In the question number of `45`, the equivalent thermal conductivity of the compound bar isA. `(K_(1)K_(2))/(K_(1)+K_(2))`B. `(2K_(1)K_(2))/(K_(1)+K_(2))`C. `(K_(1))/(K_(1)+K_(2))`D. `(K_(2))/(K_(1)+K_(2))`

In the question number of `45`, the equivalent thermal conductivity of

1.	In the question number of `45`, the equivalent thermal conductivity of the compound bar isA. `(K_(1)K_(2))/(K_(1)+K_(2))`B. `(2K_(1)K_(2))/(K_(1)+K_(2))`C. `(K_(1))/(K_(1)+K_(2))`D. `(K_(2))/(K_(1)+K_(2))`
Answer» Correct Answer - B Let K be thermal conductivity of the temperature bar. Heat current through the compound bar of length `2L` is `H = (KA(T_(1) - T_(2)))/(2L)` At steady state, `H = H_(1) = H_(2)` `:. (KA(T_(1) - T_(2)))/(2L) = (K_(1)A(T_(1) - T_(0)))/(L) "â€¦..."(ii)` Substituting the value of `T_(0)` Eq (i) in (ii), we get `(K(T_(1)-T_(2)))/(2)= K_(1)[T_(1) - ((K_(1)T_(1) + K_(2)T_(2))/((K_(1)+K_(2))))] = (K_(1)K_(2)(T_(1)-T_(2)))/((K_(1)+K_(2)))` `rArr = (2K_(1)K_(2))/(K_(1)+K_(2))`

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In the question number of `45`, the equivalent thermal conductivity of the compound bar isA. `(K_(1)K_(2))/(K_(1)+K_(2))`B. `(2K_(1)K_(2))/(K_(1)+K_(2))`C. `(K_(1))/(K_(1)+K_(2))`D. `(K_(2))/(K_(1)+K_(2))`

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