We usually say "electric" to indicate that somthing works by electricity: an electric light, an electric motor. "Electrical" is more general; "electrical goods" may be machines and lights, but also pieces of cable etc. I'ts a category of products. An "electrical engineer"; he is not electrically operated, his business is electricity.
"Electronics" is a specific branch of electricity concerning valves, transistors, diodes rather than machines.
By the way, "difference
between", not "among".