1. The problem statement, all variables and given/known data You have 12m of 0.50mm diameter copper wire and a power supply capable of passing 17A through the wire. What magnetic field strength would you obtain inside a 2.0-mm-diameter solenoid with the wire spaced as closely as possible? 2. Relevant equations 3. The attempt at a solution My problem is that I cant find n - tried about 50 times but its always wrong. n=12/(pi*0.0205) wrong n=12/(pi*0.02) wrong n=0.02pi wrong never thought this was right but I cant think of anything else to do??? for a mastering physics online question so no answer yet.