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

Solved Question Paper

Elements of mechanical engineering Dec-2012

PTU • B-TECH • Mechanical 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. State the conditions for a process to be reversible.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  2. What do you understand by thermodynamic property and thermometric substance?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  3. Why there are two values of specific heat for a gas?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  4. Explain the term reversibility as applied to a thermodynamic process.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  5. Comment on the statement: The entropy of the universe tends to be maximum.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  6. An engine working on Otto cycle has temperatures 300 K and 600 K at the beginning and end of the compression stroke. Determine the compression ratio and air standard efficiency.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  7. List the various advantages of internal combustion engines over external combustion engines.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  8. Explain the terms isotropy and homogeneity.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  9. Define a smart material.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  10. Define first moment of an area about an axis.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  11. Differentiate between temperature, heat and internal energy.
    Short Answer 3 Marks Dec-2012 • PTU B-TECH
  12. A cylinder of volume 0.1 m3 contains nitrogen gas at 1.01 bar and 20°C. If 0.5 kg of nitrogen is now pumped into cylinder, calculate the new pressure when the cylinder has returned to initial temperature. The molar mass of nitrogen is 28 kg/mol. Assume nitrogen to be perfect gas.
    Long Answer 5 Marks Dec-2012 • PTU B-TECH
  13. Show that internal energy I is a function of temperature only.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  14. The following is the equation which relates internal energy u, pressure p, and volume v for several gases: U = a + bpV. Where a and b are constants. Prove that for a reversible adiabatic process, pVγ = C where γ = b+1/b.
    Long Answer 6 Marks Dec-2012 • PTU B-TECH
  15. A steady flow thermodynamic system receives fluid at a rate of 6 kg/min with an initial pressure of 2 bar, velocity 150 m/s, internal energy 800 kJ/kg and density 27 kg/m3. The fluid leaves the system with a final pressure of 8 bar, velocity 200 m/s, internal energy 800 kJ/kg and density 5 kg/m3. If fluid receives 80 kJ/kg of heat during passing through the system and rises through 60 m, determine the work done during the process.
    Long Answer 8 Marks Dec-2012 • PTU B-TECH
  16. Two Carnot engines working in series between the source and sink temperatures of 550 K and 350 K. If both engines develop equal power, determine intermediate temperature.
    Short Answer 4 Marks Dec-2012 • PTU B-TECH
  17. A cyclic heat engine operates between 800°C and 30°C. What is the least rate of heat rejection in kW net output of engine?
    Short Answer 4 Marks Dec-2012 • PTU B-TECH
  18. A gas engine working on Otto cycle has a compression ratio 7. The pressure and temperature at the start of compression is 0.98 bar and 328K, the air gas ratio is 1.2:1. If the heating value of the gas is 3850 kJ/m3 and specific heat at constant volume is 0.719 kJ/kg-K, calculate the thermal efficiency, mean effective pressure and work done per kg of the mixture.
    Long Answer 8 Marks Dec-2012 • PTU B-TECH
  19. One kg of water at 273 K is brought into contact with a heat reservoir at 363 K. When the water has reached at 363 K, find: i) Change in entropy of water, ii) Change in entropy of reservoir, iii) Change in entropy of universe.
    Comprehension 6 Marks Dec-2012 • PTU B-TECH
  20. If the water is heated from 273 K to 363 K by first bringing it in contact with a reservoir at 313 K and then with a reservoir at 363 K, what will be the entropy change of the universe?
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  21. Find the mass moment of inertia of solid cone about its axis of rotation.
    Long Answer 6 Marks Dec-2012 • PTU B-TECH
  22. Determine the polar moment of inertia of a hollow circular section whose external diameter is 10 cm and thickness is 1 cm.
    Short Answer 2 Marks Dec-2012 • PTU B-TECH
  23. 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.
    Long Answer 4 Marks Dec-2012 • PTU B-TECH
  24. What are ceramic materials? Name some of important ceramic materials. State advantages of ceramic materials.
    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?

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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.