Question

Given a solenoid of total number of windings, N, of length, l, and circular cross sectional area, A. A current, I, is flowing through the wire winding that is made of copper. Assume that the copper has a resistivity p and the charge carrier density, n. Assuming that the winding wire is circular in shape with a cross-sectional area, a, and the adjacent wires are closely spaced together so the wire diameter is simply d=l/N. The volume of solenoid space is V=pi * A^2*l/4. Derive an expression for such a solenoid relating to the drift velocity, v sub d, to the current I, winding number N, carrier density n, and volume of the solenoid V=Al.

Answer 1