Download GTU B.Tech 2020 Winter 4th Sem 2143406 Thermo Dynamics And Thermal Eng. Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Winter 4th Sem 2143406 Thermo Dynamics And Thermal Eng. Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE- SEMESTER?IV (NEW) EXAMINATION ? WINTER 2020
Subject Code:2143406 Date:09/02/2021
Subject Name:Thermo Dynamics and Thermal Eng.
Time:02:30 PM TO 04:30 PM Total Marks:56
Instructions:
1. Attempt any FOUR questions out of EIGHT questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.
Q.1 (a) Define:
03
(1) Thermal Equilibrium
(2)Mechanical Equilibrium
(3)Chemical Equilibrium

(b) Differentiate Heat & Work
04

(c) Explain phase change for Pure Substance
07


Q.2 (a) Write down a Application of First Law of Thermodynamics
03

(b) Differentiate Otto Cycle & Diesel Cycle
04

(c) Explain the different variables affecting on an efficiency of Rankine cycle
07
Q.3 (a) Define Available and Unavailable Energy
03

(b) Derive the Maxwell relations and explain their importance in thermodynamics. 04

(c) Derive Clausius-Claperyon Equation with p-T Diagram
07




Q.4 (a) Differentiate between availability function and Gibb's energy function.
03

(b) Write a Joule-Thomson Co-efficient
04

(c) Derive first form of entropy equation;
07
= + (
)
Q.5 (a) Define Partial Pressure and Mole Fraction
03

(b) The volume of a high altitude chamber is 40 m3. It is put into operation by 04
reducing pressure from 1 bar to 0.4 bar and temperature from 25?C to 5?C
How many kg of air must be removed from the chamber during the process.
Express this mass as a volume measured at 1 bar and 25?C.
Take R = 287 J/kg K for air.

(c) Show that specific heats of a gas mixture;
07
- =



Q.6 (a) Write a short note on Adiabatic Mixing of Perfect Gases
03

(b) Explain briefly Dalton's law and Gibbs-Dalton law.
04

(c) 8 Kg of air at 650 K and 5.5 bar pressure is enclosed in a closed system. If the 07
atmospheric temperature and pressure are 300 K and 1 bar respectively,
determine:
The availability if the system goes through the ideal work producing process.
The availability and effectiveness if the air is cooled at constant pressure to
atmospheric temperature without bringing it to complete dead state. Take =
0.718 kJ/Kg K; = 1.005 kJ/Kg K
1

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Q.7 (a) Explain Mode of Heat Transfer.
03

(b) Derive the mathematical expression for the Critical insulation thickness.
04

(c) The inner surface of a plane brick wall is at 60?C and the outer surface is at 07
35?C. Calculate the rate of heat transfer per m2 of surface area of the wall,
which is 220 mm thick. The thermal conductivity of the brick is 0.51 W/m?C.



Q.8 (a) Write a short note on Radiation
03
(b) Define Absorptivity, Reflectivity, Transmissivity Emissivity
04
(c) Derive the condition for minimum resistance and consequently maximum heat 07
flow rate
=
Where, = Heat transfer coefficient at the outer surface of the insulation
= Thermal conductivity of insulating material


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