This is the Lorentz force with which the electromagnetic field acts on a point charged particle. It also works not only in picture tubes, but also in charged particle accelerators, electric motors, mass spectrographs, and magnetrons. It was discovered by the Dutch physicist of the 19th and 20th centuries, Hendrik Lorenz, a Nobel Prize laureate, who made a number of significant discoveries in the field of electrodynamics and optics. In particular, he predicted the existence of an electron, the splitting of spectral lines in a magnetic field, and substantiated the dependence of the electrical conductivity of a substance on thermal conductivity.
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