A Best Way To Crack Gorenment Job Exams

Electrical Engineering Objective Questions { Material And Components }



120. If indium impurity is added to germanium
A. it creates excess electrons
B. it results in hole density to exceed free electron density
C. it causes increase in resistance of Ge sample
D. it results in a new energy level just below conduction level
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121. A hole shifts its position basically due to
A. a valence electron from a neighbouring atom joinging the hole to fill the vacancy
B. breaking of covalent band
C. movement of atomic core
D. increase in temperature
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122. In n-type semiconductor
A. holes form the monority carrier
B. electrons form the majority carriers
C. impurity is trivalent
D. free electron density equals the hole density
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123.  In p-type semiconductor
A. holes from the monority carrier
B. free electrons from the minority carriers
C. hole density equals free electron density
D. impurity is pentavalent
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124.  Drift current in germanium is caused by
A. thermal agitation of crystal lattice
B. concentration gradient of charge carriers
C. applied electric field
D. incidence of light
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125.  Donor impurity in germanium results in
A. increased forbidden energy gap
B. reduced forbidden energy gap
C. a narrow energy band slightly below
D. new discrete energy level slightly below cunduction level
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126.  Acceptor impurity atoms in silicon results in
A. increased forbidden energy gap
B. reduced forbidden energy gap
C. new discrete energy level slightly below conduction band
D. new disFrete energy level slightly above valence level
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