162. The diffusion length of a carrier depends on
A. the shape of the semiconductor
B. the life time of the carriers alone
C. the mobility and life time of the carriers
D. the mobility of the carriers alone

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163. A germanium atom contains
A. four protons
B. four valence electrons
C. six valence electrons
D. only two electrons

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164. A normal atom is one which
A. always has an atoms core with a charge of +4
B. always has four valence electtons.
C. has equal numbers of electrons and protons
D. shares its electrons with other stoms.

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165. When atoms are held together by the sharing of valence electrons
A. they form a covenant bond.
B. they always form a diamond lattice structure
C. the valence electrons are free to move away from the atom.
D. such shared electron leaves a hole.

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166. In the diamond lattice structure of germanium or silicon crystal
A. each atom is equidistant from four other atoms
B. each atom is equidistant from six other atoms
C. the atomic cores are free to move about.
D. the atomic cores have a charge of +6.

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167.  An electron in the conducting band
A. is located near the top of the crystal.
B. has no charge.
C. has a higher energy than an election in the valence band.
D. is bound to its parent atom.

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168. An intrinsic semiconductor at absolute Zero temperature
A. behaves like an insulator
B. behaves like a metallic conductor
C. has a large number of holes
D. has a few holes and a few free electrons

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