Voltage and Current - Technical MCQs

Q1:

An atom of a semiconductor has _______________ electrons in the valence shell.

A 4

B 8

C 2

D 0

ANS:A - 4

In silicon or germanium atoms outermost orbit has requires 8 electrons but these gives only 4 electrons. From the concept of intra atomic space these completely filled 4 electrons are called valence band and empty band is called conduction band. Hence valence band has 4 electrons in semiconductors.