27.

28.

29.

30.

31.

32.
33.
34.

35.

3 C 1264

Find the
efficie ~ |

oe iciency of a Carnot's engine working between 127°C and 27°C. It absorbs 80 cals of
580% much heat is rejected?

When 50
8 of water is heated from 10°C to 90°C, by how much does its entropy change ?

Calculate ‘
100°C the specific heat of saturated steam. Given that the specific heat of water at
= ந, n हि
of 0.64 01 and latent heat of vapourization decreases with increase in temperature at the rate
-64 caVK_ Late ,
Latent heat of vapourization of steam is 540 cal.

Fermi energy of conduction electrons in silver is 5.48 eV- Calculate the number of such electrons
per em? given that h = 6.62 x 10-27 erg sec, and 1 eV = 1.62 x 10°? er:
Show that adiabatic curve is steeper than isothermal curve.

(3 x 6 = 18 marks)
Section E (Essays - Answer in about two pages)

Answer any two question.

Each question carries 10 marks.
Derive the two expressions for the work done in an adiabatic process.
State and preve the thecrem of equipartition of energy. Give the merits of this theorem.
Discuss with necessary theory the construction and working of an Otto engine.

Derive Maxwell's four thermodynamic relations. Discuss the usefulness of these relations.

(2 x 10 = 20 marks)