Latent Heat And Change Of State

According to NCERT Class 11, Chapter 11 (Thermal Properties of Matter), the heat supplied during a change of state does not raise the temperature but instead breaks the bonds holding the substance in its original phase; this energy is the latent heat, $Q=mL$. While a solid melts at its melting point, all the incoming heat goes into converting solid to liquid rather than increasing molecular kinetic energy, so the temperature stays fixed until melting is complete. The option claiming the temperature rises steadily ignores that energy is consumed by the phase change. The option that it falls is incorrect because heat is being added, not removed. The option of a rise-then-fall pattern has no basis during a single melting process. A consistency check is the familiar observation that an ice-water mixture remains at 0°C until all the ice melts, directly confirming that temperature stays constant throughout melting.