Based on first law of thermodynamics, which one of the following is correct ?

Options

A. For an isochoric proces`,DeltaU =-q`
B. For an adiabatic process, `DeltaU = -w`
C. For an isothermal process`,q= +w`
D. For a cyclic process,`q= -w`

Answer

D

Explanation

(a) `DeltaU = q+w`. For an isochoric process, `w = - P DeltaV =0`. Hence,`DeltaU = q_(v)`
(b) For an adiabatic process , `q=0`. Hence, `DeltaU =w`
(c ) For an isothermal process, `DeltaU =0` Hence, `q=-w`
(d) For a cyclic process , `DeltaU =0`. Hence, `q= - w`