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WorksheetsEC8252- ELECTRON DEVICES - UNIT 1
Total questions: 25
Worksheet time: 13mins
In a semiconductor which of the following carries can contribute to the current?
Electrons
Holes
Both
None
Electrons from valence band rises to conduction band when the temperature is greater than 0 k. Is it True or False?
True
False
The thermal equilibrium concentration of the electrons in the conduction band and the holes in the valence band depends upon?
Effective density of states
Fermi energy level
Both A and B
Neither A nor B
In which of the following semiconductor, the concentration of the holes and electrons is equal?
Extrinsic
Compound
Intrinsic
None
Single-element semiconductors are characterized by atoms with ____ valence electrons.
2
3
4
5
There is a small amount of current across the barrier of a reverse-biased diode. This current is called as
Reverse breakdown current
Conventional current
Reverse leakage current.
Forward-bias current
Doping of a semiconductor material is termed as
adding of impurities to increase the resistance of the material.
adding of impurities to hold the material together.
adding of impurities to decrease the resistance of the material
Removing of impurities to get pure silicon
The term bias in electronics usually means
the value of dc voltages for the device to operate properly.
the value of ac voltage in the signal.
the condition of current through a pn junction
reverse saturation current in the pn junction
Which is an example for Intrinsic semiconductor
Gallium Arsenide
Germanium
Indium phosphate
None of the above
What types of impurity atoms are added to increase the number of conduction-band electrons in intrinsic silicon?
octavalent
pentavalent
trivalent
bivalent
The most commonly used semiconductor material is
Germanium
Silicon
Indium
Phosphide
An atom is made up of
protons
electrons
neutrons
all of the above
The forward voltage across a conducting silicon diode is about
0.6 V
0.4 V
0.3 V
0.7 V
Which statement best describes an insulator?
A material with few free electrons
A material doped to have some free electrons.
A material with many free electrons.
None of the above
What is the difference between the practical value and theoretical value of ni?
Factor of 3
Factor of 2
Factor of 4
Factor of 1
Holes in the n-type materials are called
majority carriers
minority carriers
zero carriers
None of the above
When temperature increases intrinsic concentration increases which results increase in
conductivity
resistivity
capacitance
inductance
Semiconductor material doped with trivalent impurity is called as
p-type
n-type
neutral
intrinsic
Antimony is a
trivalent impurity
pentavalent impurity
divalent impurity
bivalent impurity
In metals conductivity takes place due to
Holes
Free electrons
Valence Electrons
neutrons
When electron jumps to conduction band,a vacancy is left in the
conduction band
nucleus
valence band
none of the above
Copper and gold are good
insulator
conductor
semiconductor
None of the above
