End $A$ of a copper rod is maintained in steam. Chamber $(100\,^oC)$ and other end $B$ is maintained at $0\,^oC$ . Assume $x = 0$ at $A,$ the $T-x$ graph will be (in steady state)

Three copper blocks of masses $M_1, M_2$ and $M_3$ $kg$ respectively are brought into thermal contact till they reach equilibrium. Before contact, they were at $T_1, T_2, T_3(T_1> T_3)$. Assuming there is no heat loss to the surroundings, the equilibrium temprature $T$ is ($s$ is specific heat of copper)

The surface temperature of the sun which has maximum energy emission at $500\, nm$ is $6000\, K$. The temperature of a star which has maximum energy emission at $400\, nm$ will be ........ $K$

If the wavelengths of maximum intensity of radiations emitted by the sun and the moon are $0.5\times10^{-6}\, m$ and $10^{-4}\,m$ respectively. The ratio of their temperatures is

Six identical conducting rods are joined as shown in figure. Points $A$ and $D$ are maintained at temperatures $200\,^oC$ and $20\,^oC$, respectively. the temperature of junction $B$ will be......... $^oC$

Two rods $A$ and $B$ of same cross-sectional are $A$ and length $l$ connected in series between a source $(T_1 = 100^o C)$ and a sink $(T_2 = 0^o C)$ as shown in figure. The rod is laterally insulated The ratio of the thermal resistance of the rod is