Ice is used in a cooler in order to cool its contents. Which of the following will speed up the cooling process?

$Assertion :$ Woolen clothes keep the body warm in winter.
$Reason :$ Air is a bad conductor of heat.

The difference of temperature in a material can convert heat energy into electrical energy. To harvest the heat energy,the material should have

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?

The value of the temperature gradient is $80\,^{\circ}C/m$ on a rod of $0.5\,m$ length. If the temperature of the hot end is $30\,^{\circ}C$, what is the temperature of the cold end?

If it takes $7 \, h$ to form a $1 \, cm$ thick layer of ice on a pond at $0^o C$,how many hours will it take for the thickness of the ice layer to increase from $1 \, cm$ to $2 \, cm$?