1. The problem statement, all variables and given/known data the question can be found here: http://www.mailfreeonline.com/uploader/CED0D65C.jpg [Broken] 2. Relevant equations ampere's law 3. The attempt at a solution a. (is B the magnetic field?) B = uI/L; u = 4pi x 10^-7, I = 1, L = 2pi x 0.1 so B = 2 x 10^-6 ^ can anyone confirm this? b. B = uNI/L (i'm guessing L is the radius this time). i don't know how to incorporate the length of the solenoid into this equation. i don't know the assumption either. c. is this the same as part b but with numbers plugged in?