26. The unidirectional property of a pn-junction is useful for its use as a

1. 1. Rectifier

   
   
   

   2. Oscillator

   
   
   

   3. Rectifier

   
   
   

   4. Transformer

   
   
   

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   NA

   Correct Option: A

   NA

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27. In a p-type semiconductor the majority charge carriers are

1. 1. Electrons

   
   
   

   2. Holes

   
   
   

   3. Neutrons

   
   
   

   4. Protons

   
   
   

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   NA

   Correct Option: B

   NA

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28. When arsenic is added as an impurity to silicon, the resulting material is

1. 1. n-type semiconductor

   
   
   

   2. p-type semiconductor

   
   
   

   3. n-type conductor

   
   
   

   4. None of these

   
   
   

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   NA

   Correct Option: A

   NA

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29. The impurity atoms with which pure silicon should be doped to make a p-type semiconductor are those of

1. 1. Phosphorus

   
   
   

   2. Boron

   
   
   

   3. Aluminium

   
   
   

   4. Both (b) and (c)

   
   
   

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1. View Hint View Answer Discuss in Forum

   NA

   Correct Option: D

   NA

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