Lessons In Electric Circuits
Socratic Instrumentation Project. - If you are interested in industrial instrumentation, Checkout the book "Lessons in Industrial Instrumentation" at the Socratic Instrumentation project. The project provides work sheets too. You will also find links to public-domain textbooks on subjects related to industrial instrumentation.
"We live in a world where the accumulation of knowledge is exponential over time, and where the ability to continuously learn and make sound judgments is essential to survival. Formal education ought to play an important role in preparing individuals to succeed in this environment, but many traditional modes of education actually discourage development of independent thinking skills necessary for success."
" The most important thing any educator can impart to a student, in any context, is the ability to teach themselves." - Tony R. Kuphaldt