Hello!

If you are preparing for an exam like JEE, you must not only study hard but study smart as well. Here are some tips to help you-

• Schedule time for all three subjects (Physics, Maths and Chemistry) daily. 
• Solve previous years question papers and model questions. Identify your weak links and pay more attention to that subject. 
• Practice daily and study with full concentration. Do take regular breaks in between.
  
• You probably have a couple of extra subjects in school also. Devote half an hour per day to them as well.

Assuming you don't attend any coaching, here's a little help to draft a timetable for yourself. After returning from school, relax for an hour then start studying with your mind afresh. Start with the subject you find the moderately difficult. Take a short break after an hour or two and then study what you find the easiest. At night, take the subject you have the most trouble with and solve sums patiently. 

All the best!