AB PHYSICS SIKHE AASAAN BASHA ME
SUBJEST: PHYSICS CHP: SEMICONDUCTOR WEIGHTAGE: 3 - 4 MARKS
INSTRUCTIONS
1. Solve Lecture Questions (Twice) Once, in Lecture & then
after the Lecture
2. Then Solve Question Bank.
3. Solutions are provided in QB, but Do not refer unless the
Question appears Alien to you
4. QB will only be helpful if you attend lectures.
5. If you have missed Lecture, skipped, or didn't watch 100%,
then question will come in exam from that skipped part
only
WATCH LECTURE
SOLVE QUESTION SOLVE THOSE
BANK QUESTIONS TWICE
AB PHYSICS SIKHE AASAAN BASHA ME
SUBJEST: PHYSICS CHP: SEMICONDUCTOR WEIGHTAGE: 3 - 4 MARKS
SEMICONDUCTOR
CHECKLIST
FULL THEORY
ENERGY BAND DIAGRAM
DOPING
ONE FORMULA
P-N JUNCTION DIODE
AB PHYSICS SIKHE AASAAN BASHA ME
SUBJEST: PHYSICS CHP: SEMICONDUCTOR WEIGHTAGE: 3 - 4 MARKS
Q1) When the conductivity of a semiconductor is only due to breaking of
covalent bonds, the semiconductor is called
A) intrinsic
B) extrinsic
C) p-type
D) n-type
Q2)Basic building blocks of all electronic circuits are
A) devices in which there is a flow of electrons
B) devices in which there is no flow of electrons
C) devices in which there is a controlled flow of electrons
D) devices in which there is an uncontrolled flow of electrons
Q3)GaAs is
A) an elemental semiconductor
B) alloy semiconductor
C) bad conductor
D) metallic semiconductor
Q4) There is no hole current in good conductors, because they
a. have large forbidden energy gap
b. have overlapping valence and conduction bands
c. are full of electron gas
d. have no valence band
Q5) In its crystalline structure, every Si or Ge atoms are attached to other
atoms by
a. coordinate bond
b. electrovalent bond
c. covalent bond
d. hydrogen bond
Q6) Band gap of silicon is Eg (Si), of germanium is Eg (Ge) and of carbon is
Eg (C). The correct order of band gap is
A) Eg(Si) < Eg(Ge) < Eg(C)
A) Eg(Si) > Eg(Ge) < Eg(C)
A) Eg(Si) < Eg(Ge) > Eg(C)
A) Eg(Si) > Eg(Ge) > Eg(C)
Q7)The probability of electrons to be found in the conduction band of an
intrinsic semiconductor at a finite temperature
A) decreases exponentially with increasing band gap
B) increases exponentially with increasing band gap
C) decreases with increasing temperature
D) is independent of the temperature and the ban gap
Q9) Correct order of conductivity for metals, semiconductors and insulators,is
A) semiconductor > metals > insulators
B) metals > semiconductor > insulators
C) semiconductor > insulators > metals
D) insulators > semiconductor > metals
Q10) Reverse bias applied to a p-n junction diode
A) lower the potential barrier
b) decreases the majority charge carriers
C) raises the potential barrier
D) changes the mass of p-n junction diode
Q11) If a p-n junction diode is not connected to any circuit, then
A) the potential is the same everywhere
B) the p-type side has a higher potential than the n-type side
C) there is an electric field at the junction directed from the n-type side to
the p-type side
D) there is an electric field at the junction directed from the p-type side to
the n-type side
Q12) In a middle of the depletion layer of reverse biased, p-n junction, the
A) electric field is zero
B) potential is infinite
C) electric field is maximum
D) potential is zero
Q13) Number of electrons in the valence shell of a intrinsic semiconductor is
A) 1
B) 2
C) 3
D) 4
Q14) In an insulator, the forbidden energy gap between the valence band
and conduction band is of the order of
A) 1 MeV
B) 0.1 MeV
C) 1 eV
D) 5 eV
Q15) In semiconductors, at room temperature the
A) valence band is partially empty and the conduction band is partially filled
B) valence band is completely filled and the conduction band is
partially filled and the conduction band is partially filled
C) valence band is completely filled
D) conduction band is completely empty
Q16) The energy band gap of Si is
A) 0.70 eV
b) 1.1 eV
C) between 0.70 eV to 1.1 eV
D) 5 eV
Q17) Eg for silicon is 1.12 eV and that for germanium is 0.72 eV. Therefore,
it can be concluded that
A) more number of electron-hole pairs will be generated in silicon that in
germanium at room temperature
b) less number of electron-hole pairs will be generated in silicon than in
germanium at room temperature
C) equal number of electron-hole pairs will be generated in both at
lower temperatures
D) equal number of electron-hole pairs will be generated in both at
higher temperatures
Q18) Hole is
A) an anti-particle of electron
B) a vacancy created when an electron leaves a covalent bond
C) absence of free electrons
D) an artificially created particle
Q19) Intrinsic semiconductor is electrically neutral. Extrinsic
semiconductor having large number of current carriers would be
A) positively charged
B) negatively charged
C) both number density of carries and relaxation time increase
D) number density of carries increases, relaxation time decreases but
effect of decrease in relaxation time is much less than increase in number
density
Q20) He drift current in a p-n junction is
A)from the n-side to the p-side
b)relaxation time increases
C)from the n-side to the p-side, if the junction is forward biased and in
the opposite direction, if it is reverse biased
D)from the p-side to the n-side, if the junction is forward biased and in
the opposite direction, if it is reverse biased
Q21) he diffusion current in a p-n junction is
A)from the n-side to the p-side
b)from the p-side to the n-side
C)from the n-side to the p-side, if the junction is forward biased and in
the opposite direction, if it is reverse biased
D)from the p-side to the n-side, if the junction is forward biased and in
the opposite direction, if it is reverse biased
SOLUTIONS
