AoA,
Just back from my interview of Lecturer Microbiology, there were 3 people sitting in the committee, Chairman(old guy looks friendlier tho), Subject expert(thats ur course), and third guy was a Islamiat and General knowledge expert.

he asked things like,
1. what is other name of Korti Barrage?
2. how many canals arise from this Barrage?
3. what is title of Hazrat Adam A.S and also of Hazrat Nooh A.S.
4. Name the person who got noble prize in Pak, and...what subject did he got it for.

No demonstration was asked from me.
There were interviews for another post, i asked a guy he said we had to give little demo/ presentation. so yea it depends on person to person.

Note: in ur interview letter they tell us what subjects u have to study for interview.