Four rods of silver,copper,brass,and wood are of the same shape. They are heated together after wrapping a paper on each. The paper will burn first on:

Heat is flowing through a conductor of length $l$ from $x = 0$ to $x = l$. If its thermal resistance per unit length is uniform,which of the following graphs correctly represents the variation of temperature $T$ with distance $x$?

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 ......... $h$.

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

$A$ 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:

$A$ thin paper cup filled with water does not catch fire when placed over a flame. This is because