Properties Of Solids And Liquids Question 448
Question: A partition wall has two layers of different materials A and B in contact with each other. They have the same thickness but the thermal conductivity of layer A is twice that of layer B. At steady state the temperature difference across the layer B is 50 K, then the corresponding difference across the layer A is
Options:
A) 50 K
B) 12.5 K
C) 25 K
D) 60 K
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Let T be temperature of the junction Here, $ {{K} _{A}}=2K _{B}, $
$ T-T _{B}=50K $ At the steady state, $ H _{A}=H _{B} $
$ \therefore \frac{K _{A}A( T _{A}-T )}{L}=\frac{K _{B}A( T _{B}-T )}{L} $
$ 2K _{B}( T _{A}-T )=K _{B}( T-T _{B} ) $
$ T _{A}-T=\frac{T-T _{B}}{2}=\frac{50K}{2}=25K $
