Question

GIVE REASON:-

Thermameter reading remains constant for a while during melting of a solid even though we continue bot not liquids.why????

Answer 1

this is due to laten heat.....

Answer 2

Melting of solid is change in its phase from solid to liquid phase. Supplied heat gets utilised to break bonds and change its phase therefore you'll observe no change on thermometer.
Heating water leads to rise in thermometer readings because energy supplied to it is not utilised to change its phase from loquid to gas or steam