Magnetic Force As with electric fields, magnetic fields can exert force on charged particles such as protons and electrons. The force is ! F = q ! v ! ! B where q is the charge on the particle in coulombs, ! v is the particle’s velocity vector in m/s, and ! B is the magnetic field vector in teslas. This equation immediately makes it clear that not only does a magnetic field exert no force on an uncharged particle, but it also exerts no force on a charged particle that happens to be at rest, or that is moving directly with (parallel to) or directly against (anti-parallel to) the magnetic field itself. As usual, this cross-product can be written F = q|v||B| sin θ where θ is the angle between the velocity and field vectors. To find the direction of the force, a special version of the Right-Hand Rule can be used. It is shown in the diagram to the right. The right hand is held flat with the thumb extended outward. The fingers are oriented so that they point along the (presumably straight) magnetic field lines from south to north,
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This note was uploaded on 04/05/2012 for the course PHYS 131 taught by Professor Tibbets during the Spring '11 term at Cuyamaca College.