A wall has two layers $A$ and $B,$ each made of different material. Both the layers have the same thickness. The thermal conductivity for $A$ is twice that of $B$ and under steady condition, the temperature difference across the wall is $36\,^oC.$ The temperature difference across the layer $A$ is....... $^oC$

The wavelength of maximum energy released during an atomic explosion was $2.93\times10^{-10}\, m$. The maximum temperature attained must be, (Weins constant $= 2.93\times10^{-3}\, mK$)

Two rods $A$ and $B$ of different materials but same cross section are joined as in figure. The free end of $A$ is maintained at $100^o C$ and the free end of $B$ is maintained at $0^o C$. If $l_2 = 2l_1, K_1 = 2K_2$ and rods are thermally insulated from sides to prevent heat losses then the temperature $\theta$ of the junction of the two rods is ........ $^oC$

The plots of intensity versus wavelength for three black bodies at temperature $T_1$, $T_2$ and $T_3$ respectively are as shown. Their temperatures are such that

Two plates of same thickness of coefficients of thermal conductivities $K_1$ and $K_2$ and areas of cross section $A_1$ and $A_2$ are connected as shown. The effective coefficient of thermal conductivity $K$.

The heat is flowing through two cylindrical rods of same material. The diameters of the rods are in the ratio $1 : 2$ and their lengths are in the ratio $2 : 1$. If the temperature difference between their ends is the same, the ratio of rates of flow of heat through them will be