What phenomenon explains the decrease in resistance in nonmetallic conductors with increase in temperature
The phenomenon that explains the decrease in resistance in nonmetallic conductors with an increase in temperature is called thermally activated conductivity or positive temperature coefficient (PTC) behavior.
In a nonmetallic conductor, such as a semiconductor or an ionic conductor, the electrical conductivity arises mainly from the movement of charged particles (electrons or ions) through the material. These particles are typically confined to specific energy levels or sites within the material's structure.
When the temperature increases, the thermal energy provided to the material causes the charged particles to gain more kinetic energy. Consequently, they can overcome energy barriers or defects in the material more easily and move more freely, resulting in an increase in electrical conductivity.
Additionally, the increase in temperature can also lead to the generation of more free charge carriers through processes like thermal excitation or ionization. These additional carriers contribute to the overall conductivity of the material.
Overall, the increase in temperature enhances the mobility and availability of charge carriers, which leads to a decrease in resistance and an increase in conductivity in nonmetallic conductors.
The phenomenon that explains the decrease in resistance in nonmetallic conductors with an increase in temperature is called "thermistor effect" or "negative temperature coefficient (NTC) effect." In nonmetallic conductors such as semiconductors, the electrical resistance decreases as the temperature increases.
This behavior occurs due to the increase in electron collision and mobility with the increase in temperature. As the temperature rises, the atoms in the material vibrate more vigorously, which leads to more frequent collisions between the charge carriers (electrons) and the atoms. These collisions disrupt the flow of electrons, increasing resistance. However, in nonmetallic conductors such as semiconductors, the increase in temperature also increases the electron mobility, meaning the electrons can move more freely through the material. This increased mobility compensates for the increased collision frequency, resulting in an overall decrease in resistance as temperature rises.