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-2 is
A. 165.4
B. 167.5
C. 172.5
D. 175
Answer: Option A
Related Questions on Heat Transfer
A. 3.06 × 105
B. 6.12 × 105
C. 7.24 × 105
D. 9.08 × 105
Fqra cold viscous feed, backward feed gives __________ than forward feed.
A. A higher capacity
B. A lower capacity
C. Lower economy
D. None of these
A. Twice
B. Four times
C. Square root of
D. Square of
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