Three rods of equal length and cross sectional area and coefficient of thermal conductivities $K, 2K$ and $3K$ are joined as shown in figure temperature of their ends are $110\ ^oC, 20\ ^oC$ and $0\ ^oC$ respectively then temperature of junction will be ......... $^oC$

Which of the following circular rods. (given radius $ r$ and length $l$ ) each made of the same material as whose ends are maintained at the same temperature will conduct most heat

A piece of glass is heated to a high temperature and then allowed to cool. If it cracks, a probable reason for this is the following property of glass

A slab consists of two parallel layers of two different materials of same thickness having thermal conductivities $K_1$ and $K_2$ . The equivalent conductivity of the combination is

The thickness of a metallic plate is $0.4 cm$ . The temperature between its two surfaces is ${20^o}C$. The quantity of heat flowing per second is $50$ calories from $5c{m^2}$ area. In $CGS$ system, the coefficient of thermal conductivity will be

What is the temperature (in $^oC$) of the steel-copper junction in the steady state of the system shown in Figure Length of the steel rod $=15.0\; cm ,$ length of the copper rod $=10.0\; cm ,$ temperature of the furnace $=300^{\circ} C ,$ temperature of the other end $=0^{\circ} C .$ The area of cross section of the steel rod is twice that of the copper rod. (Thermal conductivity of steel $=50.2 \;J s ^{-1} m ^{-1} K ^{-1} ;$ and of copper $\left.=385 \;J s ^{-1} m ^{-1} K ^{-1}\right)$