A) \[{{K}_{1}}+{{K}_{2}}\]
B) \[{{K}_{1}}{{K}_{2}}/({{K}_{1}}+{{K}_{2}})\]
C) \[({{K}_{1}}+3{{K}_{2}})/4\]
D) \[(3{{K}_{1}}+{{K}_{2}})/4\]
Correct Answer: C
Solution :
Heat flowing per sec. through cylinder of radius R, \[{{Q}_{1}}={{K}_{1}}(\pi {{R}^{2}})\left( \frac{{{T}_{1}}-{{T}_{2}}}{l} \right)\] Heat flowing per sec through outer shell of radius 2R, \[{{Q}_{2}}={{K}_{1}}(\pi {{(2R)}^{2}}-\pi {{R}^{2}})\left( \frac{{{T}_{1}}-{{T}_{2}}}{l} \right)\] Total \[Q={{Q}_{1}}+{{Q}_{2}}=({{K}_{1}}+3{{K}_{2}})\pi {{R}^{2}}\left( \frac{{{T}_{1}}-{{T}_{2}}}{l} \right)\] ?.(1)You need to login to perform this action.
You will be redirected in
3 sec