A) 2/9
B) 9/2
C) 2/7
D) 7/2
Correct Answer: C
Solution :
Since there is no flow of heat in rod, so temperature of B is equal to temperature at A i.e., \[{{\theta }_{B}}={{\theta }_{A}}=20{{\,}^{o}}C\] Heat flowing through DB per second = heat flowing through BC per second i.e., \[\frac{KA({{90}^{o}}-{{20}^{o}})}{{{l}_{BD}}}=\frac{KA({{20}^{o}}-{{0}^{o}})}{{{l}_{BC}}}\] \[\therefore \] \[\frac{{{l}_{BC}}}{{{l}_{BD}}}=\frac{2}{7}\]You need to login to perform this action.
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