The quantity of heat which crosses unit area of a metal plate during conduction depends upon

The radius of a conductor increases uniformly from the left end to the right end as shown in the figure. The material of the conductor is isotropic,and its curved surface is thermally isolated from the surroundings. Its ends are maintained at temperatures $T_1$ and $T_2$ $(T_1 > T_2)$. If,in a steady state,the heat flow rate is equal to $H$,then which of the following graphs is correct?

In a steady state,the temperature at the end $A$ and end $B$ of a $20 \ cm$ long rod $AB$ are $100^{\circ} C$ and $0^{\circ} C$. The temperature of a point,$9 \ cm$ from $A$ is (in $^{\circ} C$)

The bottom of a lake is at $0^{\circ} C$ and the atmospheric temperature is $-20^{\circ} C$. If $1 \, cm$ of ice is formed on the surface in $24 \, h$,then the time taken to form the next $1 \, cm$ of ice is ......... $h$.

In the steady state,the temperature of a body ...

The temperature gradient in a rod of length $75 \ cm$ is $40^{\circ} C/m$. If the temperature of the cooler end of the rod is $10^{\circ} C$,then the temperature of the hotter end is: (in $^{\circ} C$)