Theory:

When we drink hot tea or coffee in a cup, the cup shows some hotness because of the hot tea or coffee.
 
When we apply heat to a pan, the pan becomes hot. But, after a couple of minutes, the hot pan loses its heat and returns to average room temperature.
 
Do you know why does this happen?
 
Because the tea transfers its heat to the surroundings, and returns to the average room temperature.
 
tea-1105113_1280.jpg
Fig. - Example for heat transfer
 
These two examples show that heat transfer occurs from the hotter region to the colder region.
 
We understand that the heat flows from the hotter region (object) to the colder region (object), but how it is transferring?
 
Knowing that heat is a form of energy that flows from one place to another in three different ways.
 
That is,
 
1. Conduction
2. Convection and
3. Radiation
  
In upcoming lessons, we will discuss these methods in detail with the help of examples.