The Hall effect can be used to calculate the charge-carrier number density in a conductor. A conductor carrying current of 2.0 A is 0.50 mm thick, and the Hall voltage is 4.5 x 10-6 V when it is in a uniform magnetic field of 1.2 T. What is the density of charge carriers in the conductor? a) n = 4.6 x 1027 charges/m b) n = 1.7 x 1027 charges/m c) n = 1.0 x 1028 charges/m d) n = 6.7 x 1027 charges/m²