Q 12-03-297NEETNEET 2022Top questionEasy
As the temperature increases, the electrical resistance
Answer: (D) Increases for conductors but decreases for semiconductors
In a metal the number of free electrons is fixed; heating makes the ions vibrate more, so collisions are more frequent, the relaxation time falls and the resistance rises.
In a semiconductor heating breaks more covalent bonds, so the number of charge carriers rises sharply. This outweighs the extra collisions and the resistance falls.
Solution by Sreeraj P, M.Sc Physics