Ampère's law is usually used to find the magnetic field given a current distribution, but it can also be used to find the current given a magnetic field. d the magnetic field shown has a constant magnitude of b, from y 0 to y and is directed out of the page. it has zero magnitude everywhere else. a. where in space is there current? explain. (hint: consider all regions, as well as the boundaries between regions). describe the current distribution. is it a volume current density, a surface current density, or a line current? y=0 y=d where there is non-zero current, describe how you could use ampère's law to find the t density. what ampèrian loop would you choose, and where would you put it? b. where the current density is non-zero, determine its magnitude and direction. express your answer in terms of b, and check your units (volume current density has units of current per area, and surface current density has units of current per length). 2. challenge question (not graded, based on the tutorial supplement in ampère's law). reconsider the square ampèrian loop for the square infinite wire. a. suppose you were given the magnetic field at points a and b. would this be enough information to solve for the current density? explain. uniform current into the page b. suppose you were given the line integral of the magnetic field from point b to point c. would this be enough information to solve for the current density