June 2008 Question Paper with Model Answers

BE (First/Second) Semester Exam

(Common to all Branches)

Time: 3 hrs

Maximum Marks: 100

Minimum Marks: 35

Note: Attempt FIVE questions, selecting ONE questions from each unit. Suitably assume any missing data. All questions carry equal marks.

Unit-I

1. a) Explain the stress-strain diagrams of mild steel and cast iron with neat sketches. 10 marks

Ans: Refer Page 17 of BME - Basant Agrawal, Wiley India
1. b) Write short notes on the following: (i) Grey cast iron (ii) Alloy steels 10 marks
Ans: Refer Page 3 and 4 of BME - Basant Agrawal, Wiley India

Or

2. (a) Explain the following briefly: (i) Hardness (ii) Ductility (iii) Fatigue strength (iv) Tensile strength 10 marks

Ans: Refer Page 12 and 13 of BME - Basant Agrawal, Wiley India
2. (b) Discuss the effect of the following alloying elements in steel. (i) Chromium (ii) Nickel (iii) Tungesten (iv) Sulphur 10 marks

Ans: Refer Page 5 of BME - Basant Agrawal, Wiley India:

Unit-II

3.(a) Write short notes on the following: (i) Errors of measurement (ii) Uncertainity analysis 10 marks

Ans: Refer Page 71-73 of BME - Basant Agrawal, Wiley India
3.(b) Explain the construction, working and uses of a micrometer. 10 marks
Ans: Refer Page 82-83 of BME - Basant Agrawal, Wiley India

Or

4. (a) Write short notes on the following: (i) Surface Plate (ii) Sine Bar 10 marks

Ans: Refer Page 86-87 of BME - Basant Agrawal, Wiley India
4. (b) Explain the construction and working principle of a lathe machine with neat sketch. 10 marks

Ans: Refer Page 94 and 96 of BME - Basant Agrawal, Wiley India

Unit-III

5. (a) State and explain Bernoulli's equation for incompressible fluids. 10 marks

Ans: Refer Page 124-125 of BME - Basant Agrawal, Wiley India
5. (b) Write short notes on the following: (i) Viscous flow (ii) Turbulent flow 10 marks

Ans: Refer Page 132-133 of BME - Basant Agrawal, Wiley India

Or

6. (a) Explain the working principle of a fluid coupling. 10 marks

Ans: Refer Page 139 of BME - Basant Agrawal, Wiley India
6. (b) How pumps ar classified? Explain. 10 marks

Ans: Refer Page 141 of BME - Basant Agrawal, Wiley India

Unit-IV

7. (a) State and explain second law of thermodynamics. 10 marks

Ans: Refer Page 172-173 of BME - Basant Agrawal, Wiley India
7. (b) What is boiler draught? Derive an expression for chimney height. 10 marks

Ans: Refer Page 238-241 of BME - Basant Agrawal, Wiley India

Or

8. Explain the following: (i) COP (ii) Boiler efficiency (iii) Natural draught (iv) Entropy 5 marks each

Ans: Refer Page (i) 265 (ii) 229 (iii) 238 (iv) 192 of BME - Basant Agrawal, Wiley India

Unit -V

9. (a) Explain Carnot cycle and derive an expression for efficiency of Carnot cycle. 10 marks

Ans: Refer Page 300-301 of BME - Basant Agrawal, Wiley India
9. (b) What is an indicator diagram? Explain hypothetical and actual indicator diagram of a steam engine. 10 marks

Ans: Refer Page 278-279 of BME - Basant Agrawal, Wiley India

Or

10. (a) An air standard Otto cycle is designed to operating following data:

Maximum cycle pressure and temperature : 5 MPa and 2250 K

Minimum cycle pressure and temperature : 0.1 MPa and 300 K

Determine the net work output per unit mass of working fluid and the thermal efficiency. 10 marks

Ans: [508.8 kJ/kg; 53.18%]

Also Refer Page 325 of BME - Basant Agrawal, Wiley India

10. (b) Explain Diesel cycle and derive an expression for efficiency of Diesel cycle. 10 marks

Ans: Refer Page 313-315 of BME - Basant Agrawal, Wiley India