MCQ on Semiconductor Material

MCQ on Semiconductor Material

MCQ on Semiconductor Material, Multiple Choice Questions on Semiconductor Material, Engineering Physics MCQ, Engineering MCQ, Electronics Device & Circuit MCQ, Semiconductor Physics Multiple Choice Questions

Multiple Choice Questions

Q.1. Which of the following, has the lowest temperature coefficient of resistivity.

Alum Silver, Copper, Gold, Aluminium

  • Copper 
  • Silver
  • Gold
  • Aluminium 

Answer: Gold

Q.2. In a metal

  • The electrical conduction is by electrons and holes
  • With rise in temperature, the conductivity decreases
  • The conduction band is empty
  • There is a small energy gap between the two bands

Answer: With a rise in temperature, the conductivity decreases

Q.3. The forbidden energy gap in semiconductors:

  • lies just below the valence band
  • is the same as the valence band
  • lies just above the conduction band
  • lies between the valence band and the conduction band

Answer: lies between the valence band and the conduction band

Q.4. The conduction band of a semiconductor material may be

  • completely filled
  • partially filled
  • empty
  • none

Answer: partially filled

Q.5. The energy band which possesses the free electrons is called:

  • valence band
  • conduction band
  • forbidden band
  • none of these

Answer: conduction band

Q.6. Which of the following behaves as an insulator.

  • Diamond
  • Germanium
  • Silicon
  • Silver

Answer: Diamond

Q.7. The unit of mobility of charge carriers is

  • m2/volt-sec
  • m/volt-sec2
  • m3/volt-sec
  • m/volt-sec

Answer: m2/volt-sec

Q.8. A semiconductor is electrically neutral because it has:

  • no majority carriers
  • no minority carriers
  • no free carriers
  • equal number of positive and negative carriers

Answer: an equal number of positive and negative carriers

Q.9. An intrinsic semiconductor at absolute zero temperature

  • has large number of holes
  • has a few hole and same number of electrons
  • acts as an insulator
  • acts as metallic character

Answer: acts as an insulator

Q.10. When the temperature of an intrinsic semiconductor is increased

  • resistance of semiconductor is also increased
  • conductivity is decreased
  • energy of atoms is increased
  • holes are created

Answer: energy of atoms is increased

Q.11. A doner-type impurity

  • is used to obtain a p-type semiconductor
  • is used to obtain a N-type semiconductor
  • must possess three valence electrons
  • cannot be used in silicon crystals

Answer: is used to obtain an N-type semiconductor

Q.12. If a small amount of antimony is added to Ge

  • the resistance is increased
  • Ge will become a p-type semi-conductor
  • antimony becomes an acceptor impurity
  • there will be no more free electrons than holes in a semiconductor

Answer: there will be no more free electrons than holes in a semiconductor

Q.13. In an N-type semiconductor, the concentration of minority carriers mainly depends upon

  • doping technique
  • number of donor atoms
  • temperature of material
  • quality of intrinsic materials Ge or Si

Answer: temperature of material

Q.14. In a P-type semiconductor, majority carriers are

  • holes
  • electrons
  • both
  • none of the above

Answer: holes

Q.15. Which of the following atoms can be used as a p-type impurity

  • Boron
  • Arsenic
  • Antimony
  • Phosphorus  

Answer: Boron

Q.16. In an intrinsic semiconductors, the Fermi level lies:

  • in the middle of conduction band (CB) and valence band (VB)
  • near CB
  • near VB
  • none of these

Answer: in the middle of CB and VB

Q.17. 10-9 ohm-m is the resistivity of

  • Aluminium
  • Sodium
  • Bismuth
  • Nickel

Answer: Nickel

Q.18. Due to the illumination of light, the electron and hole concentrations in a heavily doped n-type semiconductor, increase by Δn and Δp respectively. If ni is the intrinsic concentration, then

  • \Delta n < \Delta p
  • \Delta n > \Delta p
  • \Delta n = \Delta p
  • \Delta n \times \Delta p = n_{i}^{2}

Answer: \Delta n \times \Delta p = n_{i}^{2}

Q.19. The current density Jo of electrons through any conductor carrying current is given by:

  • J_{0}=\frac{ne\tau E}{m}
  • J_{0}=\frac{ne\tau E^{2}}{m}
  • J_{0}=\frac{ne^{2}\tau E}{m}
  • J_{0}=\frac{e^{2}\tau E}{m}

Answer: J_{0}=\frac{ne^{2}\tau E}{m}

Q.20. An element used in semiconductors whose atoms have three valence electrons is

  • Germanium
  • A donor
  • An acceptor
  • Silicon

Answer: An acceptor

Q.21. The Hall coefficient RH is defined by

  • R_{H}=\frac{V_{H}.t}{B}
  • R_{H}=\frac{V_{H}B}{It}
  • R_{H}=\frac{V_{H}t}{B}
  • R_{H}=\frac{V_{H}t}{BI}

Answer: R_{H}=\frac{V_{H}t}{BI}

Q.22. The probability of occupation F(E) of an energy level E by an electron is given by

  • F(E)=[1+e^{(E-E_{F})}/kT]
  • F(E)=\frac{1}{1+e^{(E_{F}-E)}/kT}
  • F(E)=\frac{1}{1+e^{(E-E_{F})}/kT}
  • F(E)=\frac{1}{1-e^{(E-E_{F})}/kT}

Answer: F(E)=\frac{1}{1+e^{(E-E_{F})}/kT}

Q.23. For high conductivity and large temperature coefficient

  • Pure metals are chosen
  • Slightly impure materials are used
  • Alloys are used
  • Super-conductors are used

Answer: Pure metals are chosen

Q.24. The potential barrier at a pn junction is established due to the charge on either side of the Junction. These charges are

  • majority carriers
  • minority carriers
  • both a and b
  • donor and acceptor ions

Answer: donor and acceptor ions

Q.25. In a PN junction, holes diffuse from the p-region to the n-region because

  • they move across the junction by the potential diffierence
  • free electron available in the n-region attract them
  • the holes concentration in the p-region is greater as compared to n-region
  • all of these

Answer: the holes concentration in the p-region is greater as compared to n-region

Q.26. In a crystal diode, the barrier potential offers opposition to only

  • free electrons in n-region
  • holes in p-region
  • majority carriers in both regions
  • minority carriers in both regions

Answer: majority carriers in both regions

Q.27. When a reverse bias is applied to a crystal diode, it

  • raises the potential barrier
  • lowers the potential barrier
  • increases the majority-carrier current greatly
  • none of these

Answer: raises the potential barrier

Q.28. At reverse bias, the number of minority carriers crossing the junction of a diode depends primarily on the

  • concentration of doping impurities
  • rate of thermal generation of electron-hole pairs
  • magnitude of the potential barriers
  • all of these

Answer: all of these

Q.29. When a forward bias is applied to a crystal diode, it

  • raises the potential barrier
  • lowers the potential barrier
  • reduces the majority-carrier current to zero
  • none of these

Answer: lowers the potential barrier

Q.30. Avalanche breakdown in a crystal diode occurs when

  • the potential barrier is reduced to a zero
  • forward current exceeds a certain value
  • reverse bias exceeds a certain value
  • all of these

Answer: reverse bias exceeds a certain value

Semiconductor Diode MCQ

Leave a Reply

Your email address will not be published.