An electron is accelerated from rest towards the right in the horizontal direction by a potential difference of 400 V. The electron then enters a uniform magnetic field of magnitude 0.2 T directed into the page with its velocity perpendicular to the field.
(a) What are the magnitude and direction of an electric field that will cause the electron to continue to move horizontally? Ignore gravity. The electric field is now removed,
(b) Calculate the radius of the electron's path in the magnetic field.