The length of the two rods made up of the same metal and having the same area of cross-section are $0.6 m$ and $0.8 m$ respectively. The temperature between the ends of first rod is ${90^o}C$ and ${60^o}C$ and that for the other rod is $150^oC$ and ${110^o}C$. For which rod the rate of conduction will be greater
First
Second
Same for both
None of the above
Two metal cubes $A$ and $B$ of same size are arranged as shown in the figure. The extreme ends of the combination are maintained at the indicated temperatures. The arrangement is thermally insulated. The coefficients of thermal conductivity of $A$ and $B$ are $300\;W/m{\;^o}C$ and $200\;W/m{\;^o}C$, respectively. After steady state is reached, the temperature of the interface will be...... $^oC$
Consider a compound slab consisting of two different materials having equal thickness and thermal conductivities $ K$ and $2K$ respectively. The equivalent thermal conductivity of the slab is
When two ends of a rod wrapped with cotton are maintained at different temperatures and after some time every point of the rod attains a constant temperature, then
Three rods of same material, same area of crosssection but different lengths $10 \,cm , 20 \,cm$ and $30 \,cm$ are connected at a point as shown. What is temperature of junction $O$ is ......... $^{\circ} C$
Three identical rods $AB$, $CD$ and $PQ$ are joined as shown. $P$ and $Q$ are mid points of $AB$ and $CD$ respectively. Ends $A, B, C$ and $D$ are maintained at $0^o C, 100^o C, 30^o C$ and $60^o C$ respectively. The direction of heat flow in $PQ$ is