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Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsSemiconductor Electronic: Material, Devices And Simple Circuits1 Mark
Question
Two statements are given-one labelled Assertion (A) and the other labelled Reason (R). Select the correct answer to these questions from thecodes(a), (b), (c) and (d) as given below.
  1. Both A and R are true and R is the correct explanation of A.
  2. Both A and R are true but R is not the correct explanation of A.
  3. A is true but R is false.
  4. A is false and R is also false.
Assertion: The probability of electrons to be found in the conduction band of an intrinsic semiconductor at a finite temperature decrease exponentially with increasing band gap.
Reason: It will be more difficult for the electron to cross over the large band gap while going from valence band to conduction band.
✓

Answer

  1. Both A and R are true and R is the correct explanation of A.
Explanation:

For electron to jump from valence band to conduction band needs energy equal or more than the forbidden band between these two band. As the energy of band gap increases, it becomes difficult for electron to get that equivalent energy.

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