I have detailed my interview questions at another thread in this forum. Here is its link:

CSS Forums - View Single Post - CE 2010 interviews.



Apart from that, I would advise the following to be kept in mind for Interview:
- Be very concise and clear in your answers. No one appreciates lengthy stories. I would say, an answer should hardly exceed a sentence or two.
- Do not be intimidated by the initial general knowledge type questions shot at you (name of president of X country, location of Y river etc). In my personal opinion these questions are merely there to bring you under pressure so as to judge your responses under that frame of mind. They have no bearing whatsoever on your interview performance. I said sorry to all 4 such questions asked to me.
- Do not be afraid to take a stance on an issue, if you have a clear argument about it. Treading a middle line shows your weakness, and not your diplomacy skills to opt for a middle path.
- However, in the psychological assessment, you should adopt a moderate line both while answering different personality based questions and during the group discussions. Try to bring out the positive in you and be optimistic about things. Trust me, the FPSC makes sure, they select moderate liberal and optimistic personalities for recruitment to Civil Services. At least this is what I can safely say about 190 odd probationers in the 39 Commons.
- Your selection of personalities and favourite books should be in sync with your own personality. This means, the personality you refer to as your idea, his reflection should be visible in your own self and character. For instance, if you admire social work, you should not opt a pop singer as your favourite personality.

Rest, offer regular prayers, read newspaper diligently and think through your different motivations to join Civil Services and your preferred occupational group. You will be thoroughly asked from these areas.

Best of Luck!