The effect of increase in temperature on the number of electrons in conduction band $\left( n _{ e }\right)$ and resistance of a semiconductor will be as:
The effect of increase in temperature on the number of electrons in conduction band $\left( n _{ e }\right)$ and resistance of a semiconductor will be as:
Show Hint
- $n _{ e }$ decreases, resistance increases
- Both $n _{ e }$ and resistance increase
- $n _{ e }$ increases, resistance decreases
- Both $n_e$ and resistance decrease
The Correct Option is C
Solution and Explanation
This phenomenon is observed in semiconductors, where the conductivity significantly improves with temperature. In conductors, however, the increase in temperature typically causes the atoms to vibrate more, which leads to an increase in scattering of the free electrons, thereby increasing the resistance.
The relationship between conductivity and temperature is especially important in devices like thermistors, where the resistance changes significantly with temperature. Positive temperature coefficient (PTC) thermistors show an increase in resistance with temperature, while negative temperature coefficient (NTC) thermistors exhibit the opposite behavior, which makes them useful for temperature sensing and circuit protection applications.
In summary, for most semiconductors, as temperature rises, the number of charge carriers increases, which lowers the resistance, making these materials more conductive. However, in metals and conductors, increased temperature leads to higher resistance due to increased atomic vibrations.
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Concepts Used:
Semiconductors
Semiconductors are a crystalline solid materials, whose electrical conductivity lies between a conductor and an insulator. Semiconductors are mainly used in the manufacturing of electronic devices like capacitors, transistors, diodes, Integrated circuits, etc.
Properties of Semiconductor:
- Semiconductor acts like an insulator at Zero Kelvin. On increasing the temperature, it works as a conductor.
- Due to their exceptional electrical properties, semiconductors can be modified by doping to make semiconductor devices suitable for energy conversion, switches, and amplifiers.
- Lesser power losses.
Uses of Semiconductor:
- Semiconductors are widely used in manufacturing electronics devices like transistors, diodes, sensors, integrated circuits.
- Semiconductors are widely used in all electronic devices, like mobile phones, digital cameras, communication devices, trains, ATMs, etc.