Introduction: The design of a simple electric generator is carried out to demonstrate three important physical concepts by three hypotheses. Based on the transformation and conservation of energy, knowing that the total energy of an isolated system cannot change, but can be transformed from other forms. The first hypothesis is that rotating the nail can illuminate the light bulb, which may attest to the basic idea of ​​electromagnetic induction. The second assumption is that the number of coils wound on the device is the deciding factor in whether the bulb is lit or not. This is the application of the solenoid where the strength of the magnetic field produced by a current is directly proportional to the number of turns in the solenoid. The third hypothesis assumes that the small bulb will light up after rotating the magnet at a certain speed. This can reflect electromagnetic induction which explains the process of transforming magnetic force into electromotive force through a conductor. Comparative experiments are necessary to testify to the second and third hypotheses while the first does not need them. Materials: Four ceramic magnets, 300 feet of magnetic wire, a miniature lamp, a piece of cardboard strip, and a large nail. Methods: First make the hollow-finished box. Fold it first, then glue it securely. Use the large nail to punch a hole in the center of the box, going through both sides of the box. Widen the hole slightly, this will increase the rotation speed. Attach the four magnets to both sides of the nail. Try spinning it and make sure the box is big enough for the magnets to spin freely. This will also make spinning easier and increase speed. Cut out two pieces of small square from cardboard, stuff them and stick them between the magnet to attach...... the middle of the paper ......nt of individual conductors crossing the magnetic field, the amount of induced voltage produced will be the sum of all the individual loops of the coil. Secondly, the difference in brightness of two operations using different speed can prove that if the same spool of wire passed through the magnetic field. same magnetic field but its speed or velocity is increased, the wire will cut the flux lines at a faster rate, which would produce more induced voltage. Citation: 1.Science fair project: ultra-simple electric generator, construction. (nd). Science fair project: Ultra-simple electric generator, construction. Retrieved May 1, 2014, from http://amasci.com/coilgen/generator_1.html2. Electromagnetic induction and Faraday's law. (nd). Basic electronics tutorials. Accessed May 1, 2014 from http://www.electronics-tutorials.ws/electromagnetisme/electromagnetisme-induction.html