PHYS 1B Lecture 19: Magnetism
Document Summary
Often, electric fields and magnetic fields will both exist in a region of space. Here, both an electric and magnetic force will act on a moving charged particle. The sum of these forces is called the lorentz force. The configuration of fields in the figure is commonly used as a "velocity selector" The two forces act in opposite directions on the particle, so for a particular electric field and magnetic field strength combination, there will be exactly one velocity at which the two forces exactly cancel. The velocity selector serves at a first stage in a mass spectrometer. In the second state, a magnetic field curves the charged particle into a circular path whose radius depends on its mass to charge ratio week 8 page 1 depends on its mass to charge ratio. Recall, we previously calculated the radius of the circular path.