Question

Difference between Isothermal and Adiabatic changes.​

Answer 1

Explanation:

If a process is both isothermal and adiabatic, it is implied that the work done on the system is being stored somewhere other than the internal energy of the working fluid. (Or conversely, if the system is doing work, the energy is coming from somewhere other than internal energy.)

Answer 2

Isothermal changes :

1. Temperature (T) remains constant, i.e., ∆T = 0
2. System is thermally conducting to the surroundings.
3. The changes occurs slowly.
4. Internal energy (U) remains constant, i.e., ∆U = 0
5. Specific heat becomes infinite.
6. Equation of isothermal changes is PV = constant.
7. Slope of isothermal curve, $\sf\dfrac{dP}{dV} = - (P/V)$
8. Coeff. of Isothermal elasticity ; $\sf E_i = P$

Adiabatic changes :

1. Heat content (Q) remains constant, i.e., ∆Q = 0
2. System is thermally insulated to the surroundings.
3. The changes occurs suddenly.
4. Internal energy changes, i.e., U ≠ constant. ∴ U ≠ 0
5. Specific heat becomes zero.
6. Equation of adiabatic changes is PVγ = constant.
7. Slope of adiabatic curve, $\sf\dfrac{dP}{dV} = - \gamma (P/V)$
8. Coeff. of adiabatic elasticity ; $\sf E_a = \gamma P$