Question 454: Thermodynamics & KTG

Question

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

Accepted Answer

In cyclic process, change in total internal energy is zero.
$$\Delta {U_{cyclic}} = 0$$
$$\Delta {U_{BC}} = n{C_v}\Delta T = 1 	imes {{5R} \over 2}\Delta T$$
where, $${C_v} = $$ molar specific heat at constant volume.
For $$BC,$$ $$\Delta T =  - 200\,K$$
$$	herefore$$ $$\Delta {U_{BC}} =  - 500R$$

Answer

The change in internal energy in whole cyclic process is $$250$$ $$R.$$

Answer

The change in internal energy in the process $$CA$$ is $$700$$ $$R$$.

Answer

The change in internal energy in the process $$AB$$ is - $$350$$ $$R.$$

Answer

The change in internal  energy in the process $$BC$$ is - $$500$$ $$R.$$

Thermodynamics & KTG

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

Choose the correct answer: