A) 1 :1
B) 4 : 3
C) 8 : 9
D) 3 : 2
Correct Answer: C
Solution :
For cylindrical rod \[A=\pi {{r}^{2}}\] \[\therefore \] Amount of heat flowing per second \[H=\frac{Q}{t}=\frac{KA\Delta \theta }{d}=\frac{K\pi {{r}^{2}}\Delta \theta }{d}\] or \[H\propto \frac{{{r}^{2}}}{d}\] So, \[\frac{{{H}_{1}}}{{{H}_{2}}}={{\left( \frac{{{r}_{1}}}{{{r}_{2}}} \right)}^{2}}.\frac{{{d}_{2}}}{{{d}_{1}}}\] \[={{\left( \frac{2}{3} \right)}^{2}}.\frac{2}{1}=\frac{8}{9}\]You need to login to perform this action.
You will be redirected in
3 sec