(SEM-III) THEORY EXAMINATION 2019-20 THERMODYNAMICS

This document is the B.Tech Semester–III Theory Examination 2019–20 question paper for Thermodynamics (Sub Code: KME301) under Dr. A.P.J. Abdul Kalam Technical University (AKTU).
The uploaded paper contains three pages, clearly divided into SECTION A, SECTION B, and SECTION C.
The exam duration is 3 hours, and the total marks are 100.

The paper evaluates a student’s understanding of thermodynamic laws, Carnot cycle, P–T diagrams, irreversibility, phase equilibrium, energy equations, Rankine cycle, steam turbines, Joule–Kelvin effect, Clapeyron equation, heat interactions, entropy, and gas/vapour processes.

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

(Page 1 of the uploaded file)

Section A contains ten 2-mark questions, testing fundamental concepts of thermodynamics.

Topics include:

Critical point and triple point                                    First law limitations

Carnot theorem                                                          Third law of thermodynamics

Difference between Helmholtz & Gibbs functions    Meaning of 1 ton of refrigeration

Causes of irreversibility                                              P–T diagram of a pure substance

Effect of evaporator pressure and superheating on C.O.P.

Definition of inversion curve

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

(Page 1 bottom)

Students must choose any three of the long questions.

Topics include:

Steady flow energy equation (SFEE) for heat exchanger, nozzle, pump, turbine & boiler

P–V diagram based work/heat interactions

Application of First law to steady-flow systems

Steam properties, enthalpy relations

Basic thermodynamic processes & equations

Each question requires detailed derivation, explanation, or formulation.

SECTION C — Numerical & Advanced Questions (Q3–Q6)

(Pages 2 & 3)

Section C has four major questions (Q3, Q4, Q5, Q6).
Each contains two alternatives (a or b), and students must attempt one from each.

Q3 — Thermodynamic Cycle / Steady Flow Turbine

(Page 2)

(a) Three-process thermodynamic cycle with:

Compression                 Heat transfer                      Expansion
Given U₁, U₂, U₃ and W-values → Find Q₁₂ & Q₃₁.

(b) Steam turbine problem:

Inlet: 1.2 MPa, 188°C, enthalpy 2785 kJ/kg              Exit: 20 kPa, enthalpy 2512 kJ/kg

Given velocities & mass flow → Find power output.

Q4 — Carnot Cycle / Entropy Change

(Page 2)

(a) Carnot cycle with steam heated from 350°C → saturation at 27°C.
Calculate heat supplied & cycle work.

(b) Entropy change of 1 kg water on heating.

Q5 — Clapeyron Equation / Heat Rejection

(Page 3)

(a) Explain Clapeyron equation + Joule–Kelvin effect with inversion curve.
(b) Reversible engine between 525 K and 875 K, heat rejection at 290 K — Find:

Total heat abstracted

Availability

Loss of available work

Q6 — Rankine Cycle / Psychrometric Concepts

(Page 3)

(a) Steam turbine working on Rankine cycle with dry saturated steam at 25 bar, exhaust at 0.2 bar → Determine:

Quality at end of expansion                         Turbine work

Pump work                                                   Rankine efficiency

Heat flow to condenser                                Mass flow = 10 kg/s

(b) Define & explain:

Dry bulb temperature                                   Wet bulb temperature

Dew point temperature                                Relative humidity

Specific humidity                                          These cover psychrometry and steam cycle concepts.

OVERALL SUMMARY OF THE DOCUMENT

The Thermodynamics (KME301) exam paper thoroughly evaluates:

Fundamental Concepts

First, second, and third laws                                Carnot theorem

Irreversibility, availability & work potential         Thermodynamic properties: U, H, S, G, F

Applied Thermodynamics

P–T & P–V diagrams                                            Pure substance behavior

Phase rule, inversion curves                                Clapeyron & Joule–Kelvin relations

Systems & Cycles

Steady-flow devices (turbine, pump, nozzle, boiler)        Heat interactions and work transfer

Carnot and Rankine cycles                                               Refrigeration performance (COP)

Numericals

Power output from turbine                                  Heat interaction in cycles

Entropy change                                                    Psychrometric property calculations

The uploaded paper spans 3 pages, contains numerical problems, theoretical explanations, and cycle diagrams mentioned in text.