Solved question paper for EME May-2012 (B-TECH 1st-2nd)
Solved Question Paper
Elements of mechanical engineering May-2012
PTU • B-TECH • Mechanical Engineering • 1st-2nd • May-2012
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 the terms state, property, process and cycle.Short Answer 2 Marks May-2012 • PTU B-TECH
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Dec 2023 a) Explain the following terms : i) State, ii) Process, and iii) Cycle
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Dec 2017 Explain the terms state, path, process and cycle.
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Why does entropy remain constant in a reversible adiabatic process?Short Answer 2 Marks May-2012 • PTU B-TECH
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May 2013 Why does entropy remain constant in a reversible adiabatic process?
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List the conditions for which δQ - δW = dU ?Short Answer 2 Marks May-2012 • PTU B-TECH
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Show that enthalpy of a fluid before throttling is equal to after throttling.Short Answer 2 Marks May-2012 • PTU B-TECH
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May 2016 Show that the enthalpy of a fluid before throttling is equal to that after throttling.
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What is a heat pump? How is it different from refrigerator?Short Answer 2 Marks May-2012 • PTU B-TECH
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Dec 2018 What is a heat pump? How is it different from a refrigerator?
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May 2013 What are the differences between Refrigerator and Heat Pump?
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Define the following terms in relation to internal combustion engines: i) Dead centre ii) Stroke iii) Piston speed iv) Compression ratio.Short Answer 2 Marks May-2012 • PTU B-TECH
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How are internal combustion engines classified?Short Answer 2 Marks May-2012 • PTU B-TECH
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May 2016 How IC engines are classified?
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Dec 2012 What are the two basic types of internal combustion engines? What are the fundamental differences between the two?
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Dec 2011 How internal combustion engines can be classified on the basis of cylinder arrangement?
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What are kinematic links? How are they classified?Short Answer 2 Marks May-2012 • PTU B-TECH
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May 2017 What is kinematic chain?
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May 2017 State different types of basic kinematic chain.
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Dec 2014 What is kinematic chain?
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May 2013 Define link, kinematic chain with example.
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May 2011 Define kinematic link, kinematic pair and kinematic chain.
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Dec 2010 What is kinematic link.
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Dec 2009 Define kinematic link, kinematic pair and kinematic chain.
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Dec 2007 Define link, kinematic chain with example.
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What is law of machine?Short Answer 2 Marks May-2012 • PTU B-TECH
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Define resilience, proof resilience and modulus of resilience.Short Answer 2 Marks May-2012 • PTU B-TECH
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May 2018 Define resilience, proof resilience and modulus of resilience.
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May 2014 Define the following: i) Resilience, ii) Proof resilience, iii) Modulus of resilience.
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Show that polytropic specific heat is given by the expressionLong Answer May-2012 • PTU B-TECH
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A tank containing air is stirred by paddle wheel. The work input to the paddle wheel is 6000 kJ and the heat transfer to the surroundings from the tank is 200 kJ. Determine the change in internal energy of the system and the work done.Short Answer May-2012 • PTU B-TECH
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A steam turbine delivers 20 kW by receiving steam at 14 bar with u1 = 2730 kJ/kg, vS1 = 0.166 m3/kg and V1 = 120 m/s. Steam comes out of the turbine with u2 = 2340 kJ/kg, vS2 = 18.6 m3/kg and V1 = 330 m/s. The heat lost from the turbine is 20 kJ/kg. Neglecting the changes in potential energy, determine the work done per kg of steam flow through the turbine and steam flow through the turbine in kg per minute.Long Answer 8 Marks May-2012 • PTU B-TECH
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Derive the expression for change in entropy for constant volume process.Long Answer May-2012 • PTU B-TECH
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May 2012 Derive the expression for change in entropy for constant pressure process.
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May 2012 Derive the expression for change in entropy for adiabatic process.
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May 2012 Derive the expression for change in entropy for polytropic process.
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Derive the expression for change in entropy for constant pressure process.Long Answer May-2012 • PTU B-TECH
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May 2012 Derive the expression for change in entropy for constant volume process.
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May 2012 Derive the expression for change in entropy for adiabatic process.
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May 2012 Derive the expression for change in entropy for polytropic process.
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Derive the expression for change in entropy for adiabatic process.Long Answer May-2012 • PTU B-TECH
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May 2012 Derive the expression for change in entropy for constant volume process.
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May 2012 Derive the expression for change in entropy for constant pressure process.
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May 2012 Derive the expression for change in entropy for polytropic process.
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Derive the expression for change in entropy for polytropic process.Long Answer May-2012 • PTU B-TECH
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May 2012 Derive the expression for change in entropy for constant volume process.
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May 2012 Derive the expression for change in entropy for constant pressure process.
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May 2012 Derive the expression for change in entropy for adiabatic process.
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Air undergoes a cyclic process in a cylinder and piston arrangement. First the atmospheric air at 1 bar and 27°C is compressed adiabatically to 10 bar then expanded isothermally to initial pressure, then brought to initial conditions under constant pressure. Find out: (i) change in internal energy, (ii) change in enthalpy, (iii) heat transfer, (iv) work transfer.Long Answer 8 Marks May-2012 • PTU B-TECH
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An engine working on Otto cycle has a volume of 0.5m3, pressure 1 bar and temperature 27°C at the beginning of the compression stroke. At the end of the compression stroke, the pressure is 10 bar, 210 kJ of heat is added during the constant volume heating process. Calculate the pressures, temperatures and volumes at the salient points of the cycle. Also find the percentage clearance, efficiency, network done per cycle and mean effective pressure.Long Answer 8 Marks May-2012 • PTU B-TECH
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May 2023 An engine working on otto-cycle has a volume of 0.45m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210kJ of heat is added at constant volume. Determine: f) Ideal power developed by the engine if the number of working cycles per minute is 210. Assume the cycle id reversible.
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May 2023 An engine working on otto-cycle has a volume of 0.45m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210kJ of heat is added at constant volume. Determine: e) Mean effective pressure
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May 2023 An engine working on otto-cycle has a volume of 0.45m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210kJ of heat is added at constant volume. Determine: d) Network per cycle
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May 2023 An engine working on otto-cycle has a volume of 0.45m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210kJ of heat is added at constant volume. Determine: c) Efficiency
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May 2023 An engine working on otto-cycle has a volume of 0.45m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210kJ of heat is added at constant volume. Determine: b) Percentage clearance
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May 2023 An engine working on otto-cycle has a volume of 0.45m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210kJ of heat is added at constant volume. Determine: a) Pressure, temperature and volume at a salient point in the cycle
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Dec 2020 An engine working on otto-cycle has a volume of 0.45 m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210 kJ of heat is added at constant volume. Determine: a) Pressure, temperature and volume at a salient point in the cycle
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Dec 2020 An engine working on otto-cycle has a volume of 0.45 m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210 kJ of heat is added at constant volume. Determine: b) Percentage clearance
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Dec 2020 An engine working on otto-cycle has a volume of 0.45 m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210 kJ of heat is added at constant volume. Determine: c) Efficiency
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Dec 2020 An engine working on otto-cycle has a volume of 0.45 m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210 kJ of heat is added at constant volume. Determine: d) Network per cycle
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Dec 2020 An engine working on otto-cycle has a volume of 0.45 m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210 kJ of heat is added at constant volume. Determine: e) Mean effective pressure
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Dec 2020 An engine working on otto-cycle has a volume of 0.45 m^3, pressure 1 bar and temperature 30°C at the beginning of compression stroke. At the end of compression stroke, the pressure is 11 bar. 210 kJ of heat is added at constant volume. Determine: f) Ideal power developed by the engine if the number of working cycles per minute is 210. Assume the cycle is reversible.
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Describe the working principle of a two stroke petrol engine with a neat diagram.Long Answer May-2012 • PTU B-TECH
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Dec 2023 Explain the construction and working of four stroke petrol engine.
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Dec 2019 Explain the working of two stroke petrol engine giving neat sketch.
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Dec 2018 Explain the working of a two-stroke petrol engine with the help of neat sketches. What are the demerits of two-stroke engines?
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May 2016 Write short notes on working of two stroke petrol engine.
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May 2013 Discuss briefly the working of a 4 Stroke Petrol engine.
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Dec 2011 Explain the working of two stroke C.I. engine with the help of neat sketches.
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May 2007 Explain the working of two stroke IC engine with neat sketches.
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Dec 2007 Explain the working of four stroke IC engine with neat sketches.
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Sketch and describe a four bar chain mechanism.Long Answer May-2012 • PTU B-TECH
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Describe with a neat diagram the following lifting machines: wheel and differential axle.Long Answer May-2012 • PTU B-TECH
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Describe with a neat diagram the following lifting machines: worm and worm wheel.Long Answer May-2012 • PTU B-TECH
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Describe with a neat diagram the following lifting machines: third system of pulleys.Long Answer May-2012 • PTU B-TECH
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A bar 100 cm in length is subjected to an axial pull, such that the maximum stress is equal to 150 MN/m2. Its area of cross section is 2 cm2 over a length of 95 cm and for the middle 5 cm length it is only 1 cm2. If E = 200 GN/m2, calculate the strain energy stored in bar.Long Answer 8 Marks May-2012 • 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.