Question

$\Delta E=0$, for which process?

• A. Cyclic process
• B. Isothermal expansion
• C. Isochoric process
• D. Adiabatic process

Answer 1

Answer: (A), (B)

Cyclic process
Isothermal expansion

$\Delta E=n{C}_V\Delta T=q+w$

For cyclic process, $\Delta E=0$ as it is state function.

For isothermal expansion, $\Delta E=n{C}_V\Delta T=0$

because $\Delta T=0$

For isochoric process, $\Delta V=0$

$\Rightarrow w=0$

$\Rightarrow \Delta E=q$

For adiabatic process, $q=0$

$\Rightarrow \Delta U=w$