Hello Aspirant
You can access Previous Year's Question papers via the Internet or via Guidebooks. Guidebooks like Pearson's, Gupta's, etc. are the good ones.
Here are some links for the websites that have the PYQs- https://questions.examside.com/past-years/jee/jee-main/physics/heat-and-thermodynamics
https://engineering.careers360.com/exams/jee-main/thermodynamics-practice-question-mcq
https://engineering.careers360.com/exams/jee-main/introduction-to-thermodynamics-practice-question-mcq
Hope this helps
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