A water-heater is covered up with insulation boards over a total surface area of 3 m2. The inside board surface is at 75¬¨¬®‚Äö√†√ªC and the outside surface is at 20¬¨¬®‚Äö√†√ªC and the board material has a conductivity of 0.08 W/m K. How thick a board should it be to limit the heat transfer loss to 200 W ?$#

A water-heater is covered up with insulation boards over a total surfa

1.	A water-heater is covered up with insulation boards over a total surface area of 3 m². The inside board surface is at 75¬¨¬®‚Äö√†√ªC and the outside surface is at 20¬¨¬®‚Äö√†√ªC and the board material has a conductivity of 0.08 W/m K. How thick a board should it be to limit the heat transfer loss to 200 W ?$#
A.	0.066 m
B.	0.166 m
C.	0.266 m
D.	0.366 m
Answer» B. 0.166 m

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