Compared to a burn due to water at $100^{\circ}C$,a burn due to steam at $100^{\circ}C$ is

$A$ solution consists of ether and $5.0 \ g$ of water at $0^{\circ} C$. If the ether evaporates completely to freeze the water, then the mass of the ether in the solution is (in $g$)

Boiling water is changing into steam. At this stage,the specific heat of water is

The graph signifies:

Match the following items in Column-$I$ with their corresponding definitions in Column-$II$.

Column-$I$	Column-$II$
$A$. Conversion of liquid into solid is	$1$. Regelation
$B$. Conversion of liquid into vapour is	$2$. Sublimation
$C$. Conversion of solid into vapour directly is	$3$. Fusion
$D$. Melting of ice caused by pressure is	$4$. Vaporisation

Two substances $A$ and $B$ of equal mass are heated at a constant rate of $6 \ cal \ s^{-1}$. The graph shows the temperature versus time. What is the ratio of the heat absorbed for complete melting $H_A/H_B$?