I'm not sure what the positions you are interviewing for mean, but still being a third year student I would only be interviewing you for an internship/co-op position, definately nothing permanent. Having said that, I would be looking at the technical courses you have taken and see what your depth of knowledge on those subjects is. I wouldn't care to see any schematics, etc, that you would bring in - although I might ask about some of the work experience. Rather, I would likely present you with a scenario that is appropriate to the position in which you are interviewing for and see how you approach it - keeping in mind that you have limited experience. My suggestion to you is to understand the functions of the position that you are interviewing for, research the company, and be honest - if you don't know the answer to something they will know if you're trying to bs through it.