Download PTU B-Tech AE 2020 Dec 5th Sem 70486 Heat Transfer Question Paper

Download PTU (I.K.Gujral Punjab Technical University (IKGPTU)) B-Tech (Bachelor of Technology) (AE)-Automobile Engineering 2020 December 5th Sem 70486 Heat Transfer Previous Question Paper

Roll No.
Total No. of Pages : 02
Total No. of Questions : 18
B.Tech. (AE) (2012 to 2017) (Sem.?5)
HEAT TRANSFER
Subject Code : BTAE-503
M.Code : 70486
Time : 3 Hrs. Max. Marks : 60
INST RUCT IONS T O CANDIDAT ES :
1 .
SECT ION-A is COMPULSORY cons is ting of TEN questions carrying TWO marks
each.
2 .
SECT ION-B c ontains F IVE questions c arrying FIVE marks eac h and s tud ents
have to atte mpt any FOUR q ues tions.
3 .
SECT ION-C contains THREE questions carrying T EN marks e ach and s tudents
have to atte mpt any T WO questio ns.
SECTION-A
Write briefly :
1.
What are the modes of heat transfer in a boiler?
2.
Write basic one-dimension equation for conduction heat transfer with internal heat
generation.
3.
What do you mean by critical thickness of insulation?
4.
What is a fin effectiveness?
5.
What is NTU?
6.
Why counter flow heat exchanger is more effective than parallel flow?
7.
What do you mean opaque bodies?
8.
Explain Stefan Boltzmann's law?
9.
Which dimensionless number is more significant in turbulent flow?
10. What are grey and black bodies?
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SECTION-B
11. What is thermal diffusivity? Discuss its significance.
12. One face of a copper plate 3 cm thick is maintained at 400 ?C, and the other face is
maintained at 100?C. How much heat is transferred through the plate? Take thermal
conductivity for copper is 370W/m?C at 250?C.
13. Two infinite black plates at 800?C and 300?C exchange heat by radiation. Calculate the
heat transfer per unit area.
14. Drive the relationship for the heat transfer from the fin losing heat from tip.
15. What is thermal boundary layer?
SECTION-C
16. A certain material 2.5 cm thick, with a cross-sectional area of 0.1 m2, has one side
maintained at 35?C and the other at 95?C. The temperature at the centre plane of the
material is 62?C, and the heat flow through the material is 1 kW. Obtain an expression
for the thermal conductivity of the material as a function of temperature.
17. A glass plate 30 cm square is used to view radiation from a furnace. The transmissivity of
the glass is 0.5 from 0.2 to 3.5 m. The emissivity may be assumed to be 0.3 up to
3.5 m and 0.9 above that. The transmissivity of the glass is zero, except in the range
from 0.2 to 3.5 m. assuming that the furnace is a blackbody at 2000 ?C, calculate the
energy absorbed in the glass and the energy transmitted.
18. Define Emissivity, Absorptivity, Reflectivity and Transmissivity and explain Wein's
displacement law.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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