Q1 of 41 Page 46

Is heat a conserved quantity?

No, heat is not a conserved quantity.


A conserved quantity remains the same before and after the physical event.


Heat is a form of energy, and energy can neither be created nor be destroyed, but can transform from one form to another.


Best example is a thermocouple, where heat energy is transformed into electrical output due to adjoining two dissimilar metals.


From 1st principle of thermodynamics, only the total energy before or after transformation remains constant.


More from this chapter

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2

The calorie is defined as 1 cal = 4.186 joule. Why not as 1 cal = 4J to make the conversions easy?

 3

A calorimeter is kept in a wooden box to insulate it thermally from the surroundings. Why is it necessary?

 4

In a calorimeter, the heat given by the hot object is assumed to be equal to the heat taken by the cold object. Does it mean that heat of the two objects taken together remains constant?

 5

In Regnault’s apparatus for measuring specific heat capacity of a solid, there is an inlet and an outlet in the steam chamber. The inlet is near the top and the outlet is near the bottom. Why is it better than the opposite choice where the inlet is near the bottom and the outlet is near the top?