A kettle is filled with tap water and placed on a stove. The stove element is turned on. Explain why the water starts to boil after a while. Solution Water boil due a mode of transfer of heat is called convection. Explanation- Convection is mode of transfer of heat from one region to another due to bulk movement of particles of medium under the temperature difference. when stove is tuned on, heat reach from flame of stove to the container of water due to radiation. Now, heat moves from outer surface of bottom of container to inner side ( water side) due to conduction process. Since, bottom of container has the higher temperature to top surface. So, bottom part of water gains heat due to which its density decreases slighly comparision to the upper part of the water, because of which, these two parts of water ( upper and top) gain some movement. Since, any material moves from higher density to lower density under the gravity. By this way, upper part of water ( which has higher density comparision to lower) moves downward and bottom part of water moves upward taking the heat energy with themselves. Thus, a cycle forms. Bottom part moves upward taking the heat energy and top part moves downward. This process continues further. By this way, water boil when stove is turned on. .

1. A kettle is filled with tap water and placed on a stove. The stove element is turned on. Explain
why the water starts to boil after a while.
Solution
Water boil due a mode of transfer of heat is called convection.
Explanation-
Convection is mode of transfer of heat from one region to another due to bulk movement of
particles of medium under the temperature difference.
when stove is tuned on, heat reach from flame of stove to the container of water due to radiation.
Now, heat moves from outer surface of bottom of container to inner side ( water side) due to
conduction process.
Since, bottom of container has the higher temperature to top surface. So, bottom part of water
gains heat due to which its density decreases slighly comparision to the upper part of the water,
because of which, these two parts of water ( upper and top) gain some movement. Since, any
material moves from higher density to lower density under the gravity. By this way, upper
part of water ( which has higher density comparision to lower) moves downward and bottom part
of water moves upward taking the heat energy with themselves.
Thus, a cycle forms. Bottom part moves upward taking the heat energy and top part moves
downward. This process continues further. By this way, water boil when stove is turned on.