(SEM III) THEORY EXAMINATION 2020-21 THERMODYNAMICS

This document is the B.Tech Semester III (2020–21) Theory Examination question paper for the subject THERMODYNAMICS (KME301) under Dr. A.P.J. Abdul Kalam Technical University (AKTU).
The exam carries 100 marks, the duration is 3 hours, and the paper is divided into three main sections — SECTION A, SECTION B, and SECTION C — exactly as shown across the two uploaded pages.

The paper evaluates a student’s understanding of fundamental thermodynamic laws, properties of pure substances, heat engines, compressors, refrigeration cycles, Rankine cycle, entropy, and energy availability.

SECTION A — Short Answer Questions (10 × 2 = 20 Marks)

This section appears on Page 1 and contains 10 brief questions, each carrying 2 marks.
These questions cover essential thermodynamic basics:

Difference between macroscopic and microscopic viewpoints

Reversible process and its conditions

Third law of thermodynamics

Principle of entropy increase

Meaning of effectiveness and irreversibility

Adiabatic vs isothermal compressibility

Sensible heat and latent heat of vaporization

Dryness fraction calculation of wet steam

Properties of refrigerant

Bell Coleman cycle definition

These short questions test conceptual clarity and quick recall of fundamental principles.

SECTION B — Long Answer Questions (Attempt Any 3 × 10 = 30 Marks)

Section B begins on Page 1.
There are five descriptive questions, from which students must attempt any three.

Topics include:

Polytropic gas expansion with given p–v1.2=Cp–v^{1.2} = Cp–v1.2=C relationship and heat transfer calculation

Derivation of thermal efficiency of Carnot engine

Loss of available energy during heat transfer in a steam generator

Rankine cycle efficiency for steam plant operating between 260°C and 95°C

COP of absorption refrigeration system given operating temperatures

These questions require formulas, thermodynamic relationships, and numerical calculations.

SECTION C — Advanced / Applied Thermodynamics (Q3–Q7, 10 Marks Each)

Section C spans Page 1 and Page 2, containing five groups (Q3 to Q7).
For each group, students must attempt any one part (a or b).

Q3 — Compressor–Turbine System OR Air-Standard Cycle

Turbine exhaust temperature from compressor–heater–turbine system
OR

Complete thermodynamic analysis of an air cycle (adiabatic compression, constant-pressure heating, constant-volume cooling)

Q4 — Heat Engine + Heat Pump OR Entropy Change

Ratio of heat transfers using heat engine & heat pump combination
OR

Entropy change during adiabatic mixing of water at two different temperatures

Q5 — Availability & Irreversibility OR Clausius–Clapeyron Equation

Availability transfer rate and irreversibility in an adiabatic compressor
OR

Derivation of Clausius–Clapeyron equation

Q6 — Steam Power Cycle OR Steam Power Plant

Rankine cycle with ideal and real processes (turbine & pump efficiencies)
OR

Components and working of steam power plant with schematic

Q7 — Vapour Compression Refrigeration Cycle

All processes of VCR cycle with p–v and T–s diagrams
OR

Calculations for standard VCR cycle using refrigerant F-12:

Refrigerant flow rate

Power consumption

COP of the cycle

This section evaluates students on cycle analysis, energy interactions, efficiency, entropy, and refrigeration/steam system performance.

OVERALL SUMMARY OF THE DOCUMENT

The Thermodynamics (KME301) exam paper thoroughly assesses the following core areas:

Basic thermodynamic laws and concepts

Reversible & irreversible processes

Entropy, availability, irreversibility

Heat engines, Carnot cycle

Steam power cycles (Rankine cycle)

Refrigeration cycles (Bell Coleman & vapour compression)

Air-standard cycles

Compressors & turbines

Properties of pure substances (dryness fraction, latent heat)

Real-world thermodynamic systems and energy calculations

The structure of the paper is balanced:

Section A → Quick conceptual recall

Section B → Numerical + derivation-focused problems

Section C → Full thermodynamic cycle analysis and applied systems

This document provides a complete, standard AKTU-style thermodynamics assessment.