1. The problem statement, all variables and given/known data A solenoid has a radius of 10 cm and a length of 50 cm. What I need to know to begin the problem is the number of loops ion the solenoid. 2. Relevant equations 3. The attempt at a solution One turn will have a length of 2(pi)r. I need to know the thickness of the wire around. Once I have this I can take the length of the solenoid and divide it by this thickness to obtain the number of turns. I'm just not sure how to go about doing this. Help appreciated. Thanks.