Convection in Liquids
In our home, we boil water to take a hot bath.
When we put water on the stove, the water will slowly get heated after a while.
We can see the water moving in circles.
The water is moving in circles because it is getting heated. This process of getting heated is called convection.
Those circles are called convection currents. Now let's learn about convection in liquids.
Convection in boiling water
Let's take a beaker of water and put it on the stove.
The bottom of the beaker gets heated slowly. The water near the flame gets heated first.
The heated water will move with higher speed and moves away from the flame.
So the hot water will rise up and reach the top.
Now the cold water in the beaker will be pushed by the hot water to the bottom of the beaker.
This cold water will be nearer to the flame so now it gets heated.
This will continuously happen and the water will get heated. That's why the water seems to be moving in circles.
In this way, the heat is transferred from the stove to water and water gets boiled.
This form of transfer of heat by an actual movement of liquid is called convection.
To get an even more clearer picture, add colour crystals to the water before heating.
Now let's put a candle at the bottom. This is how the heat current moves inside water.
Heat has a property of flowing from one place to another. One of the methods of transfer is convection.
In convection heat is transferred by the actual movement of the material. This happens in fluids like gases and liquids.