An ice cube at temperature $-20^oC$ is kept in a room at temperature $20^oC$. The variation of temperature of the body with time is given by

$Assertion :$ 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.

$A$ 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 $g$)

$A$ block of ice at $-10^{\circ}C$ is slowly heated and converted to steam at $100^{\circ}C$. Which of the following curves represents the phenomenon qualitatively?

Explain the process of change in the state of matter by heating or cooling it.

$A$ metallic ball and a highly stretched spring are made of the same material and have the same mass. They are heated so that they melt. The latent heat required: