In this experiment we are able to study the relationship between the induced current in a coil and the frequency of oscillation of a magnetic bar inside the coil . In 1820, Hans Christian Oersted, a Danish physicist, discovered the magnetic effect of a current-carrying conductor (wire) when it passes through a current, and this will affect the magnetic field around the wire. [search in the reference book]. His discovery led to the inventions of the dynamo, the motor and the telephone thanks to electromagnetism. As a bar magnet, it is surrounded by its own magnetic field and magnetic field lines. The properties of magnetic field lines are that they always flow from the North Pole to the South Pole. The North Pole always goes out and the South Pole always goes in. Additionally, magnetic field lines cannot cross each other. Likewise, the more concentrated the magnetic field lines, the greater the strength of magnetism. The study of magnetic fields began in 1269 when French scholar Petrus Peregrinus de Maricourt mapped the magnetic field on the surface of a spherical magnet using iron needles [search Wikipedia]. The magnetic field is a region in which a magnetic material experiences a force resulting from the presence of a magnet or current-carrying conductor. [search on Wikipedia]. The right hand grip rule is used to determine the direction of the magnetic field. The thumbs always indicate the direction of the current, while the fingers indicate the direction of the magnetic field. To determine the direction of the solenoid's magnetic field, the thumbs always point toward the north pole. Also in these experiments we should use this rule to determine the current flow in the solenoid. The strength of the magnetic field can increase by increasing the current, which increases the number of turns of the wire. Substance such as the middle of paper......each finger is perpendicular. The application of electromagnetic induction is direct current generator and alternating current generator. A bicycle dynamo also used this principle to generate the light bulb. In general, Faraday's law states that an induced electromotive force (E) along any closed path in a magnetic field is equal to the speed at which the magnetic flux passes through the path. The first task is to observe Faraday/Lenz's law in action. To observe these laws, simply connect the coil to the multi-galvanometer and see what happens to the electromotive force when the magnet is moving through the coil and also see the deflection of the galvanometer. In this experiment, we also test three types of magnet movements which are stationary, slow and fast and see the deviation of the galvanometer. And we also use 2 different poles of magnet facing the solenoid which are the North and South poles..