Solved question paper for EME Dec-2005 (B-TECH 1st-2nd)
Solved Question Paper
Elements of mechanical engineering Dec-2005
PTU • B-TECH • Mechanical Engineering • 1st-2nd • Dec-2005
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-
State the Zeroth law of Thermodynamics.Short Answer Dec-2005 • PTU B-TECH
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May 2019 State Zeroth Law of Thermodynamics.
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Dec 2018 Define zeroth law of thermodynamics.
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May 2017 State and prove the Zeroth’s law of thermodynamics.
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Dec 2017 State the third law of thermodynamics.
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May 2016 Give the Kelvin-Plank statement of the second law.
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Dec 2016 State the Clausius statement of second law of thermodynamics.
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May 2015 State and explain the second law of thermodynamics.
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May 2015 State and prove the Zeroth’s law of thermodynamics.
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Dec 2008 Define third law of thermodynamics.
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Discuss whether (Pdv + Vdp) represent the system properties or not?Short Answer Dec-2005 • PTU B-TECH
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How enthalpy is related to the internal energy?Short Answer Dec-2005 • PTU B-TECH
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May 2011 What is the difference between total energy and enthalpy? Express both terms in detail.
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May 2011 What is the fundamental and basic difference between the terms enthalpy and total energy associated with the mass of a thermodynamic medium?
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May 2011 How enthalpy differs from the term heat transfer? Explain the difference between the two in detail.
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May 2010 Define enthalpy of the system. How is it related to internal energy?
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State the principle of entropy, draw T-S diagram for it.Long Answer Dec-2005 • PTU B-TECH
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A close system contains air at 1 bar, 190 K and occupies 0.02 m^3 of volume. This system is heated at constant volume till pressure become 4 bar. Draw P-V and T-S diagram only for the problem.Short Answer Dec-2005 • PTU B-TECH
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Draw P-V and T-S diagram for an engine operated by Dual cycle.Short Answer Dec-2005 • PTU B-TECH
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May 2013 Draw P-V and T-S plot for dual cycle.
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May 2010 Draw P-V and T-S diagrams for Brayton cycle.
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State the condition of reversibility of lifting machine.Short Answer Dec-2005 • PTU B-TECH
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Draw a stress-strain curve for a mild steel specimen.Short Answer Dec-2005 • PTU B-TECH
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May 2015 Draw and explain the stress-strain diagram for mild steel? Also describe how it is different from brittle materials.
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May 2011 Sketch stress-strain curves for ductile and brittle materials and show the salient points on it.
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Dec 2010 Sketch a Stress-Strain for ductile and brittle materials and show the salient point on it.
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May 2007 Draw stress strain curve for a typical brittle material.
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What is fatigue, define?Short Answer Dec-2005 • PTU B-TECH
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Which of the following material has the maximum ductility?MCQ Dec-2005 • PTU B-TECH
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State the condition for a process to be reversible.Short Answer Dec-2005 • PTU B-TECH
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Dec 2018 State the conditions for a process to be reversible.
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Dec 2012 State the conditions for a process to be reversible.
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Dec 2012 Explain the term reversibility as applied to a thermodynamic process.
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Dec 2009 What is reversible process? Also write conditions for reversibility.
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Classify the thermodynamic system and explain them with the help of simple diagrams.Long Answer Dec-2005 • PTU B-TECH
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A non flow reversible process occurs for which pressure and volume are correlated by the expression P=(V^2 + 6V), where P is in bar and V is m^3. What amount of work will be done when volume changes from 2 to 4 m^3?Long Answer Dec-2005 • PTU B-TECH
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May 2010 A non-flow reversible process occurs for which pressure and volume are correlated by the expression P = (V + 5/V), where P is in bar and V is in m3. What amount of work will be done when volume changes from 3 to 6 m3?
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Explain the corollaries of first law.Long Answer Dec-2005 • PTU B-TECH
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A close system having a mass of 50 Kg has an initial velocity of 10 m/s. Subsequently its velocity increases to 30 m/s and its elevation also rises by 40 m. During this process the system receives 30000 J of heat and 4500 J of work. If the system delivers 0.002 KWh of electrical energy, determine the change in internal energy of the system.Long Answer Dec-2005 • PTU B-TECH
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Differentiate between different polytropic process, draw common P-V diagram showing expression follow the law PV^n=C for n=0, n=1, n=n.Long Answer Dec-2005 • PTU B-TECH
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3 Kg of air kept at an absolute pressure of 100 Kpa and temperature of 300 K is compressed polytropically until the pressure and temperature becomes 1500 KPa and 500 K respectively. Evaluate the polytropic exponent, the final volume and the work of compression. Take gas constant, R=287 J/Kg K.Long Answer Dec-2005 • PTU B-TECH
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Explain revised heat engine Carnot cycle with the help of P-V diagram.Long Answer Dec-2005 • PTU B-TECH
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Three real heat engines have the same thermal efficiency and are connected in series. The first engine absorbs 2400 KJ of heat from a thermal reservoir at 1250 K and the third engine rejects its waste of 300 KJ to a sink at 150 K, determine the work output from each engine.Long Answer Dec-2005 • PTU B-TECH
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Explain the working principle of an air standard cycle with the help of P-V and T-S diagram.Long Answer Dec-2005 • PTU B-TECH
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A four stroke engine working on diesel cycle has a piston diameter 25 cm, stroke of 40 cm and clearance volume of 1200 cc. The fuel injection takes place for 5% of stroke. If the induction pressure corresponding to 1 bar and engine turns 5 rev/s, find the air standard efficiency of the engine and power developed.Long Answer Dec-2005 • PTU B-TECH
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Define input, output and efficiency of a simple lofting machine.Short Answer Dec-2005 • PTU B-TECH
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A simple lifting machine raised a load of 360 N through a distance of 200 mm. The effort a force of 60 N is moved 1.8 m during the process. Calculate velocity ratio, mechanical advantage and efficiency of the machine.Long Answer Dec-2005 • PTU B-TECH
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Torsion and bendingVery Short Answer Dec-2005 • PTU B-TECH
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Stress and strainVery Short Answer Dec-2005 • PTU B-TECH
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Sudden and impact loadVery Short Answer Dec-2005 • PTU B-TECH
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Modulus of rigidity and Bulk modulus.Very Short Answer Dec-2005 • PTU B-TECH
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What is creep? Explain the different stages of creep with the help of common diagram.Long Answer Dec-2005 • PTU B-TECH
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Differentiate between torsion and bending.Short Answer Dec-2005 • PTU B-TECH
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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.
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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.