question_answer

The valence of an impurity added to germanium crystal in order to convert it into a P-type semi conductor is [MP PMT 1989; CPMT 1987]

A)            6    

B)            5

C)            4    

D)            3

Correct Answer: D

Solution :

           \[Ge\]+  \[\begin{align}   & \text{Trivalent} \\  & \text{ impurity}\,\,\,\,\, \\ \end{align}\]      \[\begin{align}   & P\text{-type}\,\, \\  & \text{semiconductor} \\ \end{align}\]