For example, in the following figure, it makes perfect sense that the AC source Et defines the vector angle of zero:

In the next Chapter on Series RL it is explained clearly why inductor current lags behind voltage but the reference point used in the figure is not-intuitive.

Since Et = El why isn't the AC source voltage phase still the reference point at zero degrees? If displayed this way then the inductor current [tex]I_{L}[/tex] lagging by 90 should be at -90 angle. Leading should be postive anmd lagging should be negative angle with respect to the AC source E and I phases. As I look ahead to more complex circuits, I want to avoid rote memorization and have a more intuitive feel to understanding how mixed circuits work. I must be missing something obvious if these are the teaching standards used? Can anyone offer some advice?

thanks

Jerry K1JOS