Look at your unofficial transcript. It that says your previous major, then the official transcript that schools can see will have it. No school will reject you if you changed your major, so don't worry about that.
In my experience, your previous major(s) may show up on your transcript but will not be transcribed to your AMCAS application. Previous majors are sometimes mentioned in a pre-med/committee letter.
If you were taking classes like analog circuitry or solid state hardware your freshmen/sophomore I think the adcom would be able to figure it out themselves.