Introduction: The design of a simple electric generator is performed to testify three important physical concepts using three hypotheses. Based on the transformation and conservation of energy, knowing that the total energy of an isolated system cannot change, but can transform from other forms. The first hypothesis is that turning the nail can lighten the light bulb, which can testify to the basic idea of ​​electromagnetic induction. The second hypothesis is that the number of coils wound on the device is the decisive factor in deciding whether the light bulb is lightened or not. This is the application of the solenoid whereby the strength of the magnetic field produced by a current is directly proportional to the number of turns in the solenoid. The third hypothesizes that the small light bulb will light up after rotating the magnet at a certain speed. This may reflect electromagnetic induction which explains the process of transformation of magnetic force into electromotive force through a conductor. Comparative experiments are needed to test the second and third hypotheses, while the first is not necessary. Materials: four ceramic magnets, 90m magnetic wire, a miniature lamp, a piece of cardboard strip and a large nail. Methods: First create the box cavity with ends. First fold it and then fix it firmly. Use the large nail to poke a hole in the center of the box, going through both sides of the box. Enlarge the hole slightly, it will increase the rotation speed. Lock the four magnets on both sides of the nail. Try spinning it and make sure the box is large enough for the magnets to spin freely. This will also make it easier to rotate and increase speed. Cut two small square pieces from cardboard, stick them and glue them between the magnet in the center of the paper......nt of the single conductors cutting the magnetic field, the amount of induced voltage produced will be the sum of all the individual circuits of the coil. Secondly, the difference in brightness of two operations using different speeds can demonstrate that if the same coil of wire passes through the same magnetic field but its speed is increased, the wire will cut the flux lines at a faster speed so as to produce more induced voltage. Quote: 1. Science Fair Project: Ultra-Simple Electrical Generator, Construction. (n.d.). Science Fair Project: Ultra-Simple Electric Generator, Construction. Retrieved May 1, 2014, from http://amasci.com/coilgen/generator_1.html2.Electromagnetic Induction and Faradays Law. (n.d.). Basic electronics tutorial. Retrieved May 1, 2014, from http://www.electronics-tutorials.ws/electromagnetism/electromagnetic-induction.html