Solved question paper for EME Dec-2012 (B-TECH 1st-2nd)

Solved Question Paper

Elements of mechanical engineering Dec-2012

PTU • B-TECH • Civil Engineering • 1st-2nd • Dec-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. Why are shape, colour and odour irrelevant in thermodynamics?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  2. Set up an expression for the displacement work done during an arbitrary process.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  3. How does a control volume differ from a system?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  4. Comment on the validity of the statement: “All reversible engines operating between the same two thermal reservoirs have the same efficiency.”
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  5. Write the expression for heat transfer which is equivalent to the term pdv for work transfer.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  6. What is cutoff ratio? How does it affect the air standard efficiency of a Diesel cycle?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  7. What are the two basic types of internal combustion engines? What are the fundamental differences between the two?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  8. How does a machine help to achieve gain in force?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  9. State the principle of superposition and point out its utility.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  10. Define direct, shear and volumetric stresses and corresponding strains.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  11. Determine the molecular weight of a gas if its specific heats are cp = 2.286 kj/kg – K and cv = 1.768 kj/kg – K.
    Short Answer 4 Marks Dec-2012 • PTU B-TECH
  12. One mole of an ideal gas at 10 bar and 300 K at constant pressure till the volume is doubled and then it is allowed to expand at constant temperature till the volume is doubled again. Calculate the work done by the gas.
    Long Answer 4 Marks Dec-2012 • PTU B-TECH
  13. Show that when an ideal gas is compressed in a piston cylinder assembly according to polytropic law pV n = C, the heat rejected, increase in internal energy and work done are in the ratio (γ–n) : (n – 1):(γ – 1).
    Long Answer 4 Marks Dec-2012 • PTU B-TECH
  14. What is the concept of continuum? How density and pressure are defined using this concept.
    Short Answer 4 Marks Dec-2012 • PTU B-TECH
  15. Make an energy analysis of a turbine.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  16. Steam enters a steam turbine at 5m elevation, at a velocity of 30m/s, enthalpy 2950 kJ/kg. At exit the velocity is 600 m/s, enthalpy 2200 kJ/kg and elevation 2m, 75 kJ/kg of heat is lost to the surroundings. Calculate the work output of the turbine.
    Long Answer 6 Marks Dec-2012 • PTU B-TECH
  17. A reversible engine operates between three heat reservoirs X, Y, and Z. The engine receives equal amount of heat from reservoir X and Y at temperatures Tx and Ty respectively and rejects heat to a reservoir Z at temperature Tz. If the efficiency of the engine is β times the efficiency of a reversible engine operating between two reservoirs X and Z only, show that Tx/Ty = 2(1–β) Tx/Tz + (2β–1).
    Long Answer 8 Marks Dec-2012 • PTU B-TECH
  18. A six cylinder four stoke Diesel engine has compression ratio 16 to 1. The bore and stroke are 200 mm and 250 mm respectively and the engine runs at 1200 rpm. Ambient conditions are 100kPa and 300 K. Calculate the power produced if the cut off is 10% of the stroke. What is the maximum temperature?
    Long Answer 8 Marks Dec-2012 • PTU B-TECH
  19. A substance is initially at 0.5 MPa pressure and 0.25m3. It is compressed by an isentropic process so that the final pressure is 3 MPa. Find changes in enthalpy, internal energy and entropy, and heat and work interactions during the process.
    Long Answer 8 Marks Dec-2012 • PTU B-TECH
  20. A vertical circular copper bar 20mm diameter and 3m long carries a tensile load of 200kN. Calculate the elongation, decrease in diameter and the volumetric strain.
    Long Answer 8 Marks Dec-2012 • PTU B-TECH
  21. 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 Dec-2012 • PTU B-TECH
  22. Sketch and describe the working of crank and slotted lever type quick return mechanism.
    Long Answer 4 Marks Dec-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.