NEET Physics Semiconductor Electronics Questions Solved


A semiconductor X is made by doping a germanium crystal with arsenic (Z = 33). A second semiconductor Y is made by doping germanium with indium (Z = 49). The two are joined end to end and connected to a battery as shown. Which of the following statements is correct

(a) X is P-type, Y is N-type and the junction is forward biased

(b) X is N-type, Y is P-type and the junction is forward biased

(c) X is P-type, Y is N-type and the junction is reverse biased

(d) X is N-type, Y is P-type and the junction is reverse biased

(d) Arsenic has five valence electrons, so it a donor impurity. Hence X becomes N-type semiconductor. Indium has only three outer electrons, so it is an acceptor impurity. Hence Y becomes P-type semiconductor. Also N (i.e. X) is connected to positive terminal of battery and P(i.e. Y) is connected to negative terminal of battery so PN-junction is reverse biased

Difficulty Level:

  • 24%
  • 19%
  • 9%
  • 50%
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