explain the 3 modes of heat transfer with example
Answers
Answer:
There are three modes of heat transfer: conduction, radiation, and convection. Conduction and radiation are fundamental physical mechanisms, while convection is really conduction as affected by fluid flow.Heat is a form of energy that can be transferred by three different modes from hot body to cold body or from higher to lower temperature. Total heat transfer is equal to the sum of heat transferred by all three modes of heat transfer: Conduction, Convection and Radiation.
Answer:
There are three modes of heat transfer.
Conduction
Convection
Radiation
1. Conduction of Heat
Heat conduction is a process in which heat is transferred from the hotter part to the colder part in a body without involving any actual movement of the molecules of the body. Heat transfer takes place from one molecule to another molecule as a result of the vibratory motion of the molecules. Heat transfer through the process of conduction occurs in substances which are in direct contact with each other. It generally takes place in solids.
Conduction example: When frying vegetables in a pan. Heat transfer takes place from flame to the pan and then to the vegetables.
Based on the conductivity of heat, substances can be classified as conductors and insulators. Substances that conduct heat easily are known as conductors and those that do not conduct heat are known as insulators.
2. Convection of Heat
In this process, heat is transferred in the liquid and gases from a region of higher temperature to a region of lower temperature. Convection heat transfer occurs partly due to the actual movement of molecules or due to the mass transfer.
For example. Heating of milk in a pan.
3. Radiation of Heat
It is the process in which heat is transferred from one body to another body without involving the molecules of the medium. Radiation heat transfer does not depend on the medium.
For example: In a microwave, the substances are heated directly without any heating medium