Which is the proper term to use when talking about circuits in physics—"electrical circuit" or "electric circuit"?
Unlike the first answer, I disagree and feel that "electrical circuit" is correct. Electric does refer to things that run on electricity but circuits are not things that run on electricity like cars, irons, cell phones, toasters, TVs, etc.
We say "electrical engineer" and not "electric engineer" because electrical is an adjective used to describe things related to electricity. We say "electric" car because the car runs on electricity. We say "electrical storm," for the same reason--electrical describes the storm.
So getting back to the question, I feel it should be electrical circuit because electrical is describing what kind of circuit, not that it runs on electricity.
However if you look on the Internet, everyone seems to have an opinion, and searching on Google will give you answers that support any argument. This link may help you see where I'm coming from http://www.dummies.com/how-to/content/what-is-the-difference-between-electronic-and-elec.html
Philip Oakley wrote a song called "together in electric dreams." I suppose dreams run on electricity. Maybe it should have been electrical dreams but that doesn't sound as cool.
Both of them are correct, but there is a subtle difference there.
Electric refers to something that runs on electricity; for example, an electric car, electric kettle, electric circuit.
Electrical refers to something related to electricity, i.e. electrical engineer, electrical component, electrical circuit.
For example, see this excerpt from the Wikipedia article on electrical circuits:
An electric circuit is a path in which electrons from a voltage or current source flow. Electric current flows in a closed path called an electric circuit. The point where those electrons enter an electrical circuit is called the "source" of electrons.