Difference between Conduction and Convection
|It is the transmission of heat from one part of the body to another part by the interaction of electrons and molecules.||It is the transmission of heat due to the actual movement of molecules of the substance from one place to the other.|
|It occurs in solids.||It occurs in liquids and gases.|
Change in position of molecules
|During conduction, molecules do not change their average position.||During convection, molecules change their position.|
Conduction is the process in which heat is transferred from one part of the body to (lie other by the interaction of electrons and molecules.
- When a body is heated its temperature rises at the heating place. Due to the rise in the average kinetic energy of atoms increases.
- Hence the atoms begin to vibrate with greater and greater amplitude with the rise of temperature about their mean positions
- This results in the collision of atoms.
- The heat absorbed by an atom is transferred to the neighboring atoms through collision
- A long metal bar is covered with a thin layer of wax at one end.
- The wax-coated end is heated by placing it under a thin layer of wax at one end.
- The wax Coated end is heated by placing it under a flame. This end absorbs heat energy and as a result, wax begins to melt.
- As time passes on. The melting starting at the hot end goes further and further along with the wax-coated length of the rod.
Convection is the transmission of heat due to the actual movement of molecules of the substance from one place to the other.
The fluid receives heat directly from the source and gets heated. It expands. Become lighter and therefore rises up. The circulation of fluid sets up a convection current.
The same process holds in the boiling of water which is taken ¡n electric kettle. The heater of the kettle is normally placed near the bottom of the kettle so that as the water lying at the bottom of the kettle is heated, it expands and gets lighter. Being lighter, It rises up the cooler section of water being denser moves down and heated. This process is repeated due to convection set up until the whole water reaches the boiling point.