Liquid oxygen at $50\ K$ is heated to $300\ K$ at a constant pressure of $1\ atm$. The rate of heating is constant. Which of the following graphs represents the variation of temperature with time?

$A$ solid material is supplied with heat at a constant rate. The temperature of the material changes with heat input as shown in the figure. What does the slope of $DE$ represent?

Liquid oxygen at $50\ K$ is heated to $300\ K$ at a constant pressure of $1\ atm$. The rate of heating is constant. Which of the following graphs represents the variation of temperature with time?

Explain the process of melting of ice with an explanation of freezing,melting,and melting point.

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 $H_A/H_B$?

Match the following according to conversion by heat:

Column-$I$	Column-$II$
$(a)$ Required heat to convert solid into gaseous.	$(i)$ Latent heat of fusion
$(b)$ Required heat to convert solid into liquid.	$(ii)$ Latent heat of vaporization