(SEM-III) THEORY EXAMINATION 2017-18 THERMODYNAMICS

This document contains the complete B.Tech Semester III – Theory Examination 2017–18 question paper for Thermodynamics (RME-302). The paper spans three pages, carries 70 marks, and evaluates a student’s understanding of fundamental laws of thermodynamics, energy transfer, entropy, steady-flow devices, heat engines, refrigeration cycles, and real-gas behavior.

Section A – Short Conceptual Questions (14 Marks)

Section A includes seven 2-mark questions that test essential thermodynamic definitions and principles:

Meaning and discussion of a quasi-static process

Carnot theorem and ideal heat engine limitations

Concept of entropy

Definition of second-law efficiency

Joule–Thomson coefficient and its significance

Triple point and critical point of a substance

Definition of refrigeration effect

These questions ensure a strong foundation in classical thermodynamics.
 

Section B – Numerical & Analytical Problems (21 Marks)

Students must attempt any three out of five detailed questions involving derivations and numerical calculations:

Derivation of the Steady Flow Energy Equation (SFEE) and its application to heat exchangers, nozzles, turbines, pumps & boilers

A complex p–v process involving internal energy calculation, quasi-static work, heat transfer, and comparison between reversible and irreversible work

Two reversible heat engines in series → determining intermediate temperature, efficiencies, and heat rejection

Entropy change during cooling/heating of an iron cube dropped in water, and determining whether the process is reversible or irreversible

Coefficient of volume expansion, adiabatic & isothermal compressibility, and loss in available energy for gas receiving heat from a high-temperature reservoir

These questions test the student's depth in applying first-law and second-law concepts to real engineering systems.
 

Section C – Long, Advanced Thermodynamics Questions (35 Marks)

Each question contains two advanced subparts, and the student must attempt one from each group.

Q3 – Nozzles / Polytropic Processes

Exit velocity & mass flow rate of a nozzle using enthalpy drop

Area change based on specific volume variation
OR

Polytropic expansion in a flexible container with given internal-energy drop → compute work and heat transfer

Q4 – Mixing / Thermodynamic Laws

Adiabatic mixing of hot & cold water → entropy change
OR

Limitations of First Law, statements of Second Law, and proof that violating Kelvin–Planck statement violates the Clausius statement

Q5 – Availability / Real-Gas Equations

Maximum useful work available from a heat reservoir and loss in availability due to temperature drop
OR

Clapeyron equation, Joule–Kelvin effect, inversion curve & inversion temperature

Q6 – Rankine Cycle / Steady Flow Turbine

Full explanation of the Rankine cycle with P-V and T-S diagrams & calculation of changes in thermodynamic properties when water is heated to superheated steam
OR

Power output of a steam turbine using SFEE with elevation, enthalpy, velocity, and heat-loss data

Q7 – Refrigeration Cycles

Vapor Compression Refrigeration (VCR) cycle, T-S & P-H diagrams, flow diagram, COP & reversibility
OR

Bell–Coleman (Air Refrigeration) cycle → finding COP using polytropic relations

This section thoroughly examines higher-level thermodynamic reasoning and engineering application.
 

Summary

This Thermodynamics (RME-302) exam paper thoroughly evaluates:

First & Second Laws of Thermodynamics

Carnot cycle & ideal heat engines

Entropy & availability (exergy)

SFEE & steady-flow devices (turbines, nozzles, pumps, compressors)

Real gas behavior (Joule–Thomson effect, inversion temperature)

Heat engines & refrigeration cycles (VCR, Bell-Coleman)

Rankine cycle & steam power plant basics

Entropy generation & irreversibility

It is a complete academic resource for mechanical engineering students studying classical & applied thermodynamics.