4013. Which of the following equations is obtained on combining 1st and 2nd law of thermodynamics, for a system of constant mass? September 7, 2025 by Admin A. DE = Tds – PdV B. DQ = CvdT + PdV C. DQ = CpdT + Vdp D. Tds = dE – PdV ✅ The correct answer is option A.
