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.

Solved Questions

Solved
  1. Define the terms state, property, process and cycle.
    Short Answer 2 Marks May-2012 • PTU B-TECH
  2. Why does entropy remain constant in a reversible adiabatic process?
    Short Answer 2 Marks May-2012 • PTU B-TECH
  3. List the conditions for which δQ - δW = dU ?
    Short Answer 2 Marks May-2012 • PTU B-TECH
  4. Show that enthalpy of a fluid before throttling is equal to after throttling.
    Short Answer 2 Marks May-2012 • PTU B-TECH
  5. What is a heat pump? How is it different from refrigerator?
    Short Answer 2 Marks May-2012 • PTU B-TECH
  6. 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
  7. How are internal combustion engines classified?
    Short Answer 2 Marks May-2012 • PTU B-TECH
  8. What are kinematic links? How are they classified?
    Short Answer 2 Marks May-2012 • PTU B-TECH
  9. What is law of machine?
    Short Answer 2 Marks May-2012 • PTU B-TECH
  10. Define resilience, proof resilience and modulus of resilience.
    Short Answer 2 Marks May-2012 • PTU B-TECH
  11. Show that polytropic specific heat is given by the expression
    Long Answer May-2012 • PTU B-TECH
  12. 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
  13. 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
  14. Derive the expression for change in entropy for constant volume process.
    Long Answer May-2012 • PTU B-TECH
  15. Derive the expression for change in entropy for constant pressure process.
    Long Answer May-2012 • PTU B-TECH
  16. Derive the expression for change in entropy for adiabatic process.
    Long Answer May-2012 • PTU B-TECH
  17. Derive the expression for change in entropy for polytropic process.
    Long Answer May-2012 • PTU B-TECH
  18. 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
  19. 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
  20. Describe the working principle of a two stroke petrol engine with a neat diagram.
    Long Answer May-2012 • PTU B-TECH
  21. Sketch and describe a four bar chain mechanism.
    Long Answer May-2012 • PTU B-TECH
  22. Describe with a neat diagram the following lifting machines: wheel and differential axle.
    Long Answer May-2012 • PTU B-TECH
  23. Describe with a neat diagram the following lifting machines: worm and worm wheel.
    Long Answer May-2012 • PTU B-TECH
  24. Describe with a neat diagram the following lifting machines: third system of pulleys.
    Long Answer May-2012 • PTU B-TECH
  25. 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.