Current and Resistance

Problem 19:A particular wire has a length ofL=1.23m and a circular cross-sectional area of radiusr=0.18mm.

Part (c) Give an expression for the current density in the wire if an electric field E is passing through it. Respond in terms of the resistivity and the other variables in the problem.

Part (d)Calculate the current in the wire, in milliamperes, if the field strength is 3.05 V/m.