What do you understand by thermal conductivity?

Answer 1

Thermal conductivity is more relevant to solids. Liquids and gases transfer heat using a process known as convection. There is also radiation mode of heat trasfer. Conduction is the process by which the molecules of the metal transfer heat from one to the other without the molecules themselves moving. For example if one end of a metal rod is heated and you hold the other end, pretty soon you will not be able to hold on to the rod. This is because heat from the hot end is transferred from one molecule to the next (without the molecules themselves moving) since heat wants to move from a hotter reagion to a a colder region of the rod. Different substances have different capacity to transfer heat along its length. Copper is a good conductor of heat. Wood and synthetic plastic materials are poor conductors of heat. That's why frying pans and cooking pots have non-metallic handles so that dear mom can handle them with ease and comfort. Each material transfers heat inversely proportional to its length and directly proportional to its cross-sectional area. That means that a longer rod will mean that it will take longer for the heat to reach the colder end. Similarly, if the cross-sectional area is large, heat will be transferred faster to the other end. Each material has a "coefficient of thermal conductivity".

Answer 2

Thermal conductivity is a material property that describes how well a material can conduct heat. It measures the rate at which heat is transferred through a material when there is a temperature difference across it. Materials with high thermal conductivity can transfer heat quickly, while those with low thermal conductivity transfer heat more slowly.