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

Answer

C

Explanation

`triangleU_(CA)=(5)/(3)R[200]`
`triangleU_(AB)=(5)/(2)R[400]`
`triangleU_(BC)=(5)/(2)Rxx-100=-500`