.13 A strip of copper 150 um thick and 4.5 mm wide is placed in a uniform magnetic field B of magnitude 0.65 T, with B perpendi- cular to the strip. A current i = 23 A is then sent through the strip such that a Hall potential difference V appears across the width of the strip. Calculate V. (The number of charge carriers per unit vol- ume for copper is 8.47 X 1028 electrons/m3.)