May I be so bold? There is no difference in meaning between electric and electrical. Both are words that describe electricity, circuitry, charge, ions, etc. - all the physical stuff. 'Electronic' more aptly describes appliances - things that use electricity. Hope that helps.
Dave, I think you're probably spot on. In my opinion, electronic is an older and more outmoded term. I would ask whether electrical and electric are interchangeable terms, and that in fact the former is used in a more 'high-brow' way or at times when a little more credence could be given to a term? ELECTRIC ENGINEERING sounds naff, but ELECTRICAL sounds better.
Electronic refers to what is known as solid-state electrics, using printed circuit boards instead of conventional wires, microchips, lower voltages etc. A computer is a prime example of something electronic (in other words, miniaturised). Electric means simply powered by elecricity. Many electric products incorporate electronics, such as an electric washing machine where electronics work the programme, telling the motor when to turn, the heater to switch off, and so on.