Took my 1st exam (also GK) yesterday (88%)
The five questions that caught me out were:
i) L/H zero ammeter gauge is indicating zero. Answers ranged from carrying out pulling and re-setting c/b's, or loading up electrical services to see what happens etc. I opted for a answer similar to 'Leave the system alone, the gauge is indicating zero, therefore a failed alternator' Perhaps the question was suggesting that some in flight diagnostics be carried out?
2) Fuel flow gauge indicates high reading. Can't recall to any degree of accuracy what the answers were but it ranged from a combination of pressure 'high or low', fuel flow 'high or low'. I chose fuel pressure would increase, and flow would decrease.
3) An ASI calibration chart in the cockpit shows differences between IAS and CAS. Explain the differences between them. Answers were again combinations of CAS either calibrated for - pressure or density and TAS again calibrated for - pressure or density, IAS instrument errors etc. I couldn't recall seeing much in the theory book on this subject matter however, the question is in the ASL pool. Post #7 on this link looks helpful in trying to remember:
www.atpforum.eu/showthread.php?t=6949
4) A magneto is positioned to 'Left' with no drop in RPM, then positioned 'Right' resulting in dead-cut. I'm sure this was just a case of me forgetting the selection of whichever mag, earth's the other!
5) What is a fuel booster pump for? I chose 'To support the engine driven pump'. I can't recall if one of the answers may have been to prevent cavitation or not? Either way it doesn't change the outcome of my result.
I had all of 'Neville75's' questions (except centre zero ammeter), as well as a few hydraulic questions thrown in.
As Neville75 suggests, go through Bob's questions and you'll be well prepared.
Performance next...