Question

Write mathematical equations of first law of thermodynamics for the following processes :
(a) Adiabatic process (b) Isochoric process

Answer 1

(a) In adiabatic process, there is no exchange of heat thus $q=0$. So First law becomes $\Delta U=W$.

(b) Isochoric process, as it is carried in closed vessel $\Delta V=0$ thus $W=0$. So first law becomes $\Delta U=q$.