B.E./B.Tech. Degree Examination, Nov/Dec 2018

B.E./B.Tech. Degree Examination, Nov/Dec 2018 

Mechanical Engineering (Regulations 2008)

ME 2305: HYDRAULICS AND PNEUMATICS

Time: Three hours

Maximum: 100 marks

Answer ALL questions. 

Part A - (10 × 2 = 20 marks)

1. Why is hydraulic power especially used for heavy work?

Ans. Refer Chapter 1, Q. No. 12, Two Marks Q&A, Page No. 1.24.

2. Name any four draw backs of fluid power systems.

Ans. Refer Chapter 1, Q. No. 8, Two Marks Q&A, Page No. 1.23. 

3. Differentiate double rod and tandem cylinder.

Ans. Refer Chapter 5, Q. No. 15, Two Marks Q&A, Page No. 5.32.

4. Why do screw pumps generate less noise while running?

Ans. Refer Chapter 4, Q. No. 15, Two Marks Q&A, Page No. 4.46. 

5. Explain briefly the non-separator type gas loaded accumulator. 

Ans. Refer Chapter 9, Q. No. 9, Two Marks Q&A, Page No. 9.34. 

6. What is ladder diagram?

Ans. Refer Chapter 14, Q. No. 13, Two Marks Q&A, Page No. 14.17. 

7. What are the advantages of using sequencing circuit?

Ans. Refer Chapter 8, Q. No.-6, Two Marks Q&A, Page No. 8.37.

8. Where speed control circuits are required?

Ans. Refer Chapter 8, Q. No. 10, Two Marks Q&A, Page No. 8.37. 

9. What is meant by servo systems?

Ans. Refer Chapter 6, Q. No. 34, Two Marks Q&A, Page No. 6.52.

10. List the uses of ladder diagrams.

Ans. Refer Chapter 14, Q. No. 14, Two Marks Q&A, Page No. 14.17.

Part B - (5 × 16 = 80 marks)

11. (a) (i) Explain the various types of fluid power system.

Ans. Refer Chapter 1, Section 1.2.2, Page No. 1.2.

(ii) Write the advantages of fluid power systems.

Ans. Refer Chapter 1, Section 1.5, Page No. 1.5. [OR]

(b) Write notes on

(i) Neutralization number.

Ans. Refer Chapter 2, Section 2.4.20, Page No. 2.12. 

(ii) Frictional losses in laminar and turbulent flow.

Ans. Refer Chapter 3, Section 3.14, Page No. 3.14.

12. (a) (i) Describe the working principle pressure compensated variable displacement vane pump.

Ans. Refer Chapter 4, Section 4.14, Page No. 4.18.

 (ii) Mention the role of a pump in a hydraulic system and how it is classified. 

Ans. Refer Chapter,4, Section 4.2, Page No. 4.1.

[OR]

(b) (i) Explain the 'end cushion' provided in hydraulic cylinder with a neat sketch. 

Ans. Refer Chapter 5, Section 5.5, Page No. 5.6.

(ii) How torque is developed in a gear motor? Explain with neat sketch. 

Ans. Refer Chapter 5, Section 5.11, Page No. 5.13.

13. (a) Sketch and explain commonly used 3-position 4-way direction control valves. Also state the applications for closed center, open center and tandem center valves. 

Ans. Refer Chapter 6, Sections 6.10.1 & 6.10.2, Page No. 6.15.

[OR]

(b) With the help of circuit diagrams. Explain the application of accumulator. Also illustrate its types. 

Ans. Refer Chapter 9, Section 9.10, Page No. 9.10.

14. (a) Draw a pneumatic circuit by cascade method for following sequence of operation: A+ B+ B ̄ A ̄ where A and B are the two cylinders and + indicates extension and – indicates retraction of the cylinder.

Ans. Refer Chapter 13, Example 13.3, Page No. 13.22.

[OR]

(b) Briefly explain FRL unit with neat sketch.

Ans. Refer Chapter 11, Section 11.10, Page No. 11.15.

15. (a) (i) Explain the working of electro hydraulic servo systems with neat sketch.

Ans. Refer Chapter 6, Section 6.25.8, Page No. 6.37.

(ii) What is meant by fluidics? Name some fluidic devices and is uses. 

Ans. Refer Chapter 15, Section 15.2, Page No. 15.1.

 [OR]

(b) (i) Two double-acting pneumatic cylinders A and B, with double solenoid valves have to work in the following sequences. A+ B+, A-, B-. Draw a ladder diagram and indicate the input and output devices. Both the cylinders have limit switches.

Ans. Refer Chapter 13, Example 13.5, Page No. 13.23.

(ii) Write short notes on failure and trouble shooting in pneumatic circuits.

Ans. Refer Chapter 17, Section 17.7, Page No. 17.16.