🧪 Semiconductor MCQ Quiz Hub

1. As the temperature of a semiconductor increases its
Conductivity increases
Resistivity increases
Atomic number decreases
Temperature co-efficient becomes zero

2. Which of the following doping elements would not be suitable for converting intrinsic semiconductor
Phosphorous
Indium
Antimony
Arsenic

3. The forward region of a semiconductor diobe characteristic curve is where diode appears as
High resistance
An ON switch
An OFF switch
A capacitor

4. In a semiconductor diode, the barrier offers opposition to
Majority carriers in both regions
Majority as well as minority carriers in both regions
all of the above
None of the mentioned

5. In case of semiconductors, recombination is merging of
An electrons with a hole
An outside electron with semiconductor electrons
Two or more electrons
Two or more holes

6. The conduction band
Is always above the forbidden energy level
Is the region of free electrons
Concentrates holes for the flow of current
Is a range of energies corresponding to the energies of the free electrons

7. The temperature co-efficient of an intrinsic semiconductor is.......
Zero
Positive
Negative
None of them

8. The temperature co-efficient of an extrinsic semiconductor is.......
Zero
Positive
Negative
none of the above

9. ....... has the highest mobility.
Electron
Positive ions
Negative ions
Neutron

10. At room temperature N-type material will have....
More of electrons
More of holes
Equal number of electrons and holes
None of the mentioned

11. A room temperature P-type material will have....
More of electrons
More of holes
Equal number of electrons and holes
None of the mentioned

12. Nucleus is made of
Electrons and protons
Photons and neutrons
Photons and neutrons
Photons and electrons

13. Consider the energy level diagram of an intrinsic semiconductor. The Fermi level lies in the
Valence band
Forbidden band or
Conduction band or
It can be at any of the above locations depending upon the doping concentration and temperature

14. In any specimen the Hall voltage is proportional to magnetic field β as
β
β2
1/β
1/β2

15. Intrinsic concentration of charge carriers in a semiconductor varies as
T3
T2
T
1/T

16. The dynamic resistance of a diode varies as
I the current
I2
1/I
1/I2

17. The forbidden band in germanium at 00K is
0.03 eV
0.785 eV
1.5 eV
2.0 eV

18. The atomic number of germanium is.......
4
8
16
32

19. Which of the following elements belog to the same group of periodic tables as that of silicon and germanium
Phosphorous
Carbon
Sodium
Boron

20. .... is used to describe the static V/I characteristic of a junction diode
Bolzmann diode equation
Richardson-Dushman equation
Child's Three half-power law
Einstein's photoelectric equation

21. Acceptor-type impurities
Can be added to silicon but not to germanium
Create excess electrons
Must have three velence electrons
Must have five valence electrons

22. The movement of a hole results from.......
Excitation due to high temperature
Change in number of protons in the atom
The vacancy filled by a valence electron from the neighbouring atom
None of above

23. For a germanium P-N junction, the barrier potential is nearly.......
0.15 V
0.3 V
0.45 V
0.6 V/span>

24. For a silicon P-N junction, the barrier potential is about
0.7 V
0.8 V
0.9 V
1.0 V

25. In order to obtain a P-type germanium, the germanium should be doped with a ........ impurity
Trivalent
Tetravalent
Pentavalent
Any of the above

26. ...... are immobile.
Ions
Electrons
Holes
none of the above

27. A zener diode is invariably used with
Reverse bias
Forward bias
Zero bias
Any of the above

28. The crystal diode is used as a
Rectifer
Amplifier
Oscillator
Any of the above

29. Ripple factor is the ratio of ...value to ... value
r.m.s., peak
peak, D.C
r.m.s., D.C
peak, r.m.s

30. Addition of impurity in the ratio of 1 in 10 to a pure or intrinsic semiconductor
Increases its conductivity nearly 10 times
Increases its conductivity nearly 100 times
Decreases its conductivity nearly 100 times
Increases its resistivity nearly 100 times

31. With increases of reverse bias, the reverse saturation current in P-N diode
Increases
Remains constant
Increases
Increases as inverse of reverse bias

32. The maximum reverse voltage that can be applied to an ordinary semiconductor diode without irreverslible damage is called .....
Cut-off voltage
Avalanche breakdown voltage
Peak inverse voltage
Zener voltage

33. The resistivity of a semiconductor lies
Below 10-6
Between 10-6 to 102 ohm-metre
Between 10-6 to 104 ohm-metre
Above 104 ohm-metre

34. Which of the following materials can be used to make a light-emitting diode?
Silicon
Germanium
Gallium arsenide
Phosphorescent material

35. Which of the following is an active device?
Electric bulb
Transformer
SCR
Loudspeaker

36. Which of the following is a passive component?
Vacumm tube devices
Capacitors
Semiconductor devices
All of the above

37. For a half wave rectified sine wave the ripple factor is
1.65
1.45
1.21
1.00

38. A semiconductor is formed by …….. bonds.
covalent
electrovalent
co-ordinate
none of the above

39. A semiconductor has …….. temperature coefficient of resistance.
positive
zero
negative
none of the above

40. The most commonly used semiconductor is ……..
germanium
silicon
carbon
Sulphur

41. A semiconductor has generally …….. valence electrons.
2
3
6
4

42. The resistivity of pure germanium under standard conditions is about ……..
6 × 104 Ω cm
60 Ω cm
3 × 106 Ω cm
6 × 10−4 Ω cm

43. The resistivity of pure silicon is about ……..
100 Ω cm
6000 Ω cm
3 × 105 Ω cm
1.6 × 10− 8 Ω cm

44. When a pure semiconductor is heated, its resistance ……..
goes up
goes down
remains the same
cannot say

45. The strength of a semiconductor crystal comes from ……..
forces between nuclei
forces between protons
electron-pair bonds
none of the above

46. When a pentavalent impurity is added to a pure semiconductor, it becomes ……..
an insulator
an intrinsic semiconductor
p-type semiconductor
n-type semiconductor

47. Addition of pentavalent impurity to a semiconductor creates many ……..
free electrons
holes
valence electrons
Bound electrons

48. A pentavalent impurity has …….. valence electrons.
3
5
4
6

49. A trivalent impurity has …….. valence electrons.
4
5
6
3

50. A hole in a semiconductor is defined as ……..
a free electron
the incomplete part of an electron pair bond
a free proton
A free neutron