A composite block is made of slabs $A, B, C, D$ and $E$ of different thermal conductivities (given in terms of a constant $K$ ) and sizes (given in terms of length, $L$ ) as shown in the figure. All slabs are of same width. Heat $'Q'$ flows only from left to right through the blocks. Then in steady state $Image$

$(A)$ heat flow through $A$ and $E$ slabs are same.

$(B)$ heat flow through slab $E$ is maximum.

$(C)$ temperature difference across slab $E$ is smallest.

$(D)$ heat flow through $C =$ heat flow through $B +$ heat flow through $D$.

The two opposite faces of a cubical piece of iron (thermal conductivity $= 0.2\, CGS$ units) are at ${100^o}C$ and ${0^o}C$ in ice. If the area of a surface is $4c{m^2}$, then the mass of ice melted in $10$ minutes will be …… $gm$

On which factor does the thermal conductivity depend ?

Four rods of same material and having the same cross section and length have been joined, as shown. The temperature of junction of four rods will be…….. $^oC$

A rod of length $L$ with sides fully insulated is of a material whose thermal conductivity varies with $\alpha$ temperature as $ K= \frac{\alpha }{T}$, where $\alpha$ is a constant. The ends of the rod are kept at temperature $T_1$ and $T_2$. The temperature $T$ at $x,$ where $x$ is the distance from the end whose temperature is $T_1$ is