CBSEJEENEET
Thermodynamics First Law: Sign Convention for Q, W, ΔU
Finally clear heat, work, and internal energy for boards and JEE.
Dr. Alex Mitchell2025-02-1714 min read
PV Diagram Process
Key relation
ΔU = Q − W
Work as Area on PV Curve
First Law Thermodynamics
First Law Thermodynamics is a core physics topic for competitive exams. Study the formulas, practice numericals, and review key concepts.
Try interactive calculators
Frequently Asked Questions
Is compression positive or negative work?
Compression: volume decreases, work done ON gas, W is negative in ΔU = Q − W convention (work by system negative).