Solved question paper for EME Dec-2023 (B-TECH 1st-2nd)
Solved Question Paper
Elements of mechanical engineering Dec-2023
PTU • B-TECH • Civil Engineering • 1st-2nd • Dec-2023
elements of mechanical engineering previous year question papers on BRpaper are organized for students of Punjab Technical University’s Bachelor of Technology program, 1st-2nd semester. This section makes it easier to browse subject-wise old question papers for elements of mechanical engineering, so students can review how questions are typically framed in past exams and get a sense of the exam pattern. Many students search for elements of mechanical engineering question bank while preparing for exams, and this page is built to support exactly that kind of subject-wise browsing and revision. BRpaper is not the official website of Punjab Technical University or any institution, and it does not publish official notices or academic updates.
PART-A
1. Basic Concepts of Thermodynamics (08)
Definition of thermodynamic: Need to study thermodynamics; Application areas of thermodynamic; Difference between Microscopic (or, Statistical) thermodynamics and Macroscopic(or, Classical) thermodynamics; Brief concept of continuum; Thermodynamic System : definition, types (Open, Closed and Isolated) and their examples; Thermodynamic System Boundary : definition, types and their examples; Surroundings; Control(fixed) mass and Control Volume concept and their example ; Thermodynamic State; Thermodynamic Property: definition, types citing their examples; condition for any quantity to be a property; State postulate; Thermodynamic equilibrium (which includes Thermal, Mechanical and Chemical equilibrium etc.); Thermodynamic path; Thermodynamic process: definition, concept of reversible process, quasi-static (or, quasi-equilibrium) process, irreversible process, conditions for reversibility and how these are met with, non-flow processes and flow processes, method of representation of reversible and irreversible process on property diagrams; Cyclic process; Thermodynamic Cycle: definition and its concept; Energy and its forms (microscopic and macroscopic); Physical insight to internal energy; Energy transfer across system boundary i.e. transient energies (heat and work); Difference between heat and work; Sign conventions for heat and work interactions; heat and work as path functions; Equality of Temperature and Zeroth law of Thermodynamics.
2. First Law of Thermodynamics and its applications (12)
Definition, essence and corollaries or consequences of first law of Thermodynamics; Expressions for First law of Thermodynamics for a control mass undergoing a Cycle and for process (i.e., a change in state of a control mass) ; Concept of Enthalpy and total energy and differentiation between the two - a thermodynamic property; Compressible and incompressible substances, Specific heats, Difference between Internal Energy and Enthalpy of compressible and incompressible substances; Representation of first law of thermodynamics as rate equation; Analysis of non-flow/ flow process for a control mass undergoing constant volume, constant pressure, constant temperature, adiabatic and polytropic processes; Free Expansion Process and its examples, its representation on Property diagram; Review of concepts of control volume; Expressions of first law of thermodynamics for a control volume (i.e. open system) ; Steady State Steady Flow process and its examples; First law analysis of Steady State Flow process e.g. isochoric, isobaric, isothermal, isentropic and polytropic process; Throttling process and its applications; Flow energy or inertial energy of flowing fluids or, Energy transport by mass; Application of Steady State Flow Energy Equation to various engineering devices.
3. Second Law of Thermodynamics (16)
Limitations of first law of thermodynamics; and how 2nd law is fully able to explain away and thus overcome those shortcomings of Ist law; Thermal Reservoirs, source and sink (Low temperature and high temperatures); Heat Engine, Heat Pump and Refrigerator: definitions, working, efficiency/performance and their real life examples. Justification as to why the actual efficiency of Heat Pump and Refrigerator shall also be ≤ 100% though on the face of it seems to be more than 100%; Various statements of Second Law of Thermodynamics and their equivalence; Philosophy of Carnot cycle and its consequences viz. how each of the individual four processes constituting the cycle contribute in optimizing the output and efficiency of the cycle; Carnot Engine, Carnot Refrigerator and Carnot Heat Pump: definitions, working, efficiency/performance and Limitations of the cycle; Carnot theorem for heat engines, refrigerators and heat pumps; derivation of Carnot efficiency/COP (which seems to be more than 100%); Thermodynamic Temperature Scale; Clausius theorem and Inequality; Philosophy and concept of entropy; Entropy changes during various processes; Temperature - Entropy Chart and representation of various processes on it; Principle of Increase of Entropy; Applications of Entropy Principle; Quality of Energy viz. high and low grade energies; Degradation of Energy; Third Law of Thermodynamics.
PART-B
4. Gas Power Cycles (12)
Introduction; Concept and philosophy of Air Standard Cycle alongwith associated assumptions and advantages; Air Standard Efficiency; Nomenclature of reciprocating piston-cylinder arrangement with basic definitions such as swept volume, clearance volume, compression ratio, mean effective pressure etc; Otto Cycle (or constant volume heat addition cycle), Diesel cycle (or constant pressure heat addition cycle) and Dual cycle (Mixed or Composite or Limited Pressure cycle) with their representation on P-V and T-S charts, their Air-standard (thermal) Efficiencies; Brayton Cycle, Comparison of Otto, Diesel and Dual cycle under some defined similar parametric conditions; Introduction to heat engines; Merits of I.C. Engines and their important applications, Classification and constructional features of I.C. Engines; working of two stroke and four stroke Petrol and Diesel engines and their comparison.
5. Engineering Materials (05)
Materials and Civilization, Materials and Engineering, Classification of Engineering Materials, Mechanical Properties of Materials: elasticity, plasticity, strength, ductility, brittleness, melleability, toughness, resilience, hardness, machinability, formability, weldability. Properties, Composition, and Industrial Applications of materials: metals (ferrous- cast iron, tool steels, stainless steels and non ferrous- Aluminum, brass, bronze ), polymers (natural and synthetic , thermoplastic and thermosetting), ceramics (glass, optical fibre glass, cements), composites ( fibre reinforced, metal matrix), smart materials (piezoelectric, shape memory, thermochromic, photochromic, magnetorheological), Conductors, Semiconductors and insulators, Organic and Inorganic materials. Selection of materials for engineering applications.
6. Centroid, Centre of Gravity and Moment of Inertia: (08)
Difference between centre of gravity and centroid. Determination of position of centroid of plane geometric figures of I, U, H, L, T, C, Circular and Triangular Sections. Centroid of Composite Areas. Determination of position of Centre of Gravity (CG) of regular solids viz. Right Circular Cone, Solid Hemisphere, thin Hollow Hemisphere. Area moment of inertia & mass moment of inertia, Polar moment of inertia, Parallel axes Theorem (or transfer formula), Perpendicular axes Theorem, Radius of gyration, determination of area Moment of Inertia of I, U, H, L, T, C, Circular and Triangular Sections along various axes. Mass moment of Inertia of Circular Ring, Disc, Cylinder, Sphere and Cone about their axis of symmetry and other axes.
Solved Questions
Solved-
Define "intensive" and "extensive" thermodynamic properties.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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Distinguish between open and closed thermodynamic system.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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What do you mean by non-flow processes? Give example.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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May 2009 What are non-flow processes? Give suitable examples.
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Discuss the concept of control volume.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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Distinguish between heat pump and refrigerator.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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May 2015 Differentiate between heat engine, heat pump and refrigerator.
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May 2012 Differentiate between a heat pump and a refrigerator.
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Discuss the concept of "regeneration" in gas power cycles.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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List some important applications of I.C. Engines.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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Discuss the concept of "hardness" as a material property.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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Dec 2016 What is meant by hardness of a material?
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Name some common examples of non-ferrous metals.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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Define centroid with a suitable example.Very Short Answer 2 Marks Dec-2023 • PTU B-TECH
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May 2017 Define Centroid.
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a) Explain the following terms : i) State, ii) Process, and iii) CycleVery Short Answer Dec-2023 • PTU B-TECH
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Dec 2017 Explain the terms state, path, process and cycle.
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May 2012 Define the terms state, property, process and cycle.
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b) The properties of a closed system change following the relation between pressure and volume as PV = 3.0 where P is in bar, V is in m^3. Calculate the work done when the pressure increases from 1.5 bar to 7.5 bar.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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0.44 kg of air at 180°C expands adiabatically to three times its original volume and during the process, there is a fall in temperature to 15°C. The work done during the process is 52.5 kJ. Calculate specific heats at constant pressure and volume.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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a) State Clausius and Kelvin-Planck statements of second law of thermodynamics and prove their equivalence.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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May 2017 State and explain the Kelvin Planck and Claussis statement of second law of thermodynamics.
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Dec 2017 State second law of thermodynamics. Prove the equivalence of Kelvin-Planck statement and Clausius statement of second law of thermodynamics.
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May 2015 State Kelvin-Planck and Claussius statements of second law of thermodynamics? Also show equivalence between them.
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Dec 2014 State Kelvin-Planck and Clausius statements of second low of thermodynamics? Also show equivalence between them.
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May 2010 State Kelvin-Planck and Clausius statements of second law of thermodynamics. Explain the equivalence of Kelvin-Planck and Clausius statements.
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May 2009 Discuss equivalence of various statements of the second law of thermodynamics.
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Dec 2009 Write various statements of second law of thermodynamics and also show their equivalence.
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b) State and prove Clausius inequality.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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May 2016 Explain the concept of Clausius Inequality.
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Dec 2016 What is Clausius inequality?
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May 2012 State and prove Clausius inequality.
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Dec 2011 State and prove Clausius inequality.
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a) Define entropy and prove that it is property of a system.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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May 2014 Define the term entropy. Show that entropy is a property of the system.
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May 2012 Define the term entropy. Show that entropy is a property of the system.
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b) State and explain principle of increase of entropy.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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Draw Otto cycle and derive its air standard efficiency and mean effective pressure.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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Dec 2018 Derive an expression for the air standard thermal efficiency of Otto cycle.
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May 2017 Derive the expression for air standard efficiency for Otto cycle. Also draw its PV and T-S diagram.
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Dec 2016 Derive an expression for efficiency and mean effective pressure of Otto cycle.
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Dec 2010 Derive an expression for the air standard efficiency and mean effective pressure of an Otto cycle. State the assumptions made.
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May 2007 Derive the expression for the air standard efficiency for otto cycle.
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a) Explain the following properties of Engineering materials : i) Strength, ii) Brittleness, iii) Toughness, and iv) Weldability.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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b) What do you mean by composite materials? Distinguish between fibre reinforced and metal matrix composites.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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a) Find the moment of inertial of a semi circle about its diametrical axis.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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Dec 2016 Find the moment of inertia of a circle about its diametrical axis.
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May 2012 Find the moment of inertia of a semi circle about its diametrical axis.
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b) Find the centroid of a quarter of a circle.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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Dec 2016 Find the centroid of a quarter of a circle.
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May 2012 Find the centroid of a quarter of a circle.
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Explain the construction and working of four stroke petrol engine.Long Answer 8 Marks Dec-2023 • PTU B-TECH
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Dec 2019 Explain the working of two stroke petrol engine giving neat sketch.
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Dec 2018 Explain the working of a two-stroke petrol engine with the help of neat sketches. What are the demerits of two-stroke engines?
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May 2016 Write short notes on working of two stroke petrol engine.
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May 2013 Discuss briefly the working of a 4 Stroke Petrol engine.
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May 2012 Describe the working principle of a two stroke petrol engine with a neat diagram.
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Dec 2011 Explain the working of two stroke C.I. engine with the help of neat sketches.
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May 2007 Explain the working of two stroke IC engine with neat sketches.
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Dec 2007 Explain the working of four stroke IC engine with neat sketches.
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Answers about this subject, solved papers, and preparation.
01 Where can I find elements of mechanical engineering previous year question papers for Bachelor of Technology, 1st-2nd semester?
This page lists elements of mechanical engineering question papers uploaded for Punjab Technical University Bachelor of Technology, 1st-2nd semester, organized for subject-wise browsing where available.
02 Are these official Punjab Technical University question papers?
BRpaper is not the official website of Punjab Technical University. These papers are shared for reference and revision purposes only and are not official university material.
03 How can previous year elements of mechanical engineering papers help in exam preparation?
Reviewing past papers can help you understand how questions are typically framed, notice commonly repeated topics, and get a sense of the exam pattern before your own exam.
04 What kind of topics does elements of mechanical engineering usually cover?
The question papers here relate to the official elements of mechanical engineering syllabus set by the university for this course and semester.
05 Does this page include a elements of mechanical engineering question bank or solved answers?
This page focuses on providing access to the previous year question papers themselves. A separate question bank or solved answers may not be available for every paper.
06 Can I find papers for other subjects in the same Bachelor of Technology?
Yes, BRpaper organizes papers by university, course, stream, and semester, so you can browse other subjects within the same Punjab Technical University Bachelor of Technology.