Solved question paper for EME May-2019 (B-TECH 1st-2nd)
Solved Question Paper
Elements of mechanical engineering May-2019
PTU • B-TECH • Mechanical Engineering • 1st-2nd • May-2019
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-
Distinguish between Intensive and Extensive properties.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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Distinguish between quasi static process and actual process.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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Dec 2023
Distinguish between quasi static process and actual process.
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State Zeroth Law of Thermodynamics.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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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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Dec 2005 State the Zeroth law of Thermodynamics.
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Distinguish between internal energy and enthalpy.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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May 2018 Differentiate between temperature, heat and internal energy.
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Dec 2016 Explain the difference between temperature, heat and internal energy.
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Dec 2014 Differentiate between temperature, heat and internal energy.
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Dec 2012 Differentiate between temperature, heat and internal energy.
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May 2010 Differentiate between temperature, heat and internal energy.
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What are positive and negative work interactions?Very Short Answer 2 Marks May-2019 • PTU B-TECH
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What is an air-standard efficiency?Very Short Answer 2 Marks May-2019 • PTU B-TECH
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May 2020 What is air standard efficiency?
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Dec 2020 What is Air Standard Efficiency?
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Dec 2019 Define air standard efficiency.
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May 2009 What is air standard efficiency?
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Explain Poission's ratio.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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Dec 2014 Define possion’s ratio?
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Define weldability.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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May 2020 Discuss the property of weldability.
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Dec 2020 Discuss the property of weldability.
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May 2017 Define Weldability.
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Enumerate the criteria for selection of materials for engineering applications.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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Dec 2023 List the major factors affecting the selection of materials.
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May 2012 List the major factors affecting the selection of materials.
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Define polar moment of inertia.Very Short Answer 2 Marks May-2019 • PTU B-TECH
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Dec 2017 Define moment of inertia.
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May 2015 Define Moment of Inertia.
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When a system is taken from ‘a’ to ‘b’ along the path ‘acb’, 400 kJ of heat flows into the system and the system does 100 kJ of work. How much heat flows into the system along the path ‘adb’ if the work done is 50 kJ?Short Answer May-2019 • PTU B-TECH
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If the system is brought from state ‘b’ to state ‘a’ along the curved path ‘ba’ and if the work done on the system is 100 kJ, find out the heat transfer of the system. Does it absorb or liberate heat?Short Answer May-2019 • PTU B-TECH
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If the value of internal energy Ua = 0 and Ud = 200 kJ find the heat transfer in the process ad and db.Short Answer May-2019 • PTU B-TECH
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Derive steady flow energy equation for a single stream of fluid entering and leaving the control volume.Long Answer 8 Marks May-2019 • PTU B-TECH
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Dec 2023 Derive steady flow energy equation for a single stream of fluid entering and leaving the control volume.
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May 2016 Give the differential form of the steady flow energy equation.
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Dec 2016 State the basic assumptions of steady flow energy equation.
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Dec 2009 Explain and derive steady flow energy equation.
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May 2007 State and write the steady flow energy equation.
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One mol of an ideal gas at 0.5 MPa and 300 K is heated at constant pressure till the volume is doubled and then it is allowed to expand reversibly and adiabatically till the temperature is reduced to 300 K. Calculate heat and work transfers. If it is desired to restore the system from final state to its initial state by a reversible isothermal process what amount of work is required to be done on the system?Long Answer 8 Marks May-2019 • PTU B-TECH
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Two reversible heat engines are arranged in series between temperatures 500°C and 0°C. The heat input from heat source at 500 °C is 300 kJ. The work output of the first engine is twice of the second engine. Determine T2, η1, η2 and Q3.Long Answer 8 Marks May-2019 • PTU B-TECH
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May 2009 Two reversible heat engines E1 and E2 are arranged in series between a hot reservoir at temperature T1 of 600 K and a cold reservoir at temperature T3 of 300 K. Engine E1 receives 500 kJ of heat from reservoir at T1. Presuming that both engines have equal thermal efficiency determine the temperature at which heat is rejected by E1 and is received by engine E2.
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May 2009 Two reversible heat engines E1 and E2 are arranged in series between a hot reservoir at temperature T1 of 600 K and a cold reservoir at temperature T3 of 300 K. Engine E1 receives 500 kJ of heat from reservoir at T1. Presuming that both engines have equal thermal efficiency determine the thermal efficiency of each engine.
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May 2009 Two reversible heat engines E1 and E2 are arranged in series between a hot reservoir at temperature T1 of 600 K and a cold reservoir at temperature T3 of 300 K. Engine E1 receives 500 kJ of heat from reservoir at T1. Presuming that both engines have equal thermal efficiency determine the work done by engine E1 and E2.
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May 2009 Two reversible heat engines E1 and E2 are arranged in series between a hot reservoir at temperature T1 of 600 K and a cold reservoir at temperature T3 of 300 K. Engine E1 receives 500 kJ of heat from reservoir at T1. Presuming that both engines have equal thermal efficiency determine the heat rejected by engine E2 to cold reservoir.
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An engine working on the Otto cycle is supplied with air at 1.1 MPa, 35°C. The compression ratio is 8. Heat supplied is 2100 kJ/kg. Calculate the maximum pressure and temperature of the cycle, the cycle efficiency, and the mean effective pressure. (For air, cp = 1.005, cv = 0.718, and R = 0.287 kJ/kg K).Long Answer 8 Marks May-2019 • PTU B-TECH
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Dec 2023 An engine working on the Otto cycle is supplied with air at 1.1 MPa, 35°C. The compression ratio is 8. Heat supplied is 2100 kJ/kg. Calculate the maximum pressure and temperature of the cycle, the cycle efficiency and the mean effective pressure.
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Explain classification of Engineering materials. Explain characteristics of key engineering materials used in manufacturing.Long Answer 8 Marks May-2019 • PTU B-TECH
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Dec 2023 Explain classification of Engineering materials and characteristics of key engineering materials used in manufacturing. https://www.pustudy.com
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Prove the parallel axis theorem in the determination of moment of inertia of areas with the help of a neat sketch.Long Answer 8 Marks May-2019 • PTU B-TECH
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Dec 2011 Prove the parallel axis theorem in the determination of moment of inertia of areas with the help of a neat sketch.
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Find the centre of gravity of I section shown in the figure.Long Answer 8 Marks May-2019 • PTU B-TECH
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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.