Thermal conductivity is defined as the heat flow per unit time
Thermal conductivity of a material is because of migration of free electrons and lattice vibrational waves.
Mark the matter with least value of thermal conductivity
For air it is .024 W/ m degree i.e. lowest.
Which one of the following forms of water have the highest value of thermal conductivity?
For ice it is 2.25 W/m degree i.e. maximum.
The average thermal conductivities of water and air conform to the ratio
For water it is 0.55-0.7 W/m degree and for air it is .024 W/m degree.
Identify the very good insulator
Glass wool has lowest thermal conductivity of 0.03 W/m degree amongst given option.
Most metals are good conductor of heat because of
For good conductors there must be electrons that are free to move.
Heat conduction in gases is due to
If there is elastic collision then after sometime molecules regain its natural position.
The heat energy propagation due to conduction heat transfer will be minimum for
It is because air has lowest value of thermal conductivity amongst given options.
Cork is a good insulator because
Cork has thermal conductivity in the range of 0.05-0.10 which is very low so it can be porous.
Choose the false statement
Thermal conductivity increase with increase in density of substance.