Question

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.

Using Drude model, derive an expression for the total excess kinetic energy, K, carried by the electrons in the copper wire in terms of N, l, V, I, and n. (Note: The mobile charges in copper are made of electrons with charge e and mass me.) First, justify that the linear contribution in vd to K is zero, and the only contribution to K is proportional to (vd)2.

en, express the kinetic energy in a product form containing (N/l)2I2V with everything else as a pre-factor, in a similar format as the magnetic energy you need to provide all the justification for each step taken and reduce the final expression to the simplest form possible. Also, pay attention to possible confusion between the charge carrier density and number of winding per unit length and the latter is simply nl=N/l.}

Answer 1