PHY 121 Lecture Notes - Lecture 12: Magnetic Monopole, Electric Generator
11 Dec 2016
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Document Summary
A bar magnet modifies the space around it to create a magnetic field. Magnetic field lines always go from north to south. Magnetic fields exert forces on moving charged particles. When velocity and magnetic fields are parallel then there is no force which means there is no current. When velocity and magnetic field are perpendicular then a force is created which runs perpendicular to the other two vectors. Maximum current occurs when v is perpendicular to b (magnetic lines). Zero current is generated when v is parallel to b (magnetic lines. Frequency is 60 hertz in the usa and typically 50 hertz in europe. Ac generators are used in the usa instead of dc generators. Dc generators lose power too easily, while ac generators do not. Fluctuating current allows for the use of transformer. Voltage is related to the number of turns of the wire. A changing magnetic field gives us an alternating current.
