Homework 7.3 A long cylinder of radius R carries a uniform surface current with density Ko flowing down its axis. Using the Biot-Savart law to find the magnetic field inside and outside the cylinder. What is the total current flowing on the cylinder? How does the field outside the cylinder compare with that of a straight line current? Hint: Without the loss of the generality, one can set up a coordinate system such that the cylindrical axis is the z-axis and the point of interest is on the x-axis. You may find the following integral useful . 2 7T (r - Rcos d) r - R do 1 + r2 + R2 - 2r R cos r - R