what if i skipped Com,linear momentum collision rotational mechanics,SHM but read theory and solved PYQ and mastered in MP and optics will i be able to crack iit jee 2021?

Hello student It's not preferable to skip any topic specially in physics because if you skip any topic its very difficult to understand and solve the question, because a single question required multiple concepts and various formula and if you read only theoretical knowledge it won't help you much you need to practice as much as you can so please don't skip any chapter/topic.

You've enough time just prepare each and everything and practice from any good practice Book. You can also subscribe to careers360 knockout package for preparing and qualifying the entrance examination, it offer you 100 percent money back guarantee if you do not qualify.

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https://learn.careers360.com/knockout-jee-main-april/
Feel free to comment if you have any doubt
Good luck