physics pass 3rd sem 2016 question paper. | Assam University

physics pass 3st sem 2016 question paper. | Assam University

TDC Odd Semester Exam., 2016 

PHYSICS 

Pass 

3rd Semester 

Course No. PHSP-301 

(Heat and Thermodynamics-)

Full Marks : 35 

Pass Marks-: 12 

The figures in the margin indicate full marks for the questions 

Answer five questions, taking one from each Unit 

UNIT-I

1. (a) Describe the construction and working principle of platinum resistance thermometer. 243e5
(b) Mention one advantage and one disadvantage or this thermometer. 2

2. (a) Distinguish between the specific heat or a gas at constant pressure and at constant volume. Show that for an ideal.
(b) How do you determine specific heat at constant volume (Cv or a gas by using Jalys differential steam calorimeter? 3

UNIT—II

3. (a) Describe Andrews Experiments carbon dioxide. Discuss the results dfined by him.
(b)state the law of corresponding State. 1

4. (a) What are the assumptions of kinetic theory of gases? Prove by kinetic theory of gases thet the pressure exerted b’ a a is given by p!2n where is the root-mean-sluare velocity cf gas molecule and p is -.he density of gas. 2+3—s
(b) Derive an expression for the mean path of the molecules of a gas 2

UNIT—Ill 

5. (a) what do you mean by (1) variable state, ii) steady state and (iii) thermal diffusivity? I + 1+1 ‘3
(b) Define coefficient of thermal conductivity. Mention its units and dimension. 1+1+1=3
(C) What is rectilinear flow of heat? 1

6. (a) Describe lnsen-Kawiz experiment b compare the thermal conductivity cf different materials. 4
(b) In an Inger-Haus experiment, wac melted orer 10 cm of copper rod an:1 over 4 cm of non rod What is tbe conductivity o iron when t1 conductivity f pper is o)0? 3

UNIT—IV 

7. (a) Using the 3rd law of thermodynamics, deduce the relation pV constant where the symbols have their usual meanings. 4
(b) Find the efficiency of a Cainot's engire working between 127 °C and 27 C. ft absorbs 80 calories of heat How much heat is rejected

8. (a) Define entropy. what is its physical significance? 1.2=3 rb Explain how entropy change. during reversible process 2
(b) State the second low thermodynamic.

UNIT-V

9. (a) what is a perfect blackbody? Describe the experimental curve or blackbody radiation. 1.4-5
(b) hm°hT 2

10. (a)State and explain Stefan-Boltzmann law of radiation. CakWwic the radinted per mnlnutr from the filuinisit ci an incandescent limp at 200o K if the area is S xl O sq. meucs and its relative emtanee is 0ikS.e (Given ,h=5.672rc1U uICs umIs] 2.2-4
(b) Show that P1aneks low reduces to wien's law for shorter wavelength and Rayleigh-Jeans law for longer wavelengths. 3