$2\;gm$ of steam condenses when passed through $40gm$ of water initially at $25^oC.$ The condensation of steam raises the temperature of water to $54.3^oC.$ What is the latent heat of steam ........... $cal/g$
$540$
$536$
$270$
$480$
What is vapourization ? What is normal boiling point ?
A child running a temperature of $101\,^{\circ} F$ is given an antipyrin (i.e. a medicine that lowers fever) which causes an increase in the rate of evaporation of sweat from his body. If the fever is brought down to $98\,^{\circ} F$ in $20$ minutes, what is the average rate of extra evaporation caused, by the drug (in $g/min$). Assume the evaporation mechanism to be the only way by which heat is lost. The mass of the child is $30\; kg$. The spectfic heat of human body is approximately the same as that of water, and latent heat of evaporation of water at that temperature is about $580\; cal \;g^{-1}$.
The graph shows the variation of temperature $(T)$ of one kilogram of a material with the heat $(H)$ supplied to it. At $O,$ the substance is in the solid state. From the graph, we can conclude that
An ice cube at temperature $-20^o C$ is kept in a room at temperature $20^o C$. The variation of temperature of the body with time is given by
A block of ice at $-12^{\circ} C$ is slowly heated and converted into steam at $100^{\circ} C$. Which of the following curves best represents the event?