Acurrent i flows through a rectangular bar of copper with cross sectional area a, length l, density p, molar mass m and conductivity o. a uniform magnetic field b is applied perpendicular to the direction of current flow (a) make a drawing of this situation, clearly indicating locations where there is an accumu or negative charge. find an expression for the resulting induced electrical field eind in terms of b, the electron charge e, and relevant properties of the copper bar [12 marks lation of positive (b) find an expression for the ratio of egnd and the electric field associated with the current ecur. estimate this ratio if a = 3.75 x 10-4 m2, / = 0.20 m, b 0.10 t, p 8.96 g/cm3, 63.54 g/mole, and o = 5.92 x 107 a/v. m [6 marks (c) determine the poynting vectors associated with eind and ecur, and estimate the corre- sponding stored electromagnetic linear momentum 9 marks] (e) what do you expect the linear momentum associated with the motion of charges in the 3 marks system to be, and why?