Please solve this quetion in details. Thanks so much in advance.

A certain cylindrical wire carries current. We draw a circle of radius r around its central axis in Figure (a) to determine the current i within the circle. Figure (b) shows current i as a function of r2. The vertical scale is set by is = 5.1 mA, and the horizontal scale is set by r,2 = 4.7 mm2. (a) Is the current density uniform? (b) If so, what is its magnitude? (a) i (mA) 0 r2 (mm?) (b)