Conduction transfers heat via direct molecular collision. An area of larger mechanical energy can transfer thermal energy to a region with lower mechanical energy. Higher-speed particles will collide with slower speed particles. The slower-speed particles can increase in mechanical energy as a result. Conduction is that the most typical sort of heat transfer and happens via physical contact Example: A cooking pan on flame or oven gets heated due to conduction (Fig 2).
When a fluid, such as air or a liquid, is heated and then it travels away from the source, it carries the thermal energy along. This type of heat transfer is called convection. The fluid on top of a hot surface expands, becomes less dense, and rises.
Both conductivity and convection need a medium for the transfer of the heat. Radiation could be a methodology of heat transfer that doesn't rely on any contact between the warmth supply and therefore the heated object. For example, we have a tendency to feel the heat from the sun even if we have a tendency to aren't touching it. Heat may be transmitted through an empty area by thermal radiation. Thermal radiation (often referred to as infrared radiation) could be a kind nonparticulate radiation (or light). Radiation could be a variety of energy transport consisting of magnetism waves traveling at the speed of sunshine. No mass is changed and no medium is needed. Ultraviolet rays reach the planet by means of radiation. (Fig 4)
|BASIS FOR COMPARISON||CONDUCTION||CONVECTION||RADIATION|
|Basic definition||Conduction is a procedure by means of which heat transfer occurs between objects that are in direct contact.||Convection can be defined as the form of heat transfer where energy is transferred within liquid or gas.||Radiation involves the mechanism where heat is transmitted between objects that are devoid of any physical contact.|
|Representation||How heat traverses between the bodies in direct contact.||How heat gets diffused through fluids.||How heat passes through the vacuum.|
|Cause of occurrence||The temperature difference or the difference in kinetic energy results conduction.||The difference in density of the fluid results in convection.||Any object at a temperature greater than 0K can radiate.|
|Medium of Occurrence||Takes place preferably in solids, due to molecular collisions.||The actual flow of matter in fluid results in convection.||Without heating the intervening surface, it heats the medium at a distance.|
|Transfer of heat||Heated solid bodies||Through intermediate substance.||In the form of electromagnetic waves.|