A slab consists of two parallel layers of two different materials of same thickness having thermal conductivities $K_1$ and $K_2$ . The equivalent conductivity of the combination is
Medium
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(b) In parallel combination equivalent conductivity
$K = \frac{{{K_1}{A_1} + {K_2}{A_2}}}{{{A_1} + {A_2}}} = \frac{{{K_1} + {K_2}}}{2}$ (As ${A_1} = {A_2}$)
$K = \frac{{{K_1}{A_1} + {K_2}{A_2}}}{{{A_1} + {A_2}}} = \frac{{{K_1} + {K_2}}}{2}$ (As ${A_1} = {A_2}$)
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