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

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

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

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

The *specific heat of material* is the ratio of the amount of heat transferred to raise 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 of the 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 heats*. Examples of latent heats are the heat of fusion, vaporization, sublimation and change in crystal form.

**Define the term free energy and free enthalpy. What is 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 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 polytropic process approaches isobaric, isothermal, and isometric process? 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 constant volume lines on TS diagram which line has 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 like ideal gas ?**

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

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