The wavelength of maximum energy released during an atomic explosion was $2.93\times10^{-10}\, m$. The maximum temperature attained must be, (Weins constant $= 2.93\times10^{-3}\, mK$)
$5.86\times10^7\, K$
$10^{-13}\, K$
$10^{-7}\, K$
$10^7\, K$
A cylindrical metallic rod in thermal contact with two reservoirs of heat at its two ends conducts an amount of heat $Q$ in time $t$. The metallic rod is melted and the material is formed into a rod of half the radius of the original rod. What is the amount of heat conducted by the new rod, when placed in thermal contact with same two reservoirs in time $t$
A black body is heated from $7\,^oC$ to $287\,^oC$. The ratio of radiation emitted is
Three very large plates of same area are kept parallel and close to each other. They are considered as ideal black surfaces and have very high thermal conductivity. The first and third plates are maintained at temperatures $2\,T$ and $3\,T$ respectively. The temperature of the middle (i.e. second) plate under steady state condition is
In a composite rod, when two rods of different lengths and of the same area are joined end to end, then if $K$ is the effective coefficient of thermal conductivity ; $\frac{{{\ell _1} + {\ell _2}}}{K}$ is equal to
Six identical rods are arranged as shown in the figure. The temperature of the junction $B$ will be......... $^oC$