Here are my notes for the course series: Circuits and Electronics, offered by MITx.
Instructor: Anant Agarwal
A computational approach can be found for most problems. I use Mathematica to perform calculations and produce some interesting plots. Many problems have a guide, some helpful material that was in the comments section, textbook or lectures.
The notebooks are also converted to pdf, so one doesn't need a paid software license just to view the solutions. I used the export tool directly from within Mathematica, so this explains any artifacts (images that are truncated at pdf page boundaries, etc).