A long cylindrical conductor of radius R = 3cm carries a uniformly distributed current, I, through its cross section, perpendicular to the plane of the paper. The magnetic field, B, at a distance r = 8 cm from the axis is 35 uT in a clockwise sense.
A) how large is the current?
B) How large is B at r = 1cm?
C)how large is B at r = 5cm?