Hi . Physics is not ur major subject so check its syllabus first . If u think the topics are of ur interest than go for it. Personally i think physics is hard nut to crack .
Usually people opt for the subjects that are marks gaining and are short in syllabus .
Do some research on other subjects u may consider of ur interest other than physics.
Css is a very individualistic exam, so do some introspection and judge your current standing with the preparation.

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