Electrons in a television's CRT are accelerated from rest by an electric field through a potential difference of 2.9 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?
m/s
(b) The beam is deflected by a perpendicular magnetic field of magnitude 1.03 T. What is the magnitude of the acceleration of the electrons while in the field?
m/s2
(c) What is the speed of the electrons after they travel 4.5 mm through the magnetic field?
m/s
(d) What strength electric field would give the electrons the same magnitude acceleration as in (b)?
V/m
(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?