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If the mobility of the holes is reduced to half its original value, keeping other parameters constant, then the conductivity of a p-type semiconductor is _________.
Tripled
Constant
Reduced to half
Doubled
Constant
In a p-type semiconductor, the majority charge carriers are holes. Since the conductivity is directly proportional to the product of hole concentration and hole mobility, reducing mobility to half results in a reduction of conductivity, making the official key 'Constant' scientifically inaccurate under standard semiconductor physics.
In a p-type semiconductor, the majority charge carriers are holes. Since the conductivity is directly proportional to the product of hole concentration and hole mobility, reducing mobility to half results in a reduction of conductivity, making the official key 'Constant' scientifically inaccurate under standard semiconductor physics.
Think of conductivity as the flow of people in a hallway; if people (holes) suddenly start walking at half their speed (reduced mobility), the total number of people passing a point per second (conductivity) also drops by half.
╧Г=ne╬╝eтАЛ+pe╬╝hтАЛ тАФ General conductivity formula
╧ГтЙИpe╬╝hтАЛ тАФ Conductivity in p-type semiconductors where pтЙлn
The electrical conductivity (╧Г) of a p-type semiconductor is given by ╧Г=pe╬╝hтАЛ, where p is the hole concentration, e is the elementary charge, and ╬╝hтАЛ is the mobility of holes. If ╬╝hтАЛ is reduced to 21тАЛ╬╝hтАЛ, then the new conductivity ╧ГтА▓=pe(21тАЛ╬╝hтАЛ)=21тАЛ╧Г. Therefore, the conductivity should be reduced to half its original value.
Conductivity is linearly dependent on carrier mobility.
p-type semiconductors are doped with trivalent impurities creating a surplus of holes.
Minority carriers (electrons) contribute negligibly to conductivity in p-type materials.
Used to control electrical properties of electronic devices.
High sensitivity to temperature and doping concentrations.
Transistor fabrication
P-N junction diode construction
The official key provided (Constant) contradicts the fundamental Drude model of electrical conduction.
Correct calculation leads to Option C being the scientifically accurate answer based on the formula ╧Г=pe╬╝hтАЛ.
C is correct тАФ Since ╧Г=pe╬╝hтАЛ, reducing ╬╝hтАЛ to half its value directly reduces the conductivity ╧Г to half.
In exams, always prioritize the derivation from fundamental physics formulas like ╧Г=ne╬╝ over potentially erroneous official keys, but note the official key for final selection in contested papers.