Q. A substance of mass M kg rquires a power input of P watts
to remain in the molten state at its melting point . When the
power source is turned off, the sample completely solidifes
in time t second .the latent heat of fusion of the substance is
.................

 1724  201 IIT JEEIIT JEE 1992Thermodynamics Report Error

Solution:

Heat lost in time t = Pt = ML