The questions are mostly to check you have a basic understanding of aircraft and the aviation industry; this shows that you have an element of enthusiasm and interest in the subject (for example can you confidently explain how lift is produced, the basic principles of how a jet and IC engine work).
The non-technical side is to see if you have the enthusiasm/ commitment to be able to complete the course and the core competency skills (either already have them or are are in a position to be able to develop them) such as leadership, confidently making decisions and challenging decisions made by others. Explaining the role of the crew on an aircraft, etc...