Chemical Engineering - Heat Transfer

36.
The value of Stefan-Boltazman constant in SI unit is
5.6697 x 10-8W/m2.°K4
0.1714 x 10-8W/m2.°K4
5.6697 x 10-8kcal/m2 . °K4
0.1714 x 10-8kcal/m2. °K4
Answer: Option
Explanation:
No answer description is available. Let's discuss.

37.
The unit of heat transfer co-efficient is
BTU/hr. ft2°F
BTU/hr. °F. ft.
BTU/hr. °F
BTU/hr. ft
Answer: Option
Explanation:
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38.
For turbulent flow in a tube, the heat transfer co-efficient is obtained from the Dittus-Boelter correlation. If the tube diameter is halved and the flow rate is doubled, then the heat transfer co-efficient will change by a factor of
1
1.74
6.1
37
Answer: Option
Explanation:
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39.
The inner wall of a furnace is at a temperature of 700°C. The composite wall is made of two substances, 10 and 20 cm thick with thermal conductivities of 0.05 and 0.1 W.m-1.°C-1 respectively. The ambient air is at 30°C and the heat transfer co-efficient between the outer surface of wall and air is 20 W.m-2.°C-1. The rate of heat loss from the outer surface in W.m-2is
165.4
167.5
172.5
175
Answer: Option
Explanation:
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40.
Value of Nusselt number [Nu = (hD/k)] for the heat transfer by conduction from a droplet or a spherical particle to a surrounding stagnant film is
0.5
2
10
100
Answer: Option
Explanation:
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