Refer to figure `DeltaU_(1)` and `DeltaU_(2)` be the changes in internal energy in the system in process `A+B` and `DeltaW` be the net work done by the system in the process `A+B`,

Options

A. `DeltaU_(1)+DeltaU_(2)=0`
B. `DeltaU_(1)-DeltaU_(2)=0`
C. `DeltaQ-DeltaW=0`
D. `DeltaQ+DeltaW=0`

Answer

A, C

Explanation

For a cycle process, `Delta U=0`
i.e., ` Delta U= DeltaU_(1)+Delta U_(2)=0`
From relation `DeltaQ=DeltaU+ DeltaW`
As `DeltaU=0`
Hence, `Delta Q=DeltaW `
or `Delta Q-DeltaW=0`