Match List-I with List-II
|
List-I |
List-II |
|
(A) Intrinsic semiconductor |
(I) Number of conduction electrons >> number of holes |
|
(B) n-type semiconductor |
(II) Number of conduction electrons << number of holes |
|
(C) p-type semiconductor |
(III) Net current is zero |
|
(D) p-n junction under equilibrium |
(IV) Number of conduction electrons = number of holes |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(IV), (B)-(I), (C)-(II), (D)-(III)
|
List-I |
List-II |
|
(A) Intrinsic semiconductor |
(IV) Number of conduction electrons = number of holes |
|
(B) n-type semiconductor |
(I) Number of conduction electrons >> number of holes |
|
(C) p-type semiconductor |
(II) Number of conduction electrons << number of holes |
|
(D) p-n junction under equilibrium |
(III) Net current is zero |
(A) Intrinsic Semiconductor
An intrinsic semiconductor is a pure semiconductor without any significant dopant species present.
- Logic: Charge carriers are generated solely by thermal excitation, which creates an electron-hole pair. Therefore, the number of conduction electrons ($n_e$) is exactly equal to the number of holes ($n_h$).
- Matches with (IV): Number of conduction electrons = number of holes.
(B) n-type Semiconductor
An n-type semiconductor is created by adding pentavalent impurities (like Phosphorus) to an intrinsic semiconductor.
- Logic: These impurities provide extra electrons to the conduction band. Consequently, electrons become the majority carriers.
- Matches with (I): Number of conduction electrons >> number of holes.
(C) p-type Semiconductor
A p-type semiconductor is created by adding trivalent impurities (like Boron) to an intrinsic semiconductor.
- Logic: These impurities create "holes" (vacancies) in the valence band that can accept electrons. Consequently, holes become the majority carriers.
- Matches with (II): Number of conduction electrons << number of holes.
(D) p-n Junction under Equilibrium
In a p-n junction at equilibrium (with no external voltage applied), a depletion region forms.
- Logic: Diffusion current and drift current oppose each other perfectly. While there is internal movement of charges, there is no external flow of charge through the device.
- Matches with (III): Net current is zero.