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Physics · Textbook solutions

Semiconductor Electronics: Materials, Devices and Simple Circuits

Every solved example, exercise, and miscellaneous question — in the order the textbook teaches them. · 10 questions

Worked Examples

4 q

Solved Examples

Worked · 4
  1. Eg 14.1
    C, Si and Ge have same lattice structure. Why is C insulator while Si and Ge intrinsic semiconductors?
  2. Eg 14.2
    Suppose a pure Si crystal has 5×1028 atoms m−35 \times 10^{28}\,\text{atoms m}^{-3}. It is doped by 1 ppm concentration of pentavalent As. Calculate the number of electrons and holes. Given that ni=1.5×1016 m−3n_i = 1.5 \times 10^{16}\,\text{m}^{-3}.
  3. Eg 14.3
    Can we take one slab of p-type semiconductor and physically join it to another n-type semiconductor to get p-n junction?
  4. Eg 14.4
    The VV-II characteristic of a silicon diode is shown in the Fig. 14.17. Calculate the resistance of the diode at (a) ID=15 mAI_D = 15\,\text{mA} and (b) VD=−10 VV_D = -10\,\text{V}.

Exercises

6 q
  1. Ex 14.1
    In an n-type silicon, which of the following statement is true:
    1. A.
      Electrons are majority carriers and trivalent atoms are the dopants.
    2. B.
      Electrons are minority carriers and pentavalent atoms are the dopants.
    3. C.
      Holes are minority carriers and pentavalent atoms are the dopants.
    4. D.
      Holes are majority carriers and trivalent atoms are the dopants.
  2. Ex 14.2
    Which of the statements given in Exercise 14.1 is true for p-type semiconductos.
  3. Ex 14.3
    Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to (Eg)C(E_g)_{\text{C}}, (Eg)Si(E_g)_{\text{Si}} and (Eg)Ge(E_g)_{\text{Ge}}. Which of the following statements is true?
    1. A.
      (Eg)Si<(Eg)Ge<(Eg)C(E_g)_{\text{Si}} < (E_g)_{\text{Ge}} < (E_g)_{\text{C}}
    2. B.
      (Eg)C<(Eg)Ge>(Eg)Si(E_g)_{\text{C}} < (E_g)_{\text{Ge}} > (E_g)_{\text{Si}}
    3. C.
      (Eg)C>(Eg)Si>(Eg)Ge(E_g)_{\text{C}} > (E_g)_{\text{Si}} > (E_g)_{\text{Ge}}
    4. D.
      (Eg)C=(Eg)Si=(Eg)Ge(E_g)_{\text{C}} = (E_g)_{\text{Si}} = (E_g)_{\text{Ge}}
  4. Ex 14.4
    In an unbiased p-n junction, holes diffuse from the p-region to n-region because
    1. A.
      free electrons in the n-region attract them.
    2. B.
      they move across the junction by the potential difference.
    3. C.
      hole concentration in p-region is more as compared to n-region.
    4. D.
      All the above.
  5. Ex 14.5
    When a forward bias is applied to a p-n junction, it
    1. A.
      raises the potential barrier.
    2. B.
      reduces the majority carrier current to zero.
    3. C.
      lowers the potential barrier.
    4. D.
      None of the above.
  6. Ex 14.6
    In half-wave rectification, what is the output frequency if the input frequency is 50 Hz50\,\text{Hz}. What is the output frequency of a full-wave rectifier for the same input frequency.