A thermodynamic process is shown in Fig. The pressures and volumes corresponding to some points in the figure are : `P_(A) = 3 xx 10^(4) Pa, P_(B) = 8 xx 10^(4) Pa` and `V_(A) = 2 xx 10^(-3) m^(3) , V_(D) = 5 xx 10^(-3) m`.
In process `AB, 600 J` of heat is added to the system and in process `BC, 200 J` of heat is added to the system. The change in internal energy of the energy of the process `AC` would be.

Options

A. 560 J
B. 800 J
C. 600 J
D. 640 J

Answer

A

Explanation

`DeltaQ_(ABC)=DeltaQ_(AB)+DeltaQ_(BC)=600+200=800J`
`DeltaW_(ABC)=DeltaQ_(AB)+DeltaQ_(BC)=0+P_B(V_D-V_A)`
`=8xx10^4(5-2)xx10^-3`
`=240J`
`DeltaU=U_C-U_A`
`DeltaQ=DeltaU+DeltaW`
`800=DeltaU+240impliesDeltaU=560J`