Question

Why temp increase results conductivity of solid decrease?

Answer 1

this is because when the temperature increases random motion of electrons also increases. this results in frequent collisions between the electrons which reduces there current carrying capacity.

Answer 2

Thermal conductivity of any material is dependent on two things:

•Motion of free electrons

•Vibration of molecules

Thermal conductivity is mainly a function of the motion of free electrons.

As the temperature increases, the molecular vibrations increase as energy is supplied inform of heat due to this molecules get energy and vibrate more. So, they obstruct the flow of free electrons, thus reducing the conductivity.

Hope it did a little bit help to you