Dear Sir,how to study very effectively to top in 11th and 12th science stream ?
If you want to top only then studying NCERT BOOKS thoroughly would be enough for you.You have to practice a lot of numerical to strengthen your physics and chemistry.Practice a lot from NCERT but first of all make notes of important concepts and formulas which can be used for revision at the time of exam.
Good luck.

It will help you alot in physics.