Solved question paper for EME May-2020 (B-TECH 1st-2nd)
Solved Question Paper
Elements of mechanical engineering May-2020
PTU • B-TECH • Information Technology • 1st-2nd • May-2020
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 a thermodynamics system.Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 Define a Thermodynamics System.
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May 2015 What is Thermodynamics?
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Dec 2014 What is thermodynamic system?
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May 2008 Explain thermodynamic system.
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Explain briefly the zeroth law of thermodynamics.Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2023
Name and state the property introduced by the first law of thermodynamics.
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Dec 2023 What is the essence of first law of thermodynamics? Write down expression for the first law applied to
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Dec 2020 Explain briefly zeroth law of thermodynamics.
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Dec 2020 Explain the first law of thermodynamics with respect to close systems.
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May 2016 Name and state the property introduced by the first law of thermodynamics.
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Dec 2016 What is first law of thermodynamics?
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May 2015 Define and explain the Zeroth law of thermodynamics.
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May 2013 What is the essence of first law of thermodynamics? Write down expression for the first law applied to cycle.
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May 2013 What is the essence of first law of thermodynamics? Write down expression for the first law applied to process.
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Dec 2010 Define and explain the Zeroth law of thermodynamics. Why is it so called.
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Dec 2009 Define and explain Zeroth law of thermodynamics? Why it is so called?
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May 2008 What is zeroth law of thermodynamics?
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What is triple point?Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 What is Triple Point?
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Define internal energy.Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 Define Internal Energy.
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May 2017 Define internal energy.
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May 2016 Define internal energy.
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Dec 2014 Define internal energy?
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May 2008 Define internal energy.
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What do you mean by PMM of first kind?Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 What do you mean by PMM of first kind?
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Dec 2020 What do you mean by PMM of the second kind?
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May 2010 What is PMM1?
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Explain the concept of available and unavailable energy.Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 Explain the concept of available and unavailable energy.
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May 2016 Define the terms available energy and unavailable energy.
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What is air standard efficiency?Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 What is Air Standard Efficiency?
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May 2019 What is an 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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Define the term true stress.Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 Define the term True Stress.
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Dec 2020 Define the term true stress.
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Under what conditions do the center of mass and center of gravity coincide?Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 Under what conditions do the center of mass and center of gravity coincide?
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What is the difference between thermoplastic and thermosetting materials?Short Answer 2 Marks May-2020 • PTU B-TECH
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Dec 2020 What is the difference between thermoplastic and thermosetting materials?
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May 2017 Differentiate between thermoplastics and thermosetting plastics.
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May 2012 Differentiate between thermoplastic and thermosetting plastic.
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To a closed system 150 kJ of work is supplied. If the initial volume is 0.6 m³ and the pressure of the system changes as p = 8 - 4V, where p is in bar and V is in m³, determine the final volume and pressure of the system.Long Answer 8 Marks May-2020 • PTU B-TECH
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Dec 2020 To a close system 150kJ of work is supplied. If the initial volume is 0.6 m3 and the pressure of the system changes as p = 8 - 4V, where p is in bar and V is in m3, determine the final volume and pressure of the system.
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May 2009 The pressure-volume correlation for a non-flow reversible process is given by p = (5 - 4V) bar, where V is in m3. If 150 kJ of work is supplied to the system, determine the final pressure and volume. Take initial volume = 0.6 m3.
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For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, find the pressure at the end of constant volume cooling.Long Answer May-2020 • PTU B-TECH
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May 2020 For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, determine the change in internal energy during the constant volume process.
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May 2020 For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, calculate the net work done and heat transferred during the cycle.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the pressure at the end of constant volume cooling.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the change in internal energy during constant volume process.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the net work done and heat transferred during the cycle. Assume Cp = 4.3 kJ/kg K and Cv = 10.2 kJ/kg K.
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For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, determine the change in internal energy during the constant volume process.Long Answer May-2020 • PTU B-TECH
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May 2020 For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, find the pressure at the end of constant volume cooling.
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May 2020 For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, calculate the net work done and heat transferred during the cycle.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the pressure at the end of constant volume cooling.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the change in internal energy during constant volume process.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the net work done and heat transferred during the cycle. Assume Cp = 4.3 kJ/kg K and Cv = 10.2 kJ/kg K.
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For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, calculate the net work done and heat transferred during the cycle.Long Answer May-2020 • PTU B-TECH
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May 2020 For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, find the pressure at the end of constant volume cooling.
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May 2020 For 0.1 m³ of an ideal gas at 300 K and 1 bar compressed adiabatically to 8 bar, then cooled at constant volume and further expanded isothermally to the initial condition, determine the change in internal energy during the constant volume process.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the pressure at the end of constant volume cooling.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the change in internal energy during constant volume process.
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Dec 2020 0.1 m3 of an ideal gas at 300K and 1 bar is compressed adiabatically to 8 bar. It is then cooled at constant volume and further expanded isothermally so as to reach the condition from where it started. Calculate the net work done and heat transferred during the cycle. Assume Cp = 4.3 kJ/kg K and Cv = 10.2 kJ/kg K.
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Write down the general energy equations for a steady flow system and simplify it for a centrifugal water pump.Long Answer May-2020 • PTU B-TECH
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Dec 2020 Write down the general energy equations for steady flow system and simplify when applied to a centrifugal water pump.
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Dec 2017 Apply steady flow energy equation to a centrifugal pump.
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Write down the general energy equations for a steady flow system and simplify it for a steam nozzle.Long Answer May-2020 • PTU B-TECH
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Dec 2020 Write down the general energy equations for steady flow system and simplify when applied to a steam nozzle.
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May 2012 Write down the general steady flow energy equation and deduce it for a nozzle, stating the assumptions taken.
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A closed system contains a pressure of 1 bar, temperature 300 K and volume 0.018 m³. It undergoes a thermodynamic cycle consisting of constant volume heat addition till pressure becomes 5 bar, constant pressure cooling, and isothermal heating to the initial state. Represent the cycle on T-S and p-V plots and evaluate the change in entropy for each process.Long Answer 8 Marks May-2020 • PTU B-TECH
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Dec 2020 A closed system contains at a pressure 1 bar, temperature 300 K and volume 0.018 m3. This system undergoes a thermodynamics cycle consisting of the following three processes in series: constant volume heat addition till pressure becomes 5 bar; constant pressure cooling; isothermal heating to initial state. Represent the cycle on T-S and p-V plots and evaluate the change in entropy for each process. Cp=0.718 kJ/kg K and R = 0.287 kJ/kg
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An engine of 250 mm bore and 375 mm stroke works on Otto cycle. The clearance volume is 0.00263 m³. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, determine the air standard efficiency of the cycle.Long Answer May-2020 • PTU B-TECH
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May 2020 An engine of 250 mm bore and 375 mm stroke works on Otto cycle. The clearance volume is 0.00263 m³. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, determine the mean effective pressure of the cycle, assuming ideal conditions.
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Dec 2020 An engine of 250 mm bore and 375 mm stroke works on otto cycle. The clearance volume is 0.00263 m3. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, find the air standard efficiency of the cycle.
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Dec 2020 An engine of 250 mm bore and 375 mm stroke works on otto cycle. The clearance volume is 0.00263 m3. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, find the mean effective pressure of the cycle, assume the ideal conditions.
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An engine of 250 mm bore and 375 mm stroke works on Otto cycle. The clearance volume is 0.00263 m³. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, determine the mean effective pressure of the cycle, assuming ideal conditions.Long Answer May-2020 • PTU B-TECH
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May 2020 An engine of 250 mm bore and 375 mm stroke works on Otto cycle. The clearance volume is 0.00263 m³. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, determine the air standard efficiency of the cycle.
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Dec 2020 An engine of 250 mm bore and 375 mm stroke works on otto cycle. The clearance volume is 0.00263 m3. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, find the air standard efficiency of the cycle.
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Dec 2020 An engine of 250 mm bore and 375 mm stroke works on otto cycle. The clearance volume is 0.00263 m3. The initial pressure and temperature are 1 bar and 50°C. If the maximum pressure is limited to 25 bar, find the mean effective pressure of the cycle, assume the ideal conditions.
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Discuss briefly the method employed for improvement of thermal efficiency of open cycle gas turbines.Long Answer 8 Marks May-2020 • PTU B-TECH
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Dec 2020 Discus briefly the method employed for improvement of thermal efficiency of open cycle gas turbines.
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Discuss the property of ductility.Short Answer May-2020 • PTU B-TECH
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Dec 2020 Discuss the property of ductility.
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Dec 2008 Define ductility.
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May 2007 Define ductility.
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Discuss the property of resilience.Short Answer May-2020 • PTU B-TECH
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Dec 2020 Discuss the property of resilience.
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Discuss the property of weldability.Short Answer May-2020 • PTU B-TECH
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Dec 2020 Discuss the property of weldability.
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May 2019 Define weldability.
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May 2017 Define Weldability.
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Discuss the property of plasticity.Short Answer May-2020 • PTU B-TECH
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Dec 2020 Discuss the property of plasticity.
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Determine the moment of inertia of a semicircular arc about its diameter and hence locate its centroid.Long Answer 8 Marks May-2020 • PTU B-TECH
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Dec 2020 Determine the moment of inertia of a semicircular arc about its diameter and hence locate its centroid.
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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.