The distribution of relative intensity $I(\lambda )$ of blackbody radiation from a solid object versus the wavelength $\lambda $ is shown in the figure . If the Wien displacement law Constant is $2.9 \times 10^{-3}\ mK$ , what is the approximate temperature of the object ........ $K$.

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 ends of roads of length $L$ and radius $r$ of the same material are kept at the same temperature which of the following rod conducts most heat?

$Assertion :$ Bodies radiate heat at all temperatures.
$Reason :$ Rate of radiation of heat is proportional to the fourth power of absolute temperature.

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 metal wires of identical dimensions are connected in series. If $\sigma _1$ and $\sigma _2$ are the conductivities of the metal wires respectively, the effective conductivity of the combination is