like stantheman said, those reports really helped me pass this time (failed in december)
you need to digest GN3 as they only want the answers from that book, not wot you already know or a mate said. i failed to put enough detail into my answers and assumed they would already know the circuit was isolated before testing, well that didnt help. its impossible to tell you wot to expect, just go over GN3 but make notes each time you do, i find re writing it as i read it helps it go in??!!
as it says in those chief examiners reports, try to allow enough time for the larger pointed questions, and dont sit dwelling on a 2 pointer, for ages. say 15 mins for 15 points, 2 mins for 2.
good luck mate