Download PTU B.Tech 2020 March ME 7th and 8th Sem Industrial Tribology Question Paper

FirstRanker.com

Roll No. Total No. of Pages : 02
Total No. of Questions : 09

--- Content provided by⁠ FirstRanker.com ---

--- Content provided by‌ FirstRanker.com ---

INSTRUCTION TO CANDIDATES :

1. SECTION-A is COMPULSORY consisting of TEN questions carrying TWO marks each.
2. SECTION-B contains FIVE questions carrying FIVE marks each and students have to attempt any FOUR questions.
3. SECTION-C contains THREE questions carrying TEN marks each and students have to attempt any TWO questions.

SECTION-A

--- Content provided by​ FirstRanker.com ---

1. Answer briefly :
   1. Define Wear.
   2. Describe various types of lubricants.
   3. Illustrate hydrostatic lubrication.
   4. Briefly describe Archard’s equation.
   5. List any two methods of testing lubricants.

   --- Content provided by‍ FirstRanker.com ---

   6. Differentiate between rubbing and sliding motion.
   7. Describe Sommerfield number.
   8. List any two methods of studying surfaces.
   9. List out the additives used in lubricants.
   10. Why surface-coatings are necessary in Industrial applications?

   --- Content provided by FirstRanker.com ---

SECTION-B

2. Describe the following terms :
   1. Surface roughness
   2. Waviness
   3. Form errors

   --- Content provided by‌ FirstRanker.com ---

3. Discuss the laws of rolling friction. Suggest some laws of siding friction analogous to those of rolling friction.
4. Explain any two methods of testing the lubricants.
5. 1. Can hybrid hydrostatic and hydrodynamic bearings be developed and used to advantage?
   2. Give examples of operating conditions under which the application of hydrostatic bearings would be necessary or highly desirable.

   --- Content provided by FirstRanker.com ---

6. Describe various properties of liquid and grease lubricants.

SECTION-C

7. A hydrostatic thrust bearing of a turbine generator is designed for a load of 24 KN. The outside diameter is 0.2 m and diameter of recess is 0.1 m. The film thickness is to be 0.1 mm.
   1. Determine the recess pressure and volume flow required if the oil used is of 0.1 cP.
   2. Assuming P_r/P_s = 0.5, determine the stiffness of bearing. Generator speed = 750 rpm. Here P_r is the recess pressure and P_s is supply pressure.

   --- Content provided by⁠ FirstRanker.com ---

8. 1. What are the two conditions for the occurrence of hydrodynamic lubrication?
   2. Describe the term elasto hydrodynamic films and their effects.
   3. Describe the categories of boundary and extreme pressure lubrication.

--- Content provided by‍ FirstRanker.com ---

9. Describe and Sketch various friction and wear measurement methods.

NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any page of Answer Sheet will lead to UMC against the Student.

FirstRanker.com