MANUFACTURE A DEVICE TO SURVEY E.M.F IN A COIL PLACED IN THE MAGNETIC FIELD OF A MAGNET

Abstract

Electromagnetic induction is an important part of Physics knowledge taught at most technology and engineering universities in Vietnam, including Hanoi University of Industry. The survey shows that the number of experiments on the phenomenon of electromagnetic induction taught at universities in Viet Nam is almost non-existent or very small. Therefore, with the desire to research and create a device of experiments on electromagnetic induction, the authors conducted theoretical research combined with experimental research to create device of experiments to survey electromotive force induction in a coil placed in the magnetic field of a magnet. The results of investigating the dependence of the induced electromotive force on the parameters: rotation speed of the magnet, number of turns in wire coil, cross-section of the coil show that: the amplitude U_out depends linearly on the rotation speed of the magnet (coil with size d=42.44 mm, N=200 turns); the more turns of wire coil, the larger U_out (coils with diameter d=51.9 mm and different numbers of turns 50, 100, 200, 300) However, with the dependence of U_out on the cross-sectional area of the coil, when increasing the cross-sectional area U_out also increases, but increasing to 2114.48 mm², U_out tends to decrease. Especially when increasing to 4837.37 mm², the decrease speed of U_out is shown very clearly.