But the point of having a list of questions is that you dont expect a candidate to know all of them. You should make that clear up front so that a candidate does not feel flustered if they dont know something.

If you make a test and you expect someone to answer everything then your test has to either be way too hard or way too easy. Remember in school those tests that were really hard and the highest 'uncurved' grade was a 60%? Those are awesome tests.

Why are they awesome? Because it opens up the range of a candidate to see where they are at in their career and development.