3. An unneutralized electron beam has density n. = 1014m-3 and radius a = 1cm. It flows along a 2-Tesla magnetic field in +z direction, as shown in the following figure. Answer the following questions. [20 points] (a) What are the electric filed magnitude and direction? The electric field occurs due to the beam's charge (use the Gauss's law and divergence theorem) (b) What are the ExB drift direction and magnitude? %3D |2a