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General
Easy
Question
A wall is made up of two layers A and B. The thickness of the two layers is the same, but materials are different. The thermal conductivity of A is double than that of B. In thermal equilibrium the temperature difference between the two ends is 
. Then the difference of temperature at the two surfaces of A will be
The correct answer is:
Suppose thickness of each wall is x then 
Þ 
and 
Þ 
Hence temperature difference across wall A is
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