces current opposite to the direction of the moving magnet. This is because the magnet field strength (intensity) changes with respect to the distance between the two magnets. This changes in turn produces current.