This is 100 items set of Practice Examination 5 in Electronics Engineering composed of previous Board Exams Questions. Read each questions and choices carefully! Choose the best answer. In the actual board, you have to answer 100 items in Electronics Engineering within 5 hours. You have to get at least 70% to pass the subject. Electronics Engineering is 30% of the total 100% Board Rating along with Mathematics (20%), General Engineering and Applied Sciences (20%) and Electronics Systems and Technology (30%).
Start the Test Yourself Exam 5
Choose the letter of the best answer in each questions.
1. According to the classical Bohr model, the ________ is viewed as having a planetary-type structure.
- A. atom
- B. proton
- C. electron
- D. neutron
2. An n-type semi-conductive material is created by adding impurity atoms that have ________ valence electrons.
- A. 2
- B. 4
- C. 3
- D. 5
3. What composes an atom?
- A. One nucleus and only one electron
- B. Protons, electrons, and nucleus
- C. One nucleus and only one proton
- D. Electrons and protons only
4. What is nucleus of an atom?
- A. It is made up of protons and neutrons.
- B. Only protons are there.
- C. Protons and electrons are within the nucleus.
- D. It is composed only of neutrons.
5. What is the atomic number of silicon?
- A. 29
- B. 34
- C. 14
- D. 15
6. What is the atomic number of germanium?
- A. 29
- B. 34
- C. 32
- D. 15
7. What is the letter designation of the valence shell in a silicon atom?
- A. M
- B. N
- C. O
- D. L
8. Where are valence electrons found?
- A. In the closest orbit to the nucleus
- B. In various orbits around the nucleus
- C. In the most distant orbit from the nucleus
- D. In the nucleus of an atom
9. How is positive ion formed?
- A. When a valence electron breaks away from the atom
- B. When there are more holes than electrons in the outer orbit
- C. When the two atoms bond together
- D. When an atom gains an extra valence electron
10. How is negative ion formed?
- A. When a valence electron breaks away from the atom
- B. When there are more holes than electrons in the outer orbit
- C. When the two atoms bond together
- D. When an atom gains an extra valence electron
11. What is the most widely used semiconductor material in electronic devices?
- A. Germanium
- B. Silicon
- C. Gallium
- D. Arsenic
12. What energy band in which free electrons exists?
- A. Valence band
- B. Conduction band
- C. First band
- D. Second band
13. How are electron-hole pairs produced?
- A. By recombination
- B. By thermal energy
- C. By ionization
- D. By doping
14. When an electron falls into a hole this is
- A. recombination
- B. ionization
- C. avalanche breakdown
- D. doping
15. What hold together the atoms in a semiconductor crystal?
- A. By covalent bonding
- B. By forces of attraction
- C. By the interaction of valence electrons
- D. All of the choices
16. In a silicon crystal, each atom has
- A. four conduction electrons
- B. eight valence electrons, four of its own and four shared
- C. four valence electrons
- D. no valence electrons
17. What produces the current in a semiconductor?
- A. The electrons only.
- B. The holes only.
- C. Negative ions only.
- D. By both electrons and holes.
18. In an intrinsic semiconductor,
- A. the free electrons are thermally produced.
- B. there are as many free electrons as there are holes.
- C. there are no free electrons.
- D. Both A and B above.
19. What is the difference between semiconductor and an insulator?
- A. The atomic structure.
- B. The number of free electrons.
- C. A wider energy gap between the valence band and the conduction band.
- D. All of the choices.
20. What is the process of adding impurity to an intrinsic semiconductor?
- A. Doping
- B. Recombination
- C. Ionization
- D. Annihilation
21. What impurity is added to silicon to create a p-type semiconductor?
- A. Trivalent
- B. Pentavalent
- C. Intrinsic
- D. Extrinsic
22. What is the purpose of a pentavalent impurity?
- A. To reduce the conductivity of silicon
- B. To increase the number of holes
- C. To create minority carriers
- D. To increase number of free electrons
23. What are the majority carriers in an n-type semiconductor?
- A. Valence electrons
- B. Conduction electrons
- C. Protons
- D. Holes
24. What are holes in n-type semiconductor?
- A. Majority carriers that are thermally produced.
- B. Minority carriers that are thermally produced.
- C. Majority carriers that are produced by doping.
- D. Minority carriers that are produced by doping.
25. How is pn junction formed?
- A. By the boundary of p-type and n-type material
- B. By ionization
- C. By collision of proton and neutron in the nucleus
- D. By the recombination process
26. What creates the depletion region?
- A. Ionization
- B. Diffusion
- C. Recombination
- D. All of the choices
27. What are in the depletion region?
- A. Positive and negative ions
- B. Minority carriers
- C. Majority carriers
- D. All of the choices
28. What does the term bias mean?
- A. The amount of current across the junction.
- B. The ratio of majority to minority carriers.
- C. The dc voltage applied to control the operation of the devices.
- D. All of the choice
29. How to forward bias a pn junction diode?
- A. By applying an external voltage that is positive to the anode and negative to the cathode
- B. By applying an external voltage that is positive at the p-region and negative at the n-region
- C. By applying an external voltage that is negative at the anode and positive to the cathode.
- D. Either A and B above.
30. What happens when the pn junction is forward-biased?
- A. The current is produced by both holes and electrons
- B. Hole current is the only current
- C. Electron current is only the current.
- D. Majority carriers produced the only current.
31. What causes a very small current in reversed-bias condition?
- A. Majority carriers
- B. Minority carriers
- C. Forward current
- D. Reverse current
32. What is typically the forward-bias voltage for a silicon diode?
- A. Greater than 0.7 V
- B. Lesser than 0.7 V
- C. Greater than 0.3 V.
- D. Lesser than 0.3 V
33. When does a diode conduct current?
- A. When applied with a voltage
- B. When forward-biased
- C. When reverse-biased
- D. When power is on
34. What voltage is read by the voltmeter when connected across a forward-biased diode?
- A. The diode barrier potential
- B. The bias battery voltage
- C. The total circuit voltage
- D. 0 V
35. If the positive lead of an ohmmeter is connected to the anode of a diode and the negative lead to the cathode then the diode is
- A. reversed-biased
- B. opened
- C. shorted
- D. forward-biased
36. What is the ideal dc output of a capacitor filter?
- A. Equal to the rms value of the rectified voltage
- B. Equal to the average value of the rectified voltage
- C. Equal to the peak value of the rectified voltage
- D. Equal to the peak-to-peak value of the input voltage
37. If the load resistance of a capacitor-filtered full-wave rectifier is reduced, the ripple voltage
- A. increases
- B. decreases
- C. has a different frequency
- D. is not affected
38. What is the output of full-wave bridge-type rectifier when one of the diodes opens?
- A. 0 V
- B. A half-wave rectified voltage
- C. A 120-Hz voltage
- D. One fourth the amplitude of the input voltage
39. A virtual ground is a ground for
- A. voltage but not for current
- B. current but not for voltage
- C. both current and voltage
- D. neither current nor voltage
40. Normally in a zener voltage regulator the cathode is
- A. more negative than the anode
- B. more positive than the anode
- C. at +0.7 V
- D. grounded
41. What determines line regulation?
- A. The load resistance
- B. The load current
- C. The changes in load resistance and output voltage
- D. The changes in the output voltage and input voltage
42. What determines load regulation?
- A. The changes in load current and input voltage
- B. The changes in load current and output voltage
- C. The changes in load resistance and input voltage
- D. The changes in zener current and load current
43. What is a no-load condition?
- A. The load has infinite resistance.
- B. The load has zero resistance.
- C. The output terminals are open.
- D. Both A and C.
44. What is the maximum efficiency of a full-wave rectifier?
- A. 40.6%
- B. 20.3%
- C. 90%
- D. 81.2%
45. The dc output of the bridge type rectifier is nearly _________ than that of center tap circuit for a given transformer.
- A. thrice
- B. twice
- C. four times
- D. three times
46. In a center-tap circuit, __________ transformer secondary voltage is utilized.
- A. one-half
- B. full
- C. one-third
- D. one-eight
47. What is the maximum efficiency of a half-wave rectifier?
- A. 20.3%
- B. 80.6%
- C. 50%
- D. 40.6%
48. What rectifier circuit in which a transformer is essential?
- A. Bridge type
- B. Half-wave
- C. Center-tap
- D. Full-wave
49. In a full-wave rectifier, if ac supply is 50 Hz, then what is the ac ripple in the output?
- A. 50 Hz
- B. 100 Hz
- C. 25 Hz
- D. 200 Hz
50. How many diodes are used by a bridge type rectifier?
- A. Two
- B. Four
- C. Three
- D. Five
51. For the same dc output, center-tap circuit should have _________ PIV as compare to bridge type circuit.
- A. same
- B. smaller
- C. higher
- D. not comparable
52. What rectifier is used for high voltage applications?
- A. Center-tap
- B. Bridge type
- C. Half-wave
- D. Full-wave
53. What filter is generally employed in the power supply of a radio receiver?
- A. Choke filter
- B. Capacitor input
- C. Resistance
- D. Inductor input
54. What capacitor is generally used in filter circuits?
- A. Mica
- B. Paper
- C. Air
- D. Electrolytic
55. In a half-wave rectifier, if ac supply is 50 Hz, then what is the ac ripple?
- A. 100 Hz
- B. 50 Hz
- C. 25 Hz
- D. 12.5 Hz
56. The dc output of a bridge type circuit is _________ that equivalent center-tap circuit.
- A. the same as
- B. more than
- C. less than
- D. smaller
57. The values of L and C in filter circuits for a half-wave rectifier are ________ as compared to that of full-wave rectifier.
- A. same
- B. more
- C. less
- D. not related
58. What is provided by transformer coupling?
- A. Impedance matching
- B. Good frequency response
- C. Step-up in voltage
- D. Simplicity and economy
59. Germanium photodiodes have dark currents typically of the order of _______mA.
- A. 10
- B. 15
- C. 20
- D. 25
60. How many filaments are there for a mercury vapor discharge tube for domestic lighting?
- A. 2
- B. 3
- C. 4
- D. 5
61. What is the typical value of slew rate of an operational amplifier?
- A. 1 V/μs
- B. 2 V/μs
- C. 3 V/μs
- D. 4 V/μs
62. What is the typical frequency range about the center frequency of a tunable magnetron?
- A. ± 1%
- B. ± 3%
- C. ± 4%
- D. ± 5%
63. The largest computers commonly use a word size of how many bits?
- A. 32
- B. 64
- C. 128
- D. 256
64. What is the maximum number of degrees of freedom of any solid object?
- A. 3
- B. 4
- C. 5
- D. 6
65. A microprocessor can communicate with other devices in the system of _______ buses.
- A. 2
- B. 3
- C. 4
- D. 5
66. The repeatability of a servo-controlled robot is within __________ mm rather than a fraction of a mm.
- A. 1
- B. 2
- C. 3
- D. 4
67. The Kuka spot welding robot has how any degrees of freedom?
- A. 2
- B. 3
- C. 4
- D. 6
68. A negative resistance region evidenced in the Ep-Ip characteristic of a tetrode when dc screen voltage exceeds dc plate voltage. The negative slope of the plate current curve is due to the screens attractive secondary electrons from the plate when screen voltage exceeds plate voltage and the attendant reduction of plate current during the interval. What effect is mentioned above?
- A. Tetrode effect
- B. Magnetron effect
- C. Compton effect
- D. Dynatron effect
69. The reception and reproduction of radio signals by ordinary pieces of metal in contact with each other, such as sections of stovepipes. This occurs when rusty bolts, faulty welds, or mechanically loose connections within strong radiated fields near transmitter and produce intermodulation interference. The mechanically poor connections serve as nonlinear diodes. What effect is mentioned above?
- A. Singing-stovepipe effect
- B. Dynatron effect
- C. Compton effect
- D. Malter effect
70. The elastic scattering of photons by electron. Since the total energy and total momentum are conserved in the collisions, the wavelength of the scattered radiation is changed by an amount that depends on the angle of scattering, and part of the photon energy is transferred to electrons. This effect is called
- A. Compton effect
- B. Hall effect
- C. Malter effect
- D. Thomson effect
71. The generation of acoustic waves, consisting of alternate regions of compression and refraction one half-wavelength apart, by a piezoelectric crystal vibrating in a longitudinal mode in a liquid. When a parallel beam of light sent through the liquid in a tank having plate-glass walls, the acoustic waves act as a diffraction grating that can be used to determine the velocity of sound in the liquid. This effect is called
- A. Damon effect
- B. Debye-Sears effect
- C. Thomson effect
- D. Malter effect
72. When light falls on a light surface of an intermetallic semiconductor located in a magnetic field that is parallel to the surface, excess hole electron pairs are created. Those carriers diffuse in the direction of the light but are deflected by the magnetic field to give a current flow through the semiconductor that is at right angles to both the light rays and magnetic field. This is known as the
- A. Photoelectromagnetic effect
- B. Conductive effect
- C. Photo effect
- D. Light effect
73. What determines the identity of an element?
- A. The number of protons in the nucleus
- B. The number of electrons in the orbit
- C. The number of neutrons in the nucleus
- D. The atomic mass
74. Who coined the term hypertext?
- A. Ted Nelson
- B. Tim Berners-Lee
- C. Larry Roberts
- D. Vannevar Bush
75. Who is known as the Father of the ARPANET?
- A. Ted Nelson
- B. Tim Berners-Lee
- C. Larry Roberts
- D. Vannevar Bush
76. Who coined the term nanotechnology?
- A. Norio Taniguchi
- B. Aibo Nintendo
- C. Yakura Tamaguchi
- D. Sato Mikado
77. What do you call waves of electrons traveling along the surface of metals?
- A. Plasmons
- B. Isotopes
- C. Nucleons
- D. Nanomons
78. Who invented Ethernet?
- A. Bob Metcalfe
- B. Douglas Engelbart
- C. Tim Berners-Lee
- D. Larry Roberts
79. Who is the inventor of the mouse?
- A. Bob Metcalfe
- B. Douglas Engelbart
- C. Tim Berners-Lee
- D. Larry Roberts
80. Who developed the internet browser called Mosaic?
- A. Marc Andreesen
- B. Paul Baran
- C. Larry Roberts
- D. Bob Metcalfe
81. Who created the World Wide Web?
- A. Bob Metcalfe
- B. Douglas Engelbart
- C. Tim Berners-Lee
- D. Larry Roberts
82. Who wrote the Transmission Control Protocol (TCP) for internet?
- A. Vinton Cerf
- B. Bob Khan
- C. Tim Berners-Lee
- D. Both A and B
83. Who wrote the Hypertext Transfer Protocol (HTTP), the language computer could use to communicate hypertext documents over the internet?
- A. Vinton Cerf
- B. Bob Khan
- C. Tim Berners-Lee
- D. Larry Roberts
84. What effect refers to a leakage current that flow over a surface path between the collector and emitter in some types of transistors?
- A. Channel effect
- B. Collector follower effect
- C. Leakage effect
- D. Emitter effect
85. An effect about the change that the susceptibility of a ferrite undergoes under the influence of high RF powder.
- A. Change effect
- B. Damon effect
- C. Dead-end effect
- D. Barnett effect
86. An outward-curving distortion of lines of force near the edges of two parallel metal plates that form a capacitor.
- A. Change effect
- B. Edge effect
- C. Dead-end effect
- D. Skin effect
87. The extension of the electrostatic field of an air capacitor outside the space between its plates.
- A. Fringe effect
- B. Edge effect
- C. Extension effect
- D. Flywheel effect
88. The sudden, large increase in current that occurs when a particular value of reverse voltage is reached, and which is due to ionization by the high intensity electric field in the depletion region in reverse-biased pn junction.
- A. Zener effect
- B. Avalanche effect
- C. Radiation effect
- D. Burst effect
89. The liberation or absorption of heat when an electric current flows from a warmer to a cooler part of a conductor.
- A. Zener effect
- B. Skin effect
- C. Surface effect
- D. Thomson effect
90. The piercing of a barrier in a semiconductor by a particle that does not have sufficient energy to go over the barrier.
- A. Channel effect
- B. Damon effect
- C. Tunnel effect
- D. Barrier effect
91. The development of a voltage across the junction of two dissimilar materials.
- A. Photovoltaic effect
- B. Hall effect
- C. Piezoelectric effect
- D. Flywheel effect
92. The increase in the effective grid-cathode capacitance of a vacuum tube due to the charge induced electrostatically on the grid by the anode through the grid-anode capacitance.
- A. Hall effect
- B. Barnett effect
- C. Damon effect
- D. Miller effect
93. The development of a voltage between the two edges of a current-carrying metal strip whose faces are perpendicular to a magnetic field.
- A. Hall effect
- B. Barnett effect
- C. Miller effect
- D. Damon effect
94. A magnetic field when applied to a right angles to the direction of a temperature gradient in a conductor, a temperature difference is produced at right angles both to the direction of temperature gradient and the direction of the magnetic field.
- A. Hallwachs effect
- B. Island effect
- C. Isotope effect
- D. Leduc effect
95. The ability of a resonant circuit to maintain oscillation at an essentially constant frequency when fed with short pulses of energy at constant frequency and phase.
- A. Flywheel effect
- B. Leduc effect
- C. Hall effect
- D. Thomson
96. The development of a DC voltage between two regions of a photoconductive semiconductor when one of the regions is illuminated by diffusion of an optically generated hole and electron pairs away from the illuminated region.
- A. Destriau effect
- B. Isotope effect
- C. Dember effect
- D. Hawks effect
97. Phenomenon of a current flowing between two unequal illuminated electrodes of a certain type when they are immersed in an electrolyte.
- A. Bequerel effect
- B. Destriau effect
- C. Dember effect
- D. Hawks effect
98. The restriction of emission from the cathode of an electron tube to a certain small areas of the cathode when the grid voltage is lower than a certain value.
- A. Island effect
- B. Isotope effect
- C. Damon effect
- D. Hawks effect
99. The tendency for layer of semiconductor having a high secondary emission ratio to become positively charged when bombarded by electrons. This occurs when a thin insulator separates the semiconductor from the metal plates. The insulator must be very thin on the order of 10^-7 meters. This results in a potential difference of up to about 100 volts.
- A. Mateucci effect
- B. Malter effect
- C. Destriau effect
- D. Hall effect
100. The magnetic force between adjacent current-carrying conductors is referred to as
- A. motor effect
- B. edge effect
- C. proximity effect
- D. generator effect
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