Jan-2019

January-2019

Elements of Mechanical Engineering (18ME15)

Sem-I

Time-3 Hours

Maximum Marks- 100

Note : 1. Answer Five full questions, chosing ONE full question from each module.

2. Use of Thermodynamics data hand book is permitted.

Module-I

Q.1. a) Explain briefly the principle of conversion of solar energy directly into electrical energy in a solar cell. [10 M]

b) Write a note on wind energy and its conversion. [10 M]

Q.2 (a) Explain 1st law of thermodynamics. List the similarities and dissimilarities between work and heat.[10 M]

b) Define the following terms in relation to steam.

i) Dryness fraction

ii) latent heat

iii) Degree of superheat

iv) saturation temperature    [10 M]

Module-2

Q.3. a) Differentiate between water tube boiler and fire tube boiler. [04 M]

b) List the boiler mountings and accessories and also mention their uses. [06 M]

c) with neat sketch explain the working of Babcock and Wilcox boiler. [10 M]

OR

Q.4 a) with a neat sketch explain the working of Pelton Wheel. [10 M]

b) With a neat sketch explain the working of a Reciprocating pump, state the advantages and uses. [10 M]

MODULE-III

Q.5. a) Differentiate between two-stroke and four stroke engine. [04 M]

b) explain with neat sketch construction and working of 4-stroke diesel engine with the help of theoretical P-V-diagram. [10 M]

c) A four stroke single cylinder Diesel engine piston diameter 250 mm and stroke 400 mm. The mean effective pressure is 4 -bar and speed is 500 rpm. Diameter of the brake drum is 1000 mm. The effective brake load is 400 N. Find IP, BP and FP. [06 M]

OR

Q.6. a) What are the properties of good refrigerant? [04 M]

b) Explain with neat sketch working principle of vapour compression refrigeration. [10 M]

c) Explain the following. [06 M]

i) Refrigeration effect

ii) Ton of refrigeration

iii) COP

Module- IV

Q.7. write a note on application of ferrous and non-ferrrous alloys. [06 M]

b) Define composite material. State the advantages and applications of composite material. [05 M]

c) differentiate between soldering, brazing and welding. [09 M]

OR

Q.8. a) Differentiate between open and crossed belt drive. [06 M]

b) Enumerate the advantages and disadvantages of gear drive over belt drive. [06 M]

c) Derive an equation for length of belt in open belt drive. [08 M]

Module-v

Q.9. a) Explain the following operation on lathe with suitable sketches :

i) Turning

ii) Knurling

iii) Facing

iv) Thread cutting   [10 M]

b) Explain the following operation on milling machine with suitable sketches: [10 M]

i) Form milling

ii) Angular milling

iii) Gang milling.

OR

Q.10. a) Differentiate between open loop and closed loop systems. [06 M]

b) Define robot. write down industrial applications of robot. [04 M]

c) Explain the components of CNC with a block diagram. [10 M]