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प्रश्न
- Assertion (A): The resistance of an intrinsic semiconductor decreases with an increase in its temperature.
- Reason (R): The number of conduction electrons as well as hole increase in an intrinsic semiconductor with the rise in its temperature.
पर्याय
Both Assertion (A) and Reason (R) are true and (R) is the correct explanation of (A).
Both Assertion (A) and Reason (R) are true and (R) is not the correct explanation of (A).
Assertion (A) is true and Reason (R) is false.
Assertion (A) is false and Reason (R) is also false.
उत्तर
Assertion (A) is true and Reason (R) is false.
Explanation:
At room temperature, an intrinsic semiconductor has an equal amount of conduction electrons and holes. However, due to the formation of electron-hole pairs, the quantity of charge carriers (electrons and holes) rises as temperature rises. At higher temperature ranges, this effect is more pronounced. The conductivity of the intrinsic semiconductor increases as the number of charge carriers rises. As a result, as the temperature rises, an intrinsic semiconductor's resistance drops. Intrinsic conduction is the term for this process.
However, Reason (R) is incorrect since an increase in the number of changes transported does not always imply a rise in both electrons and holes. In reality, depending on the material and temperature range, the quantity of electrons and holes might increase or decrease.
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संबंधित प्रश्न
In an intrinsic semiconductor the energy gap Egis 1.2 eV. Its hole mobility is much smaller than electron mobility and independent of temperature. What is the ratio between conductivity at 600K and that at 300K? Assume that the temperature dependence of intrinsic carrier concentration niis given by
`"n"_"i" = "n"_0 exp(- "E"_"g"/(2"k"_"BT"))`
where n0 is a constant.
Let np and ne be the numbers of holes and conduction electrons in an extrinsic semiconductor.
In a semiconductor, the number of holes and number of free electrons are represented as 'nh' and 'ne' respectively. Which one of the following statements is TRUE for the semiconductor?
In a pure or intrinsic semiconductor, valence band holes and conduction-band electrons are always ______.
An intrinsic semiconductor has a resistivity of 0.50 Ω m at room temperature. Find the intrinsic carrier concentration if the mobilities of electrons and holes are 0.39 m2V-1S-1 and O.11 m2 v-1S-1 respectively:
Hole is ______.
Two crystals C1 and C2, made of pure silicon, are doped with arsenic and aluminium respectively.
Why is doping of intrinsic semiconductors necessary?
What is meant by doping of an intrinsic semiconductor?
A pure semiconductor has equal electron and hole concentration of 1016 m-3. Doping by indium increases nh to 5 × 1022 m-3. Then, the value of ne in the doped semiconductor is ______.
Answer the following giving reasons:
Impurities are added to intrinsic semiconductors.