B.E./B.Tech. Degree Examination, May/June 2009

B.E./B.Tech. Degree Examination, May/June 2009

Fifth Semester - Mechanical Engineering (Regulation 2004) 

ME 1305 - APPLIED HYDRAULICS AND PNEUMATICS

Time: Three hours

Answer ALL questions.

Maximum: 100 marks

Part A - (10 × 2 = 20 marks)

1. List out any four desirable properties of hydraulic fluids.

Ans. Refer Chapter 2, Q. No. 21, Two Marks Q&A, Page No. 2.23.

2. Give the symbol of variable vane pump and pressure compensated flow control valve. 

Ans. Refer Chapter 6, Q. Nos. 6.23 & 6.33, Two Marks Q&A, Page Nos.6.51 & 6.52. 

3. A positive displacement pump has an overall efficiency of 87% and volumetric efficiency of 93%, what is its mechanical efficiency? 

Ans. Refer Chapter 4, Q. No. 32, Two Marks Q&A, Page No. 4.48.

4. What are the advantages of telescope cylinders?

Ans. Refer Chapter 5, Q. No. 12, Two Marks Q&A, Page No. 5.31. 

5. What is the function of a sequence valve?

Ans. Refer Chapter 6, Q. No. 25, Two Marks Q&A, Page No. 6.50.

6. Why weight loaded type accumulator is undesirable for mobile equipment? 

Ans. Refer Chapter 9, Q. No. 7, Two Marks Q&A, Page No. 9.34. 

7. Give the symbol for an electro-pneumatic 3 position 4 way DC valve. 

Ans. Refer Chapter 6, Q. No. 14, Two Marks Q&A, Page No. 6.48. 

8. Why a lubricator should be used in pneumatic system.

Ans. Refer Chapter 11, Q. No. 15, Two Marks Q&A, Page No. 11.22. 

9. Where can fluidics be applied?

Ans. Refer Chapter 15, Q. No. 4, Two Marks Q&A, Page No. 15.28. 

10. List the components present in PLC.

Ans. Refer Chapter 15, Q. No. 15.9, Two Marks Q&A, Page No. 15.21. 

Part B - (5 × 16 = 80 marks)

11. (a) (i) Describe any four advantages of fluid power systems.

Ans. Refer Chapter 1, Section 1.5, Page No.1.5.

(ii) Differentiate between laminar and turbulent flow with examples. 

Ans. Refer Chapter 3, Section 3.6, Page No.3.9.

 [OR]

(b) (i) Describe any four applications of fluid power systems.

Ans. Refer Chapter 1, Section 1.6, Page No.Ì.7.

(ii) Draw a schematic layout of hydraulic power pack with symbols.

Ans. Refer Chapters 16, Section 16.18, Page Nos.16.33.

12. (a) Draw a neat sketch of an unbalanced type vane pump, explain its construction and operation and also show how the same can operate as a reversible pump. Also given its standard graphical symbol.

Ans. Refer Chapter 4, Section 4.13, Page No.4.17.

[OR]

(b) (i) Describe the working of an external gear pump with a diagram.

Ans. Refer Chapter 4, Section 4.7, Page No.4.8.

(ii) Explain briefly about the fluid motors.

Ans. Refer Chapter 12, Section 12.9, Page No.12.3.

13. (a) (i) Sketch and explain commonly used 3-position 4-way direction control valves.

Ans. Refer Chapter 12, Section 12.3.4, Page No.12.4.

(ii) With the help of circuit diagrams, illustrate the application of accumulators. 

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

 [OR]

(b) (i) Design and explain the working of a regenerative circuit.

Ans. Refer Chapter 8 (or 14), Section 8.5 (or 14.8), Page No.8.6 (or 14.12). 

(ii) Design and explain the working of a sequencing circuit.

Ans. Refer Chapter 8 Section 8.10, Page No.8.13.

14. (a) (i) Draw and explain the functions of an air filter.

Ans. Refer Chapter 11, Section 11.7, Page No.11.11.

(ii) Draw and explain the functions of pneumatic check valve. 

Ans. Refer Chapter 12, Section 12.4.2, Page No.12.5.

[OR]

 (b) Design a pneumatic circuit for the following sequence using cascade method: A+B+B-A-C+C-

Ans. Refer Chapter 13, Example 13.1, Page No.13.19.

15. (a) Explain with a neat sketch construction and operation of an electro-hydraulic servo valve. Also, deduce the expression for its open loop gain.

Ans. Refer Chapter 6, Section 6.25, Page No.6.32.

[OR]

(b) (i) Explain the working of fluidic amplifiers.

Ans. Fluidic amplifiers are nothing but flips-flops. So refer Chapter 5, Section 15.4,. Page No.15.4.

(ii) Describe PLC applications in fluid power control. 

Ans. Refer Chapter 15, Section 15.8, Page No.15.20.