Solved question paper for EME May-2013 (B-TECH 1st-2nd)
Solved Question Paper
Elements of mechanical engineering May-2013
PTU • B-TECH • Civil Engineering • 1st-2nd • May-2013
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-
Convert 0.5 bar of pressure into: (i) mm of Hg, (ii) m of water.Short Answer 2 Marks May-2013 • PTU B-TECH
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What is the concept of continuum? How will you define density and pressure using this concept?Short Answer 2 Marks May-2013 • PTU B-TECH
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May 2018 What is the concept of continuum? How density and pressure are defined using this concept?
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Dec 2016 What is the concept of continuum? How density and pressure are defined using this concept?
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Dec 2012 What is the concept of continuum? How density and pressure are defined using this concept.
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Why does free expansion have zero work transfer?Short Answer 2 Marks May-2013 • PTU B-TECH
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A Carnot engine with a fuel burning device as source and a heat sink cannot be treated as a reversible plant. Explain.Short Answer 2 Marks May-2013 • PTU B-TECH
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Why does entropy remain constant in a reversible adiabatic process?Short Answer 2 Marks May-2013 • PTU B-TECH
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May 2012 Why does entropy remain constant in a reversible adiabatic process?
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What is an air standard cycle? Why are such cycles conceived?Short Answer 2 Marks May-2013 • PTU B-TECH
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May 2016 What is an air standard cycle?
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May 2014 What do you mean by air standard cycles? What are the assumptions for air standard cycles?
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May 2008 What do you mean by air standard cycles?
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What do you understand by section modulus?Short Answer 2 Marks May-2013 • PTU B-TECH
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Explain centroidal axis and axis of symmetry with the help of an example.Short Answer 2 Marks May-2013 • PTU B-TECH
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Explain the terms machinability and maleability.Short Answer 2 Marks May-2013 • PTU B-TECH
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Explain different types of technological properties of materials.Short Answer 2 Marks May-2013 • PTU B-TECH
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Dec 2017 Explain any five properties of engineering materials.
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May 2012 What are technological properties of materials?
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Why would the name “thermostatics” be more appropriate than thermodynamics as applied to the science of thermal engineering?Short Answer 2 Marks May-2013 • PTU B-TECH
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An ideal gas requires 1150 kJ/kg of heat to raise its temperature from 20°C to 100°C, when heated at constant pressure. When heat is supplied to the same gas at constant volume, the heat requirement is 825 kJ for the same temperature range. Determine specific heat at constant pressure, specific heat at constant volume and adiabatic exponent.Long Answer 6 Marks May-2013 • PTU B-TECH
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Dec 2014 An ideal gas requires 1150 kJ/kg of heat to raise its temperature from 20°C to 100°C when heated at constant pressure. When heat is supplied to the same gas at constant volume, the heat requirement is 825 kJ for the same temperature range. Determine specific heat at constant pressure, specific heat at constant volume, and adiabatic exponent.
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How is polytropic exponent determined and within what limits can it change?Short Answer 2 Marks May-2013 • PTU B-TECH
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May 2018 How is polytropic exponent determined and within what limits it can range?
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Dec 2014 How is polytropic exponent determined and within what limits can it range?
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A gas of mass 1.5 kg undergoes a quasi-static expansion which follows a relationship p = a + bV, where a and b are constants. The initial and final pressures are 1000 kPa and 200 kPa respectively and the corresponding volumes are 0.20 m3 and 1.2 m3. The specific internal energy of the gas is given by the relation u = 1.5 pv - 85 kJ/kg, where p is the kPa and v is m3/kg. Calculate the net heat transfer and the maximum internal energy of the gas attained during expansion.Long Answer 6 Marks May-2013 • PTU B-TECH
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Air flows steadily at a rate of 0.4 kg/s through an air compressor, entering at 6 m/s with a pressure of 1 bar and a specific volume of 0.85 m3/kg, and leaving at 4.5 m/s with a pressure of 6.9 bar and a specific volume of 0.16 m3/kg. The internal energy of the air leaving is 88 kJ/kg greater than that of the air entering. Cooling water in the jacket surrounding the cylinder absorbs heat from the air at the rate of 59 W. Calculate the power required to drive the compressor and the inlet and outlet cross-sectional area.Long Answer 8 Marks May-2013 • PTU B-TECH
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A reversible heat engine interacts with three thermal reservoirs at 750K, 650K and 550K respectively. The engine absorbs 2400 kJ/min of energy as heat from the reservoir at 750K and does 400 kJ/min of net work. Determine the magnitude and direction of heat interactions of the engine with other two reservoirs.Long Answer 4 Marks May-2013 • PTU B-TECH
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A reversible engine operates between a source at 1200K and two sinks, one at 400K and another at 300K. The heat rejected at both the sinks is same. Determine the thermal efficiency of the engine.Long Answer 4 Marks May-2013 • PTU B-TECH
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An ideal Diesel cycle using air as the working fluid has a compression ratio of 16 and a cutoff ratio of 2. The intake conditions are 100 kPa, 20°C, and 2000 cm3. Using the cold air standard assumptions, determine: (i) the T and P at the end of each process, (ii) the net work output, (iii) thermal efficiency, (iv) the mean effective pressure.Comprehension 4 Marks May-2013 • PTU B-TECH
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May 2013 Determine the T and P at the end of each process for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the net work output for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the thermal efficiency for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the mean effective pressure for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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Determine the T and P at the end of each process for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.Long Answer 4 Marks May-2013 • PTU B-TECH
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May 2013 An ideal Diesel cycle using air as the working fluid has a compression ratio of 16 and a cutoff ratio of 2. The intake conditions are 100 kPa, 20°C, and 2000 cm3. Using the cold air standard assumptions, determine: (i) the T and P at the end of each process, (ii) the net work output, (iii) thermal efficiency, (iv) the mean effective pressure.
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May 2013 Determine the net work output for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the thermal efficiency for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the mean effective pressure for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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Determine the net work output for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.Short Answer 4 Marks May-2013 • PTU B-TECH
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May 2013 An ideal Diesel cycle using air as the working fluid has a compression ratio of 16 and a cutoff ratio of 2. The intake conditions are 100 kPa, 20°C, and 2000 cm3. Using the cold air standard assumptions, determine: (i) the T and P at the end of each process, (ii) the net work output, (iii) thermal efficiency, (iv) the mean effective pressure.
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May 2013 Determine the T and P at the end of each process for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the thermal efficiency for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the mean effective pressure for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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Determine the thermal efficiency for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.Short Answer 4 Marks May-2013 • PTU B-TECH
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May 2013 An ideal Diesel cycle using air as the working fluid has a compression ratio of 16 and a cutoff ratio of 2. The intake conditions are 100 kPa, 20°C, and 2000 cm3. Using the cold air standard assumptions, determine: (i) the T and P at the end of each process, (ii) the net work output, (iii) thermal efficiency, (iv) the mean effective pressure.
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May 2013 Determine the T and P at the end of each process for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the net work output for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the mean effective pressure for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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Determine the mean effective pressure for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.Short Answer 4 Marks May-2013 • PTU B-TECH
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May 2013 An ideal Diesel cycle using air as the working fluid has a compression ratio of 16 and a cutoff ratio of 2. The intake conditions are 100 kPa, 20°C, and 2000 cm3. Using the cold air standard assumptions, determine: (i) the T and P at the end of each process, (ii) the net work output, (iii) thermal efficiency, (iv) the mean effective pressure.
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May 2013 Determine the T and P at the end of each process for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the net work output for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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May 2013 Determine the thermal efficiency for an ideal Diesel cycle using air as the working fluid having a compression ratio of 16, a cutoff ratio of 2, and intake conditions of 100 kPa, 20°C, and 2000 cm3, using the cold air standard assumptions.
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In order to check the validity of the second law, 1 kg of water at temperature T1 is isobarically mixed with m2 kg of water at temperature T2 (T1 > T2). Determine the change in the entropy of the universe and find an expression for the same for equal mass of water. Also prove that the change is necessarily positive.Long Answer 8 Marks May-2013 • PTU B-TECH
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Locate the centroid of a T-section 10 cm x 10 cm x 2 cm.Short Answer 4 Marks May-2013 • PTU B-TECH
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Find the mass moment of inertia of circular ring of radius R and mass M.Short Answer 4 Marks May-2013 • PTU B-TECH
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Give a neat sketch of the theoretical and actual pV diagrams for a four stroke Petrol engine. Describe briefly the factors which account for deviations between these plots.Long Answer 4 Marks May-2013 • PTU B-TECH
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May 2018 Give a neat sketch of the theoretical and actual pV diagrams for a four stroke Petrol engine. Describe briefly the factors which account for deviations between these plots.
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May 2018 Give a neat sketch of the theoretical and actual pV diagrams for a four stroke Diesel engine. Describe briefly the factors which account for deviations between these plots.
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May 2014 Discuss the difference between theoretical and actual p–V diagrams for four stroke S.I. and C.I. engines.
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Dec 2014 Give a neat sketch of the theoretical and actual pV diagrams for a four stroke petrol engine. Describe briefly the factors which account for deviations between these plots.
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Dec 2012 Give a neat sketch of the theoretical and actual pV diagrams for a four stroke Diesel engine. Describe briefly the factors which account for deviations between these plots.
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Dec 2012 Give a neat sketch of the theoretical and actual pV diagrams for a four stroke Petrol engine. Describe briefly the factors which account for deviations between these plots.
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Dec 2011 Discuss the difference between theoretical and actual p–V diagrams for two stroke S.I. and C.I. engines.
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What is cast iron? What are its uses? What is the effect of carbon, silicon, sulphur and phosphorus on its properties?Long Answer 4 Marks May-2013 • 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.
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.