Question 331: Thermodynamics & KTG

Question

Two identical metal wires of thermal conductivities K
1
and K
2
respectively are connected in series. The effective thermal conductivity of the combination is :

Accepted Answer

$${R_{eq}} = {R_1} + {R_2}$$
$$ \Rightarrow $$ $${1 \over {{K_{eq}}}}{{2l} \over A} = {l \over {{K_1}A}} + {l \over {{K_2}A}}$$
$$ \Rightarrow $$ $${2 \over {{K_{eq}}}} = {l \over {{K_1}}} + {l \over {{K_2}}}$$
$$ \Rightarrow $$ $${2 \over {{K_{eq}}}} = {{{K_1} + {K_2}} \over {{K_1}{K_2}}}$$
$$ \Rightarrow $$ $${K_{eq}} = {{2{K_1}{K_2}} \over {{K_1} + {K_2}}}$$

Answer

$${{2{K_1}{K_2}} \over {{K_1} + {K_2}}}$$

Answer

$${{{K_1} + {K_2}} \over {{K_1}{K_2}}}$$

Answer

$${{{K_1} + {K_2}} \over {2{K_1}{K_2}}}$$

Answer

$${{{K_1}{K_2}} \over {{K_1} + {K_2}}}$$

Thermodynamics & KTG

Two identical metal wires of thermal conductivities K 1 and K 2 respectively are connected in series. The effective thermal conductivity of the combination is :

Choose the correct answer: