When two bodies at different temperatures are in thermal contact with each other, thermal energy from a hot body flows to a cold body in the form of heat. This is called heat transfer.
Transfer of heat is a natural process. It continues all the time as long as the bodies in thermal contact are at different temperatures. There are three types of heat transfer. These are given below in the list:
What is Conduction Of Heat?
Conduction is the process in which heat transfers due to the direct contact of molecules. It can occur in solids, liquids, and gasses. Conduction occurs due to free electrons.
What is Convection of Heat?
Convection is the process in which heat transfer due to up and down movement of molecules or due to actual movement of molecules. Convection occurs only in liquids and Gasses. A convection current is an example of heat transfer.
What is Radiation of Heat?
Radiation is the mode of heat transfer in which heat is transferred through open space. It occurs only in Gases.
Watch video about heat transfer methods:
Applications of Conduction of Heat:
Conduction plays an important role in our daily lives:
- Cooking utensils, electric kettles, irons, soldering irons, etc. are made of metals to conduct heat quickly. their handles are made of plastic or wood which are bad conductors.
- Birds have feathers that keep their bodies warm because feathers are a bad conductor of heat.
- woolen clothes and blankets slow down the transfer of heat. It happens so because the wool traps air in it. The air is a bad conductor of heat.
- Ice is covered with jute rugs to reduce its melting speed.
- jute is the bad conductor of heat.
- An insulating material (e.g. Styrofoam) is filled between the double walls of a refrigerator.it reduces the transfer of heat across the walls of the refrigerator.
- Double plane windows are used in buildings to slow the transfer of heat. The air between the two layers of glass acts as an insulator.
- Thermos bottles use air or a vacuum to slow the transfer of heat by conduction.
How many Types by which heat transfer?
There are three ways by which heat can flow, which are given in the list below: