Have you ever heard "Electric Field of one turn Solenoid? hi, guys: Have you ever heard "Electric Field of one turn Solenoid"? Here is a example from MIT. Click on the weblink: http://web.mit.edu/6.013_book/www/book.html Click on the Chapter 10 in the left part of the screen! Now Click on 10.1 , which say something about Magnetoquasistatic Electric Fields in Systems of PerfectConductors In the Example 10.1.2, you will find the Electric Field of one turn Solenoid I am confused about this example! First I cannot understand "a circular cylindrical conductor having an inside radius a much less than its length in the z direction" Is this solenoid 3 dimension or 2 dimension? If it is 3 dimension, is it still " solenoid'? Second I cannot agree with the Equation (14), which claims that "the field inside the solenoid is uniform, axial, and equal to the surface current " ?? Anyway, I cannot understand the example at all, does anybody who is a guru in Electrodynamics can understand that?