The graph signifies:

$A$ substance of mass $m \ kg$ requires a power input of $P \ W$ to remain in the molten state at its melting point. When the power is turned off,the sample completely solidifies in time $t \ s$. What is the latent heat of fusion of the substance?

What are fusion and melting point? On what does the value of melting point depend?

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?

Why do we get burnt more by steam than by boiling water at the same temperature?

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