Two circular discs $A$ and $B$ with equal radii are blackend. They are heated to same temperature and are cooled under identical conditions. What inference do you draw from their cooling curves ?
$A$ and $B$ have same specific heats
Specific heat of $A$ is less
Specific heat of $B$ is less
Nothing can be said
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 rate of emission of radiation of a black body at $273^o C$ is $E$, then the rate of emission of radiation of this body at $0^o C$ will be
Six identical rods are arranged as shown in the figure. The temperature of the junction $B$ will be......... $^oC$
A cylinder of radius $R$ made of a material of thermal conductivity $K_1$ is surrounded by a cylindrical shell of inner radius $R$ and outer radius $2R$ made of material of thermal conductivity $K_2$ . The two ends of the combined system are maintained at two different temperatures. There is no loss of heat across the cylindrical surface and the system is in steady state. The effective thermal conductivity of the system 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 ........ $^oC$