Semicon Basics

The nucleus of an atom consists of

• protons and neutrons

• electrons

• electrons and protons

• electrons and neutrons

A positive ion is formed when

• a valence electron breaks away from the atom

• there are more holes than electrons in the outer orbit

• two atoms bond together

• an atom gains an extra valence electron

The energy band in which free electrons exist is the

• first band

• second band

• conduction band

• valence band

The current in a semiconductor is produced by

• electrons only

• holes only

• negative ions

• both electrons and holes

In an intrinsic semiconductor

• there are no free electrons

• the free electrons are thermally produced

• there are only holes

• none of these is true

In a semiconductor crystal, the atoms are held together by

• the interaction of valence elctrons

• forces of attraction

• covalent bonds

• all of these are true

A trivalent impurity is added to silicon to create

• germanium

• a p-type semiconductor

• an n-type semiconductor

• a depletion region

The purpose of pentavalent impurity is to

• reduce the conductivity of silicon

• increase the number of holes

• increase the number of free electrons

• create minority carriers

The majority carriers in an n-type semiconductor are

• holes

• valence electrons

• conduction electrons

• protons

The most widely used semiconductive material in electronic devices is

• germanium

• carbon

• copper

• silicon