NR

Code No: NR211802

1. (a) Explain the various mechanisms of heat transfer.

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II B.Tech I Semester Supplimentary Examinations, May/Jun 2009 FURNACE TECHNOLOGY AND PYROMETRY (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????

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(b) Explain the various differences between steady state and variable thermal conduction. [8+8] 2. (a) Derive Newton-Rikman law for a fluid in contact with a solid boundary.

(b) Describe various types of heat exchangers based on temperature distribution. [8+8] 3. (a) Explain the concept of black body.

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(b) Discuss about emissivity of materials.

(c) Explain the mechanism of heat transfer by radiation. 4. Write short notes on the following:

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(a) Thermal diffusivity

[5+6+5]

(b) Thermal efficiency of insulation

(c) Unsteady state heat conduction.

[6+5+5]

5. (a) Explain the construction of a tubular furnace for sintering purpose, heated by electric resistance principle. Discuss the advantages, limitations and applications of the above furnace.

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(b) Discuss the factors influencing the selection of frequency for an induction furnace. [11+5]

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6. What are the various types of thermocouples available. Give composition of the materials used for the construction of thermocouples. What are the advantages, disadvantages and applications of each one of them. Also indicate their temperature ranges. [16] 7. (a) What is a resistance thermometer? Explain the working principle of resistance thermometer. Name some of the applications of resistance thermometer. (b) Explain the working principle, constructional details and operation of a resistance thermometer. [8+8]

8. (a) What are the sources of error in radiation pyrometers? Explain them. (b) Discuss in detail about pyro-optical pyrometer. ????? 1 of 1

[7+9]