One mole of a diatomic ideal gas undergoes a cyclic process ABC as shown in figure. The process BC is adiabatic. The temperature at A,B and C are 400K, 800K and 600K respectively. Choose the correct statement:

Options

A. The change in inetrnal energy in whole cyclic process is `250R`.
B. The change in internal energy in the process `CA` is `700R`
C. The change in internal energy in the process `AB` is `350R`
D. The change in internal energy in the process `BC` is `500R`

Answer

D

Explanation

`DeltaU = (f)/(2)nR DeltaT`
For cyclic process `DeltaU = 0`
For process `CA`
`DeltaU = 1 xx (5)/(2) R(-200) =- 500R`
For process `AB`
`DeltaU = 1 xx (5)/(2)xx (+400) = 100R`
For process `BC:-`
`DeltaU = 1 xx (5)/(2) R xx (-200) =- 500 R`