Which reactor has no moderator ?

Fast breeder reactor.

In which process fluid expands but does no work ?

Throttling process.

Whether entropy is intensive property or extensive property ?

Entropy is extensive property.

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

Constant volume line. Slope is variable.

Define the terms free energy and free enthalpy. What is their significance and importance ?

Free energy (or Helmholtz function) is defined as/= u -Ts.
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 net work.

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

For pure substances, the heat effects accompanying changes in state at constant pressure (no temperature change being evident) are known as latent heats. Examples of latent heats are : heat of fusion, vaporisation, sublimation, and change in crystal form.

Explain the rule to find specific heat of aqueous solutions.

For aqueous solutions of salts, the specific heat can be estimated by assuming the specific heat of the solution equal to that of the water alone. Thus, for a 15% by weight solution of sodium chloride in water, the specific heat would be approximately 0.85.

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

The heat capacity of a material is the amount of heat transformed to raise unit mass of a material 1 degree in temperature.
The specific heat of a material is the ratio of the amount of heat transferred to raise unit mass of a material 1 degree in temperature to that required to raise unit mass of water 1 degree of temperature at some specified temperature.
For most engineering purposes, heat capacities may be assumed numerically equal to;specific heats.

What is Bauschinger effect ?

According to Bauschinger, the limit of proportionality of material does not remain con¬stant but varies according to the direction of stress under cyclic stresses.

What are whiskers ?

Whiskers are very small crystals which are virtually free from imperfections and dislocations.

What is temper embrittlement in alloy steels and what are its effects ?

Embrittlement attack is usually intergranular in metals, i.e. cracks progress between the grains of the polycrystalline material. It imparts a tendency to fail under a static load after a given period of time in those alloy steels which are susceptible to embrittlement.