Thermal Properties of Matter - Result Question 36

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37. Two rods of thermal conductivities $K_1$ and $K_2$, crosssections $A_1$ and $A_2$ and specific heats $S_1$ and $S_2$ are of equal lengths. The temperatures of two ends of each rod are $T_1$ and $T_2$. The rate of flow of heat at the steady state will be equal if/2002]

======= ####37. Two rods of thermal conductivities $K_1$ and $K_2$, crosssections $A_1$ and $A_2$ and specific heats $S_1$ and $S_2$ are of equal lengths. The temperatures of two ends of each rod are $T_1$ and $T_2$. The rate of flow of heat at the steady state will be equal if/2002]

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/thermal-properties-of-matter/thermal-properties-of-matter—result-question-36.md (a) $\frac{K_1}{A_1 S_1}=\frac{K_2}{A_2 S_2}$

(b) $K_1 A_1=K_2 A_2$

(c) $K_1 S_1=K_2 S_2$

(d) $A_1 S_1=A_2 S_2$

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Answer:

Correct Answer: 37. (b)

Solution:

  1. (b) Rate of heat flow for one rod

$=\frac{K_1 A_1(T_1-T_2)}{d}(d \to$ Length $)$

Rate of heat flow for other rod

$=\frac{K_2 A_2(T_1-T_2)}{d}$

In steady state, $\frac{K_1 A_1(T_1-T_2)}{d}$

$=\frac{K_2 A_2(T_1-T_2)}{d} \Rightarrow K_1 A_1=K_2 A_2$