Choose the only false statement from the following
Substances with energy gap of the order of 10 eV are insulators
The conductivity of a semiconductor increases with increases in temperature
In conductors the valence and conduction bands may overlap
The resistivity of a semiconductor increases with increase in temperature
The Correct Option is D
Solution and Explanation
It is nearly hard to give electrons in the valence band enough energy to jump to the conduction band since the energy gap in insulators is of the order of 5 to 10 eV.
More electrons from the valence band of semiconductors jump into the conduction band when the temperature rises, increasing conductivity. In conductors, the conduction band either overlaps the valence band or is just partially filled.
The resistance of semiconductors reduces as temperature rises.
So, option (D): The resistivity of a semiconductor increases with increase in temperature is the only false statement.
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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.