**Thermodynamics topic questions and answers for interview, campus placement, competitive examination and entrance test.**

You are viewing the first 10 short questions and answers on the thermodynamics topic on this page.

**What is the difference between heat capacity and specific heat of the material?**

*material’s heat capacity*is the amount of heat transformed to raise the unit mass of a material 1° in temperature.

The *specific heat of a material* is the ratio of the amount of heat transferred to raise the unit mass of a material 1° in temperature to that required raise unit mass of water 1° of temperature at some specified temperature.

For most engineering purposes, heat capacities may be assumed numerically equal to specific heat values.

**Explain the rule to find specific heat for aqueous solutions.**

**What do you understand by latent heat? Give examples of latent heats.**

*latent heat*. Examples of latent heat are the heat of fusion, vaporization, sublimation and change in crystal form.

**Define the term free energy and free enthalpy. What are their significance and importance?**

It is equal to the work during a constant-volume isothermal reversible nonflow process.

Free enthalpy (or Gibbs function) is defined as

g = h – Ts

(where u = internal energy, h = enthalpy, T = temperature, s = entropy)

Gibbs’s function is of particular importance in processes where chemical changes occur. For reversible isothermal steady-flow processes or for reversible constant-pressure isothermal nonflow processes, change in free energy is equal to network.

**What is the polytropic process? Under which conditions do polytropic process approaches isobaric, isothermal, and isometric processes? In which reversible process no work is done ?**

^{n}= constant (‘p’ is the pressure, ‘v’ is the volume and index ‘n’ may have values from -∞ to +∞. This process approaches isobaric when n = 0, isothermal when n = 1, and isometric when n = ∞. No work is done in the isometric process.

**Out of constant pressure and volume lines on the TS diagram, which line has a higher slope? and whether the slope is constant or variable ?**

**In which process fluid expands but no work is done?**

**Whether superheated steam can be treated as an ideal gas ?**

**Which parameter remains constant in isochoric process ?**

**In which process internal energy remains constant ?**