question_answer

If a piece of metal is heated to temperature\[\theta\] and then allowed to cool in a room which is at temperature \[{{\theta }_{0}},\]  the graph between the temperature T of the metal and time t will be closed to:                            [JEE MAIN 2013]

A)          

B)

C)  

D)       

Correct Answer: C

Solution :

[c] Since, by Newton’s law of cooling, the rate of change of temperature is proportional to the difference in temperature between the object and surrounding, as the temperature of the piece of metal approachesthe rate of change of temperature will approach zero.