Two rods `A` and `B` of different materials are welded together as shown in figure. Their thermal conductivities are `K_(1)` and `K_(2)`. The thermal conductivity of the composite rod will be A. `(3 (K_(1) + K_(2)))/(2)`B. `K_(1) + K_(2)`C. `2 (K_(1) + K_(2))`D. `(K_(1) + K_(2))/(2)`

Two rods `A` and `B` of different materials are welded together as sho

1.	Two rods `A` and `B` of different materials are welded together as shown in figure. Their thermal conductivities are `K_(1)` and `K_(2)`. The thermal conductivity of the composite rod will be A. `(3 (K_(1) + K_(2)))/(2)`B. `K_(1) + K_(2)`C. `2 (K_(1) + K_(2))`D. `(K_(1) + K_(2))/(2)`
Answer» Correct Answer - D In parallel `(1)/(R_(eq)) = (1)/(R_1) +(1)/(R_2)` `(K_(eq)(2A))/(l) = (k_(l)A)/(l)+(K_(2)A)/(l)` `K_(eq) = (K_(1)+K_(2))/(2)`.

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Two rods `A` and `B` of different materials are welded together as shown in figure. Their thermal conductivities are `K_(1)` and `K_(2)`. The thermal conductivity of the composite rod will be A. `(3 (K_(1) + K_(2)))/(2)`B. `K_(1) + K_(2)`C. `2 (K_(1) + K_(2))`D. `(K_(1) + K_(2))/(2)`

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