I believe that Singapore does not release the olympiad papers, but from guesswork and other blog posts (esp from NUSH students), about Physics Olympiads, I would expect the format to be similar to the IPhO. IPhO past papers can be found here : http://ipho.phy.ntnu.edu.tw/problems-an ... ons_5.html, and I believe that the practical round will also be 1. Design an expt to obtain ... 2. Do the expt yourself... 3. Data analysis
To study for this, I think that it would be best to study topics like Quantum, Matter, Electricity's theory, and maybe try the APhO practical papers. Expect to be unable to do the paper without lots of practice, but on the bright side, if you can do APhO, you can do SPhO.
I'm not really sure about Bio and Chem, but the format of the paper shouldn't differ too much.
On that note, my son just took the SPhO paper today, and does anyone know when the notification for practical round will arrive? Feeling nervous waiting