Your employer asks you to build a 20 cm long solenoid with an interior field of 5 mT. The specifications call for a single layer of wire, wound with coils as close together as possible. You have two spools of wire available. Wire with #18 gauge has a diameter of 1.02 mm and a maximum current rating of 6 A. Wire with #26 gauge is 0.41 in diameter and can carry up to 1 A. which wire would you use, and what current will you need?
