A) \[\frac{({{r}_{2}}-{{r}_{1}})}{({{r}_{1}}{{r}_{2}})}\]
B) \[\ln \left( \frac{{{r}_{2}}}{{{r}_{1}}} \right)\]
C) \[\frac{{{r}_{1}}{{r}_{2}}}{({{r}_{2}}-{{r}_{1}})}\]
D) \[({{r}_{2}}-{{r}_{1}})\]
Correct Answer: C
Solution :
To measure the radial rate of heat flow, we have to go for integration technique as here the area of the surface through which heat will flow is not constant. Let us consider an element (spherical shell) of thickness ox and radius x as shown in figure. Let us first find the equivalent thermal resistance between inner and outer sphere. The thermal resistance of shell (from\[R=\frac{l}{KA},\]where K is thermal conductivity) The total thermal resistance, Now, rate of heat flowYou need to login to perform this action.
You will be redirected in
3 sec