Find the drift speed of electrons in a 10-gauge copper wire carrying a 20A current. (area of wire =5.261mm2, density of copper = 8.93g/cc, atomic weight = 63.5g/mole, one conduction electron is donated by each atom.)
In a proton accelerator, the energy of proton is 20MeV, the diameter of the beam is 2.0mm, and the beam current is 1.0mA. Find the current density and the particle density in the beam.