Question 79: Thermodynamics & KTG

Question

Consider a compound slab consisting of two different materials having equal lengths, thickness and thermal conductivities K and 2K respectively. The equivalent thermal conductivity of the slab is

Accepted Answer

Equivalent thermal conductivity of the compound slab,
${K_{eq}} = {{{l_1} + {l_2}} \over {{{{l_1}} \over {{K_1}}} + {{{l_2}} \over {{K_2}}}}} = {{l + 1} \over {{l \over K} + {l \over {2K}}}} = {{2l} \over {{{3l} \over {2K}}}} = {{4K} \over 3}$

Answer

$\sqrt2$K

Answer

$3$K

Answer

$\frac{4}{3}$K

Answer

$\frac{2}{3}$K

Thermodynamics & KTG

Consider a compound slab consisting of two different materials having equal lengths, thickness and thermal conductivities K and 2K respectively. The equivalent thermal conductivity of the slab is

Choose the correct answer: