$A$ quantity of heat required to change the unit mass of a solid substance,from solid state to liquid state,while the temperature remains constant,is known as

During an experiment,it takes $10 \text{ minutes}$ to raise the temperature of water from $0 \text{ °C}$ to $100 \text{ °C}$,and then it takes another $55 \text{ minutes}$ for the water to completely convert into steam. The value of the latent heat of vaporization is ....... $\text{cal/g}$.

$Assertion :$ Melting of a solid causes no change in internal energy.
$Reason :$ Latent heat is the heat required to melt a unit mass of a solid.

$A$ solid substance is at $30^{\circ}C$. To this substance,heat energy is supplied at a constant rate. The temperature versus time graph is as shown in the figure. The substance is in the liquid state for the portion of the graph:

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

What is latent heat? Explain with an example.