Class 12 Semiconductor Electronics CBSE Questions & Answers

Class 12 · Semiconductor Electronics

This is Physics Class 12 Semiconductor Electronics CBSE Questions & Answers. There are 15 questions in this test with each question having around four answer choices.

Questions & Answers

1
The conductivity of P – type semiconductor is due to
  • A
    holes
    Correct
  • B
    none of the above.
  • C
    electrons
  • D
    both electrons and holes
2
An N-type Ge is obtained on doping the Ge- crystal with
  • A
    phosphorus
    Correct
  • B
    boron
  • C
    gold
  • D
    aluminum
3
A P – type crystal is obtained by doping A) silicon with arsenic, B) silicon with aluminum, C) Ge with boron, D) Ge with phosphorus, Hence, say whether
  • A
    (A and C) are correct
  • B
    (B and C) are correct
    Correct
  • C
    (B and D) are correct
  • D
    (A and D) are correct
4
Majority current carriers in N – types are
  • A
    holes
  • B
    electrons
    Correct
  • C
    negative ions
  • D
    positive ions
5
A solid having uppermost energy – band partially filled with electrons is called
  • A
    a semi – conductor
  • B
    an insulator
  • C
    none of the above
  • D
    a conductor
    Correct
6
The number of valence electrons in a good conductor is generally
  • A
    five
  • B
    three or less than three
    Correct
  • C
    four
  • D
    six or more than six
7
Electrons are forbidden in a band (in a crystal) called the
  • A
    conduction band
  • B
    one of the above
  • C
    forbidden band
    Correct
  • D
    valence band
8
The behavior of Ge as a semi – conductor is due to the width of
  • A
    forbidden band being small and narrow
    Correct
  • B
    forbidden band being large
  • C
    conduction band being large
  • D
    conduction band being small and narrow
9
P-N junction can be used as
  • A
    an amplifier
  • B
    a rectifier
    Correct
  • C
    a modulator
  • D
    an oscillator
10
To provide the abundance of holes the impurity added should be
  • A
    trivalent
    Correct
  • B
    monovalent
  • C
    pentavalent
  • D
    tetravalent
11
For forward biasing a P-N junction the positive terminal of the battery is connected to
  • A
    P – type crystal
    Correct
  • B
    Either P –type or N – type crystal
  • C
    Neither P – type nor N – type crystal
  • D
    N – type crystal
12
The number of junctions in a transistor is/are
  • A
    one
  • B
    three
  • C
    two
    Correct
  • D
    four
13
The number of terminals in a transistor is/are
  • A
    one
  • B
    four
  • C
    Three
    Correct
  • D
    two
14
To produce N – type crystal Ge or Si may be doped with a substance that is
  • A
    pentavalent
    Correct
  • B
    tetravalent
  • C
    divalent
  • D
    trivalent
15
Transistor was invented by
  • A
    Fleming
  • B
    Lee de Forest
  • C
    Shockley
    Correct
  • D
    Marconi