ECE Board Exam:April 2005:Electronics 1.
The main purpose of an instrumentation amplifier is _____. a. To compare input signals. b. To amplify small signals that are riding on large common mode voltages. c. To reject unwanted signals. d. To trim small signals that are riding on large common mode voltages.
2.
In a series RLC circuit, what is the condition of the circuit if there is high impedance, low current, and low reactance voltages? a. Ideal circuit b. Percent circuit c. Resonant d. Non-resonant
3.
The most accurate type of test equipment used for measuring high power is the _____. a. Bolometer b. Wavemeter c. Calorimeter d. Wattmeter
4.
The effect on the human body of 21-20 mill-amperes, 60 Hz A.C. or 80-?? milliamperes D.C is ______. a. Respiratory failure b. Mascular inhibition c. Reflex action d. Surprise
5.
A straight line plot of collector current Ic and Vce for a transistor circuit is called the _____. a. Threshold line b. DC loadline c. Loading limit d. Linear level
6.
If a transformer has a turns ratio of 1:3, what is the current ratio? a. 1:3 b. 1:9 c. 3:1 d. 9:1
7.
There is a _____ degrees of inversion between gate and drain voltages of an FET. a. Zero b. 90
c. 180 d. 270 8.
A differential circuit uses a _____. a. Capacitor in its feedback circuit b. RLC in its feedback circuit c. Inductor in its feedback circuit d. Resistor in its feedback circuit.
9.
Which of the following shells contain 2 electrons? a. L b. N c. M d. K
10. a. b. c. d.
What amplifier is used when power from a convertion servoamplifier is too small to drive large servomotors (either A.C or D.C.)? Differential amplifier RD amplifier Audio amplifier Operational amplifier 11.
An amplifier which is designed to be used with other circuit component to perform either computing functions or some type of transfer operation? a. Differential amplifier b. RD Amplifier c. Audio amplifier d. Operational amplifier
12.
What type of LC oscillator is sometimes called a “tickler” oscillator in reference to the transformer secondary or tickler coil that provides the feedback to keep the oscillator going? a. Colpitts b. Clapp c. Armstrong d. Hartley
13.
The ratio of the DC collector current Ic to the emitter current Ie is called the DC ______. a. Delta b. Beta (Bdc) c. Echo d. Alpha (Adc)
14.
The effect of 60 Hz A.C. over 100 mA or DC over 300 mA on the human body. a. Mascular inhibition
b. Respiratory failure c. Surprise d. Usually fatal 15.
The bit storage capacity of a Read Only Memory(ROM) with a 512 x 8 organization is _____ bits. a. 1024 b. 8192 c. 4096 d. 2048
16.
The device used to produce a gradual chance of impedance at the end of a waveguide is called a _____. a. Funnel b. Load c. Dummy d. Horn
17.
In a robots, he axis that allows rotation are often referred to as _____ joints a. Revolving b. Revolute c. Resolute d. Rotary
18.
The most widely used combination bias system in basic transistor amplifier a. Limited type b. Current divider type c. Voltage-divider type d. Base current type
19.
The open-loop gain of an op-amp is given at 225,000. Find the gain in dB. a. 1070 b. 107 c. 214 d. 10.7
20.
A _____ is a solid material formed by atoms bonding together in a fixed pattern. a. Block b. Crystal c. Lattice d. Pyramid
21.
Elements with 5 or more valence electrons are called _____. a. Semi-conductors b. Conductors c. Molecule
d. Insulators 22.
When the resistance of the load is high with respect to the resistance of the source _____ in a circuit is achieved. a. Maximum power b. High efficiency c. Maximum transfer d. High voltage
23.
As the input voltage varies within specified limits, the zener diode maintains a nearly constant output voltage across its terminal. This is called _____. a. Auto regulation b. Specific regulation c. Line regulation d. Load regulation
24.
The method of assigning more sectors to the outer disk tracks is referred to as _____ recording. a. Random b. Zone c. Sector d. System
25.
_____ is the unit of electrical current flow. a. Volt b. Ohm c. Amepere d. Watt
26.
According to Ohm’s Law, what happens to the circuit current if the circuit resistance increases? a. Current double b. Current decreases c. Current increases d. Current remains constant
27.
Determine the open loop gain of an Op-am whose cur-off frequency is 100 Hz with a midrange voltage gain of 100,000. a. 7,071 b. 707.1 c. 70,710 d. 70.71
28.
DC biasing is used to establish a steady level of transistor current. This is called the _____. a. Operating coordinates
b. Threshold point c. Range of operation d. DC operating point 29.
Arc blow can be avoided in electrical welding by _____ a. Increasing arc length b. Welding away from the earth ground connection c. Using bare electrodes d. Using AC welding machines
30.
The distance covered or traveled by a waveform during the time interval of one complete cycle. a. Frequency b. Wavelength c. Time slot d. Wave time
31.
_____ is the non-linear distortion characterized by the appearance (at the system output)_ of frequencies equal to the sums or difference of two or more frequencies at the input. a. Differential distortion b. Inter modulation distortion c. Mutual distortion d. Modulated distortion
32.
Find the phase angle between the voltage across and the current through the circuit when Xc is 25 ohms, R 100 ohms and Xl is 50 ohms. a. 76 degrees with the voltage leading the current b. 14 degrees with the voltage lagging the current c. 14 degrees with the voltage leading the current d. 76 degrees with the voltage lagging the current
33.
If the resistance of a circuit is doubled and the applied voltage is kept constant, the current will _____. a. Be quadrupled b. Remain the same c. Be cut in half d. Be doubled
34.
To produce tin film resistors, which of the following materials is the most widely used? a. Titanium b. Tantalum c. Nichrome d. Chromium cermets
35.
Which of the following are techniques used to eliminate bonding wire and to improve packaging in IC production? a. Flip chips b. Beam lead chips c. Flat pack d. DIP i. A,B, and C only ii. A and C only iii. A and B only iv. A,B,C, and D
36.
List the two advantages of a voltage divider in DC biasing a. Unstable, uses two supply voltages b. Unstable, uses one supply voltage c. Stable, uses one supply voltages d. Stable, uses two supply voltages
37.
_____ is a kind of oscilloscope which consist of narrowband if filter and a local oscillator (receiver) capable of showing transmitter carriers, spacing, harmonics and sidebands. a. Polygraph b. Harmonics analyzer c. Spectrum analyzer d. Computerized tomography
38.
One cycle is equal to how many degrees of rotation of a conductor in a magnetic field? a. 270 b. 360 c. 180 d. 90
39.
A measuring device which will result to full scale reading at shorted terminal condition a. Voltmeter b. Ammeter c. Electrostatic meter d. Ohmmeter
40.
which of the following are the buses for information transfer internally and externally in a microprocessor a. address bus b. data bus c. control bus i. A and C only ii. A and B only
iii. B and C only iv. A, B, and C only 41.
If the voltage gain for each input of a summing amplifier with a 4.8 kilo-ohm feedback resistor is unity, the input resistors must have a value of _____ kilo-ohm. a. 4.8 times the number of inputs b. 48 c. 4.8 divided by the number of inputs d. 4.8
42.
To match the waveguide to the load, _____ devices are placed in the waveguide. a. Standing wave b. Resistive c. Metal plate d. Impedance changing
43.
What is system? a. b. c. d.
the generic term for utilities and programs needed to operate a computer Hardware Software People water Tupper ware
44.
The computer worm that infected computer systems world-wide in 10 minutes, making it the fastest computer virus ever known is called _____. a. Claw Hammer b. Sledge Hammer c. SQL Hammer d. SARS Virus
45.
The channel of JFET is between the _____. a. Input and output b. Drain and source c. Gate and drain d. Gate and source
46.
What is the common use of a push-pull amplifier? a. AN OPAM b. A driver c. Wideband amplifier d. A coupler
47.
For a bipolar junction transition(eto tlga yung nakalagay) (BJT) to operate properly, the base-collector junction should be _____ biased. a. Positive b. Forward
c. Negative d. Reverse 48.
Large centralized data-processing complexes like multi-national companies, departments and corporations use which type of general-purpose computer that operates programs simultaneously? a. Mini-computer b. Micro0computer c. Main-frame computer d. Super-computer
49.
In parallel resonant LC circuit, what is the impedance at resonant frequency? a. Zero b. The maximum impedance value c. Infinity d. Determined solely by the dc resistance
50.
The area in which the axis motion of a robot manipulator can operate without any obstruction is called the e_____. a. Work area b. Range of operation c. Range of motion d. Work envelope
51.
The BEST choice electronic device to turn a device at a particular voltage is a/an _____. a. SCR b. SCS c. DIAC d. PUT
52.
What term is used to describe the ability a system to distinguish between targets that are close together? a. Radar sensitivity b. Target designation c. Radar agility d. target resolution
53.
What do you call a concept which describes the relationship of all functional components of a computer such as CPU and input./output devices? a. Engineering development b. Architecture c. Prototyping d. Pre-production modeling
54.
The use of feedback to achieve the desired response of a dynamic system in the presence of uncertainties, disturbance or constraints is called _____. a. Synchronization b. Response c. Control d. Servomechanism
55.
The primary purpose of a voltage regulator is to provide an output voltage with little or no _____. a. Figure of merit b. Value c. Regulation d. Variation
56.
Displays files in specified directory and all subdirectories a. Solid b. Doped c. Intrinsic d. Extrinsic
57.
In waveguide theory, what causes the current-carrying area at the center conductor of the coaxial line to be restricted to a small layer at the surface? a. Dielectric losses b. Standing wave c. Skin effect d. Copper losses
58.
This peak current specified for a given number of cycles or portion of a cycle. a. Surge current b. Maximum current c. Peak surge current d. High current
59.
An electron moves into the electrostatic field between a positive charge and a negative charge. Toward which charge will the electron move? a. Outwards b. The negative charge c. The center d. The positive charge
60.
_____ is the definite discrete amount of energy required to move an electron from a lower shell to a higher shell a. Quantum b. Positive energy c. The center d. The positive charge
61.
Which of the following are the basic measurements? a. Voltage b. Current c. Resistance d. Capacitance and conductance i. Neither (a and b) nor (c, d, and e) ii. A, b, c, d , and e iii. C, d, and e only iv. A and b only
62.
Monolithic integrated circuits are usually referred to as _____. a. Selenium rectifiers b. ?? (ndi ko na mabasa) c. Silicon chips d. Hybrids
63.
_____ is an intermodulation condition that occurs when a carrier modulates by an undesired signal. a. Short modulation b. Cross modulation c. Under modulation d. Over modulation
64.
In microwave tubes, what is the basic principle of operations of a klystron? a. Strong electrostatic field b. Energy transfer and amplification c. Oscillation d. Velocity modulation
65.
An English scientist who drew up plans for the first programmable computer in 1830 a. Vannevar bush b. William oughtred c. Charles Babbage d. Herman hollerith
66.
In an optical coupler, this parameter is the ratio of the output current to the input current through the LED, expressed in percentage. What is this ratio? a. DC current coupling ratio b. AC current transfer ratio c. AC current coupling ratio d. DC current transfer ratio
67.
_____ refers to the difference between the carrier frequencies of an FM signal and the instantaneous frequency of its modulated wave.
a. b. c. d.
Differential frequency Frequency deviation Modulated frequency Frequency band
68.
The most widely used abrasive is _____. a. Tungsten b. Graphite c. Silicon carbide d. Alumina
69.
The most common bias circuit providing Q-point stability with a single polarity supply voltage is what type bias circuit a. Collector feedback b. Voltage divider c. Emitter d. Base
70.
What happens to the portion of the wave front that do not satisfy the boundary conditions, when a wavefront is radiated into a waveguide? a. It collapses b. It decreases to zero c. It is reflected back d. It increases to maximum
71.
The schokeydiode(eto tlga yungnakalagay. Schokey diode) is a thyristor that conducts when the voltage across its terminal exceed the _____ potential. a. Trigger b. Breakover c. Operating d. Maximum
72.
The value of the drain-to-source voltage of a GFET at which the drain current becomes constant when the gate-to-source voltage is zero is called _____ voltage. a. Breakdown b. Cut off c. Threshold d. Pinch off
73.
Insulators are characterized by a _____ energy gap between its conduction bands an valence band. a. Very narrow b. Wide c. Very wide d. Narrow
74.
_____ is an electrical current that flows in one direction only. a. Normal current b. Alternating current c. Direct current d. Eddy current
75.
The input resistance at the gate of an FET is _____. a. Relatively low b. Zero c. Extremely high d. Average
76.
It is the generated in a D.C. motor as armature coils out the field flux opposes the applied voltage, and limits the flow of armature current. a. Electromotive force b. Field excitation c. Counter-electromotive force d. Armature excitation
77.
The person responsible for the researend(as is) design and development of a complete information system. a. PROGRAMMER b. PEOPLE WARE c. SYSTEM ANALYST d. COMPUTER OPERATOR
78.
In a robotic system, how many degrees of freedom can be given to a manipulator by adding a wrist? a. Four b. Six c. Three d. Two
79.
Term for energy that is stored in electromagnetic or electrostatic field. a. Amperes-joules b. Joules-coulombs c. Potential energy d. Kinetic energy
80.
What do you call the “Filter” between a corporate network and the internet that keeps the corporate network secure from intruders while giving corporate users unhibited access to the internet? a. Bandstep (as is) b. Bandpass c. Firewall d. Firestorm
81.
Which of the following circuit conditions requires circuit protection? a. Direct short/shot circuit b. Excessive heat c. Excessive current i. A and C only ii. A, B and C only iii. B and C only iv. A and B only
82.
Two basic categories of voltage regulators are a. Differential, integral b. Capacitive, inductive c. Linear switching d. Centrifugal, centripetal
83.
A measure of the energy absorbed from radiation by tissue or other biological material and is a equal to the transfer of 1 x 10-2 Joules energy per kilogram of material is called a _____. a. Radical b. Rad c. Radian d. Radius
84.
The type of feedback used to increase amplitude of output signal. a. Negative feedback b. Unwanted feedback c. Positive feedback d. Fidelity feedback
85.
A transistor constructed with three-doped semiconductor region separated by two pn junction is called a _____. a. Metal oxide semiconductor FET b. Field effect transistor c. Junction field effect transistor d. Bipolar junction transistor
86.
A type of filter that passes a narrow band of frequencies though a current and attenuates the desired band of frequencies that are high or lower than the desired band of frequencies. a. Low-pass filter b. Band-reject filter c. Band-pass filter d. High-pass filter
87.
Which of the following are circuit control devices?
a. Switches b. Solenoid c. Relays i. B and C only ii. A and B only iii. A, B, and C iv. A and C only 88.
What is an electric measuring equipment used in navigation which uses time measurement concept for a wave to travel from a place receiving station and back? a. Tacan b. OODR c. ILS d. DME
89.
In a stand alone supply of power the rationale of cells making in series is to _____. a. Increase current capacity b. Increase voltage output c. Decrease voltage output d. Decrease internal resistance
90.
_____ is the total number of magnetic lines of force in a magnetic field. a. Magnetic potential b. Magnetic flux c. Magnet flux intensity d. Flux density
91.
An electronic device that can be turned on and turned off by a gate pulse is called a _____. a. Bipolar junction transistor b. Silicon-controlled switch c. Silicon-controlledrectirifer d. Shockley diode
92.
Which of the following are categories of computer system software? a. Operating system (OS) b. Utility programs c. Languages translator i. A and B only ii. B and C only iii. A and C only iv. A, B, and C
93.
A hot-carrier diode is a diode that ____. a. Emits light when forward biased b. Switches very fast
c. Varies resistance with temperature d. Changes its capacitance with voltage 94.
Which of the following are UJT terminals? a. Emitter b. Base c. Base2 d. Gate i. B, C and D only ii. A, B, and C only iii. A, B and D only iv. All of the above
95.
An amplifier exhibits three critical frequencies in its low-frequency response a. None of these b. 167hertz c. 130 hertz d. 75 hertz
96.
The value of anode current below which the SCR switches from the forwardconduction region to the forward blocking region is called _____ current. a. Switching, Is b. Operation, Io c. Holding, Ih d. Forward blocking, Ibl (f)
97.
In a transformer, the principle of electromagnetic induction is also known as _____. a. Coupling action b. Transformation c. Matching action d. Transformer action
98.
The symbols 1, 2 and 3 through 9 are what type of numerals? a. Boolean b. Roman c. Binary d. Arabic
99.
Type of semiconductor diode varies its internal capacitance as the voltage applied to its terminals varies. a. A zener diode b. A varactor diode c. A silicon-controlled rectifier d. A tunnel diode
100. Which of the following are means of achieving tin films in IC manufacturing?
a. Thermal growth b. Chemical vapor deposition c. Evaporation i. A and C only ii. B and C only iii. A, B, and C iv. A and B only Answer key: (yung iba wla talagang sagot..) 1. B 2. D 3. C 4. B 5. B 6. C 7. C 8. D 9. D 10. B 11. D 12. C 13. D 14. D 15. C 16. D 17. A 18. C
19. B 20. B 21. D 22. D 23. C 24. C 25. C 26. B 27. C 28. D 29. D 30. B 31. B 32. C 33. C 34. C 35. C 36. C
37. C 38. B 39. D 40. D 41. D 42. D 43. B 44. C 45. B 46. B 47. D 48. C 49. B 50. D 51. C 52. D 53. B 54. C
55. D 56. ? 57. C 58. C 59. D 60. A 61. D 62. C 63. B 64. D 65. C 66. A 67. B 68. D 69. B 70. B 71. B 72. D 73. C 74. C 75. C 76. C 77. A
78. C 79. C 80. C 81. B 82. C 83. B 84. C 85. D 86. C 87. C 88. B 89. B 90. B 91. B 92. A 93. B 94. B 95. D 96. ? 97. D 98. D 99. B 100. ?
