An insulating material with a thermal conductivity k = 0.12W/mK is used for a pipe carrying steam. The local coefficient of heat transfer to the surrounding h = 4 W/m2K. In order to provide effective insulation, what should be the minimum outer diameter of the pipe?

An insulating material with a thermal conductivity k = 0.12W/mK is use

1.	An insulating material with a thermal conductivity k = 0.12W/mK is used for a pipe carrying steam. The local coefficient of heat transfer to the surrounding h = 4 W/m²K. In order to provide effective insulation, what should be the minimum outer diameter of the pipe?
A.	45mm
B.	60mm
C.	75mm
D.	90mm
Answer» C. 75mm

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An insulating material with a thermal conductivity k = 0.12W/mK is used for a pipe carrying steam. The local coefficient of heat transfer to the surrounding h = 4 W/m2K. In order to provide effective insulation, what should be the minimum outer diameter of the pipe?

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An insulating material with a thermal conductivity k = 0.12W/mK is used for a pipe carrying steam. The local coefficient of heat transfer to the surrounding h = 4 W/m²K. In order to provide effective insulation, what should be the minimum outer diameter of the pipe?