13. Consider the slab of conductive material depicted in the image below with dimensions L = = 6 cm, w = 2 cm, and d = 0.75 mm as shown. A potential of 3 mV is applied along the length, L (between parallel w x d faces), driving current in the direction shown in the image. The measured current through the material as a result of the applied voltage is I = 73 mA. Assume that only electrons contribute to conduction in this material. If a magnetic field B = 7.12 T is applied in the direction normal to the current and the magnitude of the resulting transverse voltage is measured as V = 230 mV, what is the concentration of charge carriers in this material? B Current L Magnetic field W VH