UTC Aerospace Systems Graduate Engineer Trainee interview questions

It was a single interview with technical and HR rolled into one. There were three interviewers - while one took the technical interview, the other two went through my resume. The interview process was overall quite good, however I found the interviewers to be somewhat unprofessional in that they were making unpleasant expressions every time I gave an answer they didn't like / was wrong.

Online test Group discussion Technichal+ Hr interview Online test comprises of aptitude, technical questions (branch related), simple coding All multiple choice questions. Group discussion on technichal topic, Topic is given based on branch you belong to. I'm from ECE, I got topic based on control systems.