Physics

Problem

Three slabs, each of thickness

d

, are placed in series. Their thermal conductivities are

0.5\,\text{W m}^{-1}\text{K}^{-1}

1.0\,\text{W m}^{-1}\text{K}^{-1}

and

2.0\,\text{W m}^{-1}\text{K}^{-1}

respectively. What is the equivalent thermal conductivity

k_{\text{eq}}

of the combination? a)

1.17\,\text{W m}^{-1}\text{K}^{-1}

0.86\,\text{W m}^{-1}\text{K}^{-1}

1.0\,\text{W m}^{-1}\text{K}^{-1}

0.29\,\text{W m}^{-1}\text{K}^{-1}