Main Question or Discussion Point
The standard explanation is that the magnetic field stores the energy but when I start considering different sizes of a single loop inductor with a current flowing in it things start to get a bit vague. As the loop diameter is increased the inductance goes up so the single loop can store more energy. At small diameters the magnetic field across the loop is a reasonable value but if the loop was 1 mile across or 100 miles it is difficult to see how any part of the loop is any different to a straight piece of wire that doesn't have inductance. Is it the case that a straight piece of wire stores energy in its magnetic field when current flows?