I wasn't expecting questions about electrical principles, since my position did not involve working directly with the products we sell. If you don't have a technical background and aren't interviewing for a technical position, it's probably okay to admit you don't know the answers. That shouldn't be a deal-breaker, but it might be to your benefit to learn a little about electricity and the products Eaton sells before you interview. This may not apply to other areas, I can only speak for myself.