question_answer

The valence of the impurity atom that is to be added to germanium crystal so as to make it a N-type semiconductor, is  [MNR 1993; MP PET 1994; CBSE PMT 1999; AIIMS 2000]

A)            6    

B)            5

C)            4    

D)            3

Correct Answer: B

Solution :

           \[Ge\] + \[\begin{matrix}   \text{Pantavalent} \\   \text{ impurity} \\ \end{matrix}\]         \[\begin{align}   & N\text{-type}\,\, \\  & \text{semiconductor} \\ \end{align}\]