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

Options

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

Answer

D

Explanation

`DeltaU=q+w`
For an isothermal process, `DeltaU=0," "q=-W`
For an isochoric process, `W=0," "DeltaU=q`
For an adiabatic process, `q=0," "DeltaU=W`
For a cyclic process, `DeltaU=0," "thereforeq=-W`