1. The problem statement, all variables and given/known data A solenoid is wound with a single layer of copper wire of radius 0.38 cm. The solenoid is 4.5 cm in diameter and 3 m long. What is the inductance of the solenoid per unit length? Assume that adjacent wires touch each other and that insulation thickness is negligible. radius of copper wire = 0.0038 m length of solenoid = 3 m diameter of solenoid = 0.045 m 2. Relevant equations L = ([tex]\mu[/tex] * N^2 * A)/l where L = inductance [tex]\mu[/tex] = 4*PI*e-7 (perm. of free space) N = number of turns A = cross sectional area l = length of the solenoid 3. The attempt at a solution by working backwards, i figured the number of turns = 3/2*[tex]\Pi[/tex]*0.0038, but its not working out any help?