Download DBATU B.Tech 2019 March 3rd Semester Heat Transfer Operation Question Paper

Download DBATU (Dr. Babasaheb Ambedkar Technological University) B Tech 2019 March (Bachelor of Technology) 3rd Semester Heat Transfer Operation Question Paper

DR. BABASAHEB AMBEDKAR TECHNOLOGICAL UNIVERSITY, LONERE
Mid Semester Examination ? March 2019
Course: B. Tech in - Chemical Sem: III
Subj ect Name: Heat transfer Operation
Max Marks: 20 Date:- Duration:- 1 Hr.
Subject Code: BTCOC403
Instructions to the Students:
1. All questions are compulsory.
2. Question one are compulsory.
3. Solve any two from Question 2 and solve any one from question 3.
4. Assume suitable data wherever required.
Attempt following Questions.
(Level/CO)
Marks
1When vaporization takes place directly at the heating surface, it is called
a) ?lm boiling b) nucleate boiling c) vapor binding (1) None of these
2. Fourier's law applies to the heat transfer by
conduction. d) all (a), (b) & (c)
a) convection b) radiation c)
3.For an ideal black body
transmissivity = 1
a) absorptivity = 1 b) re?ectivity = 1 c) emissivity = 0 d)
4. The unit of heat transfer co-ef?cient in SI unit is -----------------
a) J/MZ?K b) W/m2?K c) W/m?K d) J/m?K
5. Which area is used in case of heat ?ow by conduction through a cylinder .a) Logarithmic
mean area b) Arithmetic mean area 0) Geometric mean area (1) None of these.
6. Which one gives the monochromatic emissive power for black body radiation ........... a)
Planck?s law b) Kirchhoffs law 0) Wien's law d) Stefan-Boltzman law
Q.2
Solve Any Two of the following.
3X2
(A)
Describe Film Boiling.
(B)
De?ne Emissivity, and Total emissive power.
(C)
Explain Boundary layer thickness and Displacement thickness.
Q.3
Solve Any One of the following.
(A)
Derive expression for temperature distribution through hollow Sphere.
(B)
Lubricating Oil at a temperature Of 60 ?C enters 1 cm diameter tube with a velocity of 3
m/s. Tube surface is maintained at 40 ?C. Assuming that the oil has the following average
properties calculate the tube length required to cool the oil to 45 ?C. Density = 865 Kg/m?, K =
0.14 W/m k Cl, = 1.78 KJ/Kg ?C. assume ?ow to be laminar (and fully developed ) Nu = 3.657
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