# MCQs / Engineering Reviewer - Solid State Devices Part 1 MCQs - Solid State Devices
Multiple Choice Questions / Practice Test
Solid State Devices

1. How many electrons are there in the fourth orbit of a copper atom?
A. 1
B. 2
C. 3
D. 4

2. The maximum permissible number of electrons in the third orbit is
A. 18
B. 8
C. 32
D. 2

3. Varactor diodes are commonly used
A. As voltage controlled capacitance
B. As a constant current source
C. As voltage multiplier
D. As a constant voltage source

4. The reason why electrons are not pulled into the nucleus of an atom.
A. Because of the centrifugal or outward force created by their orbital motion.
B. Because of the force of attraction between them and the nucleus is weak.
C. Because they are not being attracted by the positive nucleus.
D. Because of the strong bonding between them that resists any force pulling them towards the nucleus.

5. The electrons in the largest orbit travel ________ than the electrons in the smaller orbits.
A. More slowly
B. Faster
C. In the same velocity
D. A little bit slower

6. A transistor configuration with the lowest current gain.
A. Common base
B. Common emitter
C. Common collector
D. Emitter-follower

7. A semiconductor in its purest form is called
A. Pure semiconductor
B. Doped semiconductor
C. Intrinsic semiconductor
D. Extrinsic semiconductor

8. Valence orbit is the other form for
A. Outer orbit
B. 3rd orbit
C. 4th orbit
D. 2nd orbit

9. K shell means
A. First orbit
B. 2nd orbit
C. 3rd orbit
D. 4th orbit

10.  For either germanium or silicon diodes, the barrier potential decreases _______ for each Celsius degree rise.
A. 1 mV
B. 3 mV
C. 4 mV
D. 2 Mv

11. A diode modeling circuit which considers the threshold voltage, average resistance and switch as the diode’s equivalent circuit.
A. Ideal model
B. Simplified model
C. Piecewise linear model
D. Real model

12. There are two mechanisms by which holes and electrons move through a silicon crystal. They are
A. Covalent bond and recombination
B. Diffusion and drift
C. Free and charge particles
D. Forward and reverse bias

13. A semiconductor is an element with a valence of
A. Four
B. Eight
C. Two
D. One

14. What orbit controls the electrical property of the atom?
A. Valence orbit
B. First orbit
C. Fourth orbit
D. M shell

15. ________ is a substance that contains atoms with several bands of electrons but with only one valence electron.
A. Insulator
B. Conductor
C. Semiconductor
D. Resistor

16. Pure silicon crystal atoms contain how may valence electrons as a result of covalent bonding?
A. 1
B. 4
C. 8
D. 16

17. The peak inverse voltage of a full wave center tapped rectifier circuit is equal to _______ of the input signal.
A. Thrice the peak
B. Twice the peak
C. One half
D. One third

18. Diffusion or storage capacitance is the term used to refer to
A. The reverse bias capacitance of a diode
B. The forward bias capacitance of a diode
C. The breakdown capacitance of a zener diode
D. The effective capacitance of the rectifier

19. What is considered as the key electrical conductivity?
A. The number of electrons in the valence orbit
B. The number of protons in the nucleus
C. The number of neutrons in the nucleus
D. The number of protons plus the number of electrons in the atom

20. Each atom in the silicon crystal has how many electrons in its valence orbit?
A. 8
B. 32
C. 2
D. 4

21. Lifetime is the amount of time between the creation and disappearance of a/an
A. Free electron
B. Proton
C. Ion
D. Neutron

22. A silicon crystal is an intrinsic semiconductor
A. If every atom in the crystal is a silicon atom
B. If majority of the atoms in crystal is a silicon atom
C. If the crystal contains 14 silicon atoms
D. If  the crystal is undoped

23. At room temperature, a silicon crystal acts approximately like a/an
A. Insulator
B. Semiconductor
C. Conductor
D. Superconductor

24. An extrinsic semiconductor is a
A. Doped semiconductor
B. Pure semiconductor
C. Good insulator
D. Good conductor

25. What is associated with random motion due to thermal agitation in the movement of holes and electrons in a silicon crystal?
A. Drift
B. Diffusion
C. Doping
D. Recombination

26. The peak inverse voltage of a half wave rectifier circuit is approximately equal to the ________ of the input signal.
A. Peak amplitude
B. Frequency
C. Voltage sinusoidal
D. Current

27. Silicon that has been doped with a trivalent impurity is called a/an
A. P-type semiconductor
B. N-type semiconductor
C. Intrinsic semiconductor
D. Extrinsic semiconductor

28. Silicon that has been doped with a pentavalent impurity is called a/an
A. N-type semiconductor
B. P-type semiconductor
C. Intrinsic semiconductor
D. Extrinsic semiconductor

29. What is another name for a pn crystal
A. Junction diode
B. PN junction
C. Diode
D. Lattice

30. An acceptor atom is also called
A. Pentavalent atom
B. Trivalent atom
C. Minority carrier
D. Majority carrier

31. Which is a donor atom?
A. Trivalent atom
B. Aluminum
C. Boron
D. Pentavalent atom

32. In an n-type semiconductor, free electrons are called
A. Minority carriers
B. Valence electrons
C. Majority carriers
D. Charge carriers

33. in an n-type semiconductor, holes are called
A. minority carriers
B. majority carriers
C. protons
D. charge carriers

34. What is the barrier potential of germanium at 25˚C
A. 0.7 V
B. 0.3 V
C. 0.5 V
D. 0.4 V

35. The barrier potential for a silicon diode at 25˚C is approximately
A. 0.4 V
B. 0.3 V
C. 0.7 V
D. 0.5 V

36. Each pair of positive and negative ions at the junction is called a/an
A. Anion
B. Positron
C. Cation
D. Dipole

37. When temperature increases, barrier potential ________
A. Remains the same
B. Decreases
C. Increases
D. Either increases or decreases depending on the semiconductor material used

38. Avalanche effects occurs at
A. Higher reverse voltages
B. Lower reverse voltages
C. Higher forward voltages
D. Lower forward voltages

39. The creation of free electrons through zener effect is also known as
A. Avalanche emission
B. Thermionic emission
C. Low-field emission
D. High-field emission

40. Zener effect only depends on the
A. High-speed minority carriers
B. High-speed majority carriers
C. Intensity of the electric field
D. Intensity of the magnetic field

41. What temperature is inside the diode, right at the junction of the p and n-type materials?
A. Junction temperature
B. Ambient temperature
C. Internal temperature
D. Absolute temperature

42. What is the input control parameter of a FET?
A. Gate voltage
B. Source voltage
C. Drain voltage
D. Gate current

43. One of the important diode parameters which gives the magnitude of current the diode candle without burning.
A. Reverse saturation current
B. Reverse current
C. Forward current
D. Forward breakdown current

44. The maximum reverse voltage that can be applied before current surges is called
A. Reverse recovery time
B. Maximum junction voltage
C. Forward voltage
D. Reverse breakdown voltage

45. What is the other name of Esaki diode?
A. Diac
B. Hot-carrier diode
C. Shockley diode
D. Tunnel diode

46. The most important application of schottky diodes is in
A. Digital computers
B. Power supplies
C. Amplifier circuits
D. Voltage regulators

47. A diode is a nonlinear device because
A. It produces a nonlinear graph
B. Its current is not directly proportional to its voltage
C. It has a built-in barrier potential
D. It can rectify alternating current

48. The sum of the resistance of the p-region and the n-region is called
A. Junction resistance
B. Extrinsic resistance
C. Intrinsic resistance
D. Bulk resistance

49. What is the typical bulk resistance of rectifier diodes?
A. Less than 1Ω
B. Greater than 1Ω
C. Equal to 1Ω
D. It depends on the doping level

50. The reverse bias diode capacitance is termed as
A. Transition region capacitance
B. Diffusion capacitance
C. Storage capacitance
D. Reverse capacitance 