The critical radius of insulation for a spherical shell is (where, K = – McqOptions

MCQOPTIONS

1.	The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h₀ = heat transfer coefficient at the outer surface)
A.	K/h₀
B.	2K/h₀
C.	h₀/K
D.	h₀/2K
Answer» C. h₀/K

Discussion

No Comment Found

Related MCQs

When does the heat generated by fluid friction becomes appreciable compared to the heattransferred between the fluids?
For heat flow through very thick walled cylinder, use _________mean radius.
Heat conducted througfi unit area and unit thick face per unit time whentemperature difference between opposite faces is unity,is called
Two plates spaced 150 mm apart are maintained at 1000°C and 70°C. The heattransfer will take place mainly by
According to Kirchoff’s law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a
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.°C1 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
Intermittent tube cleaning is possible to be done in case of a __________ evaporator.
The maximum heat transfer co-efficient from steam heating will be attained when thesteam is:
The average heat transfer co-efficient over the entire length of the plate (ha) and the localheat transfer co-efficient (hL), in case of heat transfer over a flat plate in laminar zone is related as
The heat transfer by radiation from a mild steel surface is to be reduced by reducing theemissivity of the surface. This can be best achieved by