best case study based questions bank book for cbse science 2021
Hello Aspirant,
I assume you are asking for class 10 science. In that case, the best publishers to refer for practice questions and sample papers are Oswaal, Arihant and Pearson Question bank.But given the NCERT textbooks the first priority as it is the best source . After mastering the basics from NCERT and solving every single problem in it , you may start with the above mentioned publishers books .
These links can be useful :
https://school.careers360.com/articles/best-reference-books-for-cbse-class-10-science
https://school.careers360.com/articles/cbse-class-10-science-sample-papers
All the best