The electron beam emerging from a certain high energy electron accelerator has a circular cross section
of radius 1.00 mm. (a) The beam current is 8.00 uA. Find the current density in the beam assuming it is
uniform throughout. (b) The speed of the electrons is so close to the speed of light that their speed can
be taken as 300 Mm/s with negligible error. Find the electron density in the beam. (c) Over what time
interval does Avogadro's number of electrons emerge from the accelerator? Avogadro's number =
6.02 x 1023 e/mol.