The demonstration of Electromagnetic induction from Faraday's law

Abstract

This research aims to develop a demonstration kit for Faraday's law of electromotive force for high school students. The demo kit is designed to be able to adjust the number of magnets, the number of turns of the coil and the distance between the magnet and the coil. The kit consists of a magnetic disk, 3 piece coils motor and a microcontroller rotation control system. The magnets used are high-intensity, coin-shaped - 2 cm diameter type that mounted on a turntable spaced between the magnets and the coils. The insulated copper wire used is approximately 0.1 millimeters, wrapped in a circular shape with a diameter of 2 centimeters, the numbers of turns are 100 300 and 500 turns. In this experiment,the electromotive force exerted on each coil at the rotation speed of the magnetic disc in the range of 200 – 800 rpm was studied. The results showed that the electromotive force generated increased with the number of magnets and the number of turns of the coil but will decrease with increasing distance. When using 6 bar magnets with 500 turns of the coil at 200, 400, 600 and 800 rpm and a distance of 2 mm, the average electromotive force was 5.7, 27.0, 30.0 and 44.7 millivolts respectively. But when the distance between the coil and the magnetic field was increased to 6 mm. At 200, 400,600 and 800 revolutions the mean voltage was reduced to 0, 0.6, 1.1 and 1.8 mV, respectively. In this studied, the results showed that it was consistent with Faraday's theory of induction. which can be applied as a learning management media for students to replace expensive imports from abroad.