Electrons in a television's CRT are accelerated from rest by an electric field through a potential difference of 2.5 kV. In contrast to an oscilloscope, where the electron beam is deflected by an electric field, the beam is deflected by a magnetic field.
(a) What is the speed of the electrons?
(b) The beam is deflected by a perpendicular magnetic field of magnitude 0.80 T. What is the magnitude of the acceleration of the electrons while in the field?
(c) What is the speed of the electrons after they travel 4.0 mm through the magnetic field?
(d) What strength electric field would give the electrons the same magnitude acceleration as in (b)?
(e) Why do we have to use an electric field in the first place to get the electrons up to speed? Why not use the large acceleration due to a magnetic field for that purpose?