(a) Adding dopants to a sample of silicon is found to reduce the Hall coefficient by a factor of 10 and increase the conductivity by a factor of 5. What effect has this dopant addition had on the mean free path?
(b) In a Hall experiment with a transverse magnetic field of 20 tesla, the total electric field is at angle 20o to the current. Assuming the charge carriers to be electrons, what is their collision time?
(c) If you doubled the width of a Hall sample but kept J and B the same, how would that affect the Hall field? the Hall voltage? the net charge density along the edges?