I go to a school ranked 150ish and ive realized that the prelims so far have been very hard. This is based off the 2019 past paper i did as practise from a whole range of schools. The past papers weren't that difficult compared to the exams my school gave me. I know that the pressure of the acutal exams may have made it seem harder? Im not sure. Does anyone know why schools would do that?
I'm in the same boat, I had a Chemistry exam yesterday. The past papers we had done from my school from 2018 and 2019 were respectively a joke and significantly easier than that of the paper I had to do. In fact the paper I did was probably twice or 3 times as hard as the past papers we had done.
Of course, pressure of exams may make it seem harder but it all really boils down to what's on the paper. Maybe it was hard because there were particular things you didn't study hard enough etc. although in your defence it is reasonably hard to predict what actual tests will have based on past papers unless there is a common trend within all past papers (e.g. galvanic cells for chem past papers).
That being said perhaps its a good thing that they are harder even if students don't perform well because it gives everyone a taste of how hard trials are probably going to be. It may also be treated as a feedback thing for teachers as to which specific areas they need to teach more carefully or reinforce constantly to future senior students (but i doubt that last point is actually the case)