Hi Suresh!

Yes, you are right! NCERT Exampler is really very important for NEET preparation specially for biology and chemistry. Check out some previous year papers and you will see many questions are directly asked from the NCERT Exampler. But there are no fixed number of questions to be asked in NEET from exampler. Also, you can try to solve the exampler for physics as well but do not stress much on it. You can refer to some other books as well for preparation of NEET.

Thankyou!