PERCDC ECT Review ECT COACHING

Module 1
1. Each specific complex impedance value defined in the form R + jXL
A. corresponds to a specific point in the RL plane.
B. corresponds to a specific inductive reactance.
C. corresponds to a specific resistance.
D. All of the above are true. *

2. What is the significance of connecting loads in parallel?

A. it makes power consumption less
B. it provides greater efficiency
C. it increases the safety factor
D. it allows independent operations of loads *

3. In a two-source circuit, one source acting alone produces 12mA through a given
branch. The other source acting alone produces 10 mA in the opposite direction
through the same branch. The actual current through the branch is
A. 22 mA
B. 10 mA
C. 12 mA
D. 2 mA *

4. A rheostat is a device that regulates the strength of an electric current by

A. Increasing the magnetic field in the circuit
B. Varying the voltage in the circuit
C. Varying the resistance in the circuit *
D. Varying the current in the circuit

5. A magnetic coil produces 100,000 Maxwells with 2,000 turns and with a current
of 2 Amperes. The current is cut off and flux collapses in 0.01 sec. What is the
average voltage that will appear across the coil.
A. 20 kV
B. 200 V *
C. 2,000 kV
D. 2 kV

6. Electro-mechanical breakdown of solid insulating materials occurs due to

A. magnetic bum
B. vibrations
C. mechanical stresses produced by the electrical field *
D. electrical stresses produced by the voltage fluctuations

7. The rating of fuse wire is expressed in terms of

A. Ohms
PERCDC ECT Review ECT COACHING
B. Amperes *
C. Mhos
D. Watts

8. Electromagnet whose core is in the form of a close magnetic ring

A. solenoid
B. relay
C. toroid *
D. circular

9. A combination of two charges, with equal charge magnitude but opposite signs.
A. magnetic dipole
B. static dipole
C. dynamic dipole
D. electric dipole *

10. As an inductor core material, air:

A. Has excellent efficiency. *
B. Has high permeability.
C. Allows large inductance in a small volume.
D. Has permeability that can vary over a wide range.

11. If a coil is wound in layers, its inductance will be greater than that of a
similar single-layer coil because of a higher
A. permeability
B. flux linkage *
C. reluctance
D. conductance

12. Movement of holes in a semiconductor:

A. Is like a flow of electrons in the same direction.
B. Is possible only if the current is high enough.
C. Results in a certain amount of electric current.*
D. Causes the material to stop conducting.

13. A copper wire of unknown length has a resistance of 0.80 ohm. By successive
passes through drawing dies, the length of the wire is increased to 2½ times its
original value. Assuming that resistivity remains unchanged during the drawing
process, determine the new value of its resistance.
A. 4Ω
B. 3Ω
C. 5Ω *
D. 6Ω
PERCDC ECT Review ECT COACHING

14. A transistor can be protected from needless overheating by

A. a current-limiting resistor. *
B. bleeder resistors.
C. maximizing the drive.
D. shorting out the power supply when the circuit is off.

15. The current flowing through an unloaded voltage divider is called the:
A. resistor current
B. load current
C. bleeder current *
D. voltage current

16. The net amount of electric charge produced in any process is zero?
A. Coulomb’s first law
B. Coulomb’s second law
C. Gauss’ Law
D. Law of conservation of electric charge*

17. When the pointer of an analog ohmmeter reads close to zero, the resistor
being measured is
A. overheated
B. shorted *
C. open
D. reversed

18. What is the law whereby the force of attraction and repulsion between poles
is inversely proportional to the square of the distance between them?
A. Newton’s first law
B. Newton’s second law
C. Coulomb’s first law
D. Coulomb’s second law*

19. You are told that an air conditioner has cooled a room by 500 Btu over a
certain period of time. What is this amount of energy in kWh?
A. 147 kWh
B. 14.7 kWh
C. 1.47 kWh
D. 0.147 kWh*

20. A bleeder resistor

A. is connected across the capacitor in a power supply.*
B. keeps a transistor from drawing too much current.
PERCDC ECT Review ECT COACHING
C. prevents an amplifier from being overdriven.
D. optimizes the efficiency of an amplifier.

21. What is the value of a resistor with colors from left: Orange, Blue, Gold and
Silver?
A. 34 ohms ± 10%
B. 3.6 ohms ± 10%*
C. 3.4 ohms ± 10%
D. 36 ohms ± 10%

22. The pattern appearing on an oscilloscope when harmonically related signals

are applied to the horizontal and vertical inputs.
A. Lissajous’ pattern *
B. Shockley’s pattern
C. Braun’s pattern
D. Lee de Forest’s pattern

23. A backward-working electric motor, in which mechanical rotation is converted

to electricity, is best described as.
A. an inefficient, energy-wasting device.
B. a motor with the voltage connected the wrong way.
C. an electric generator.*
D. a magnetic field

24. Which of the following constitutes illegal use of ham radio?

A. Selling cars by broadcasting prices to other hams. *
B. Talking about the weather and exchanging local forecasts.
C. Talking about who might be the next president of the United States.
D. Connecting a radio to the Internet.

25. The factor that determines the intensity of electric shock is

A. Current *
B. Voltage
C. Resistance
D. Conductance

26. An act creating the Department of Information and Communications Technology

A. RA 10571
B. RA 10912
C. RA 10854
D. RA 10844 *
PERCDC ECT Review ECT COACHING
27. A number often encountered when taking the ratios of distances in simple
geometric figures such as the pentagon, pentagram, decagon and dodecahedron. It
is denoted as φ and is approximately equal to 1.618.
A. Palindrome
B. Golden ratio*
C. Perfect number
D. Prime number

28. Batteries should be located where temperature range between _____ degrees
Celsius.
A. 12.5 and 25.2
B. 15.5 and 32.2*
C. 15.2 and 52.2
D. 55.5 and 60.3

29. A physical condition that causes a device, a component or an element to fail

to perform in a required manner.
A. damaged
B. hazard
C. fault *
D. short

30. A current that flows from one conductor to ground or to another conductor
owing to any abnormal connection (including an arc) between the two.
A. fault current *
B. dark current
C. Leakage current
D. Dead short

31. Which term describes the rate at which electrical energy is used?
A. Resistance
B. Current
C. Power *
D. Voltage

32. The logarithm of the reciprocal of a number is called _____.

A. Inverse Logarithm
B. Index
C. Cologarithm*
D. Briggsian Logarithm

33. What is a simple resonant or tuned circuit?

A. An inductor and a capacitor connected in series or parallel to form a filter *
PERCDC ECT Review ECT COACHING
B. A type of voltage regulator
C. A resistor circuit used for reducing standing wave ratio
D. A circuit designed to provide high fidelity audio

34. What does ASEANMRA mean?

A. ASEAN Mutual Referral Arrangement
B. ASEAN Mutual Referral Agreement
C. ASEAN Mutual Recognition Arrangement*
D. ASEAN Mutual Recognition Agreement

35. What is the typical bandwidth of analog fast-scan TV transmissions on the 70

cm band?
A. More than 10 MHz
B. About 6 MHz *
C. About 3 MHz
D. About 1 MHz

36. Why is it unwise to install a 20-ampere fuse in the place of a 5-ampere fuse?
A. The larger fuse would be likely to blow because it is rated for higher current
B. The power supply ripple would greatly increase
C. Excessive current could cause a fire *
D. All of these choices are correct

37. What is inside the envelope of a triode tube?

A. argon
B. a vacuum*
C. air
D. neon

38. If you do not wish to have current flowing in the grid circuit of a vacuum
tube, the grid should be:
A. positive with respect to the anode
B. negative with respect to the cathode*
C. positive with respect to both cathode and anode
D. positive with respect to the cathode

39. How do you find a resistor's tolerance rating?

A. By using Thevenin's theorem for resistors
B. By reading the resistor's color code*
C. By reading its Baudot code
D. By using a voltmeter
PERCDC ECT Review ECT COACHING
40. In a circuit where the components are tuned to resonate at a higher frequency
than applied, the circuit is most likely a:
A. a frequency multiplier*
B. a VHF/UHF amplifier
C. a linear amplifier
D. a frequency divider

41. What stage in a transmitter would change a 5.3-MHz input signal to 14.3 MHz?
A. A linear translator
B. A frequency multiplier
C. A mixer*
D. A beat frequency oscillator

42. What is a flip-flop circuit?

A. A binary sequential logic element with eight stable states
B. A binary sequential logic element with two stable states*
C. A binary sequential logic element with four stable states
D. A binary sequential logic element with one stable state

43. What type of digital logic is also known as a latch?

A. A decade counter
B. An Or gate
C. A flip-flop*
D. An op-amp

44. In a multivibrator circuit, when one transistor conducts, the other is:
A. amplified
B. reverse-biased
C. cut off*
D. forward-biased

45. What factor determines the bandwidth and response shape of a crystal lattice
filter?
A. The relative frequencies of the individual crystals*
B. The centre frequency chosen for the filter
C. The gain of the RF stage following the filter
D. The amplitude of the signals passing through the filter

46. For single-sideband phone emissions, what would be the bandwidth of a good
crystal lattice filter?
A. 15 kHz
B. 500 Hz
C. 2.1 kHz*
PERCDC ECT Review ECT COACHING
D. 6 kHz

47. The main advantage of a crystal oscillator over a tuned LC oscillator is:
A. longer life under severe operating use
B. freedom from harmonic emissions
C. simplicity
D. much greater frequency stability*

48. Piezoelectricity is generated by:

A. touching crystals with magnets
B. adding impurities to a crystal
C. deforming certain crystals*
D. moving a magnet near a crystal

49. Crystals are sometimes used in a circuit which has an output an integral
multiple of the crystal frequency. This circuit is called:
A. a crystal multiplier
B. a crystal lattice
C. a crystal ladder
D. an overtone oscillator*

50. What are the distinguishing features of a Butterworth filter?

A. The product of its series and shunt element impedances is a constant for all
frequencies
B. It only requires conductors
C. It has a maximally flat response over its pass-band*
D. It only requires capacitors

51. Which filter type is decribed as having ripple in the passband and a sharp
cutoff?
A. An active LC filter
B. A passive op-amp filter
C. A Chebyshev filter*
D. A Butterworth filter

52. What is the easiest amplitude dimension to measure by viewing a pure sine
wave on an oscilloscope?
A. Peak-to-peak voltage*
B. Peak voltage
C. RMS voltage
D. Average voltage
PERCDC ECT Review ECT COACHING
53. What is the equivalent to the RMS value of an AC voltage?
A. The AC voltage found by taking the square of the average value of the
peak AC voltage
B. The AC voltage causing the same heating of a given resistor as a DC voltage
of the same value*
C. The DC voltage causing the same heating of a given resistor as the
peak AC voltage
D. The AC voltage found by taking the square root of the average AC value

54. What is the best instrument to use to check the signal quality of a CW
or single-sideband phone transmitter?
A. A sidetone monitor
B. An oscilloscope*
C. A signal tracer and an audio amplifier
D. A field-strength meter

55. A meter has a full-scale deflection of 40 microamps and an internal

resistance of 96 ohms. You want it to read 0 to 1 mA. The value of the shunt to
be used is:
A. 24 ohms
B. 16 ohms
C. 4 ohms*
D. 40 ohms

56. A moving-coil milliammeter having a full-scale deflection of 1 mA and an

internal resistance of 0.5 ohms is to be converted to a voltmeter of 20 volts
fullscale deflection. It would be necessary to insert a:
A. series resistance of 1 999.5 ohms
B. series resistance of 19 999.5 ohms*
C. shunt resistance of 19 999.5 ohms
D. shunt resistance of 19.5 ohms

57. A voltmeter having a range of 150 volts and an internal resistance of 150 000
ohms is to be extended to read 750 volts. The required multiplier resistor would
have a value of:
A. 1 500 ohms
B. 750 000 ohms
C. 1 200 000 ohms
D. 600 000 ohms*

58. The sensitivity of an ammeter is an expression of:

A. the amount of current causing full-scale deflection*
B. the resistance of the meter
PERCDC ECT Review ECT COACHING
C. the loading effect the meter will have on a circuit
D. the value of the shunt resistor

59. Voltmeter sensitivity is usually expressed in ohms per volt. This means that
a voltmeter with a sensitivity of 20 kilohms per volt would be a:
A. 50 microampere meter*
B. 1 milliampere meter
C. 50 milliampere meter
D. 100 milliampere meter

60. The sensitivity of a voltmeter, whose resistance is 150 000 ohms on the 150-
volt range, is:
A. 100 000 ohms per volt
B. 1000 ohms per volt*
C. 10 000 ohms per volt
D. 150 ohms per volt

61. What happens inside a multimeter when you switch it from a lower to a higher
voltage range?
A. Resistance is reduced in series with the meter
B. Resistance is added in series with the meter*
C. Resistance is reduced in parallel with the meter
D. Resistance is added in parallel with the meter

62. At what line impedance do most RF wattmeters usually operate?

A. 25 ohms
B. 100 ohms
C. 300 ohms
D. 50 ohms*

63. For the same transformer secondary voltage, which rectifier has the highest
average output voltage?
A. Half-wave
B. Quarter-wave
C. Bridge*
D. Full-wave

64. A full-wave bridge rectifier circuit makes use of both halves of

the AC cycle, but unlike the full-wave centre-tap rectifier circuit it does not
require:
A. any output filtering
B. a centre-tapped primary on the transformer
C. a centre-tapped secondary on the transformer*
PERCDC ECT Review ECT COACHING
D. diodes across each leg of the transformer

65. The output from a full-wave bridge rectifier circuit will appear to be:
A. double that of the full-wave centre-tap rectifier
B. half that of the full-wave centre-tap rectifier
C. the same as the full-wave centre-tap rectifier*
D. the same as the half-wave rectifier

66. The ripple frequency produced by a full-wave power supply connected to a

normal household circuit is:
A. l20 Hz*
B. 60 Hz
C. 90 Hz
D. 30 Hz

67. The ripple frequency produced by a half-wave power supply connected to a

normal household circuit is:
A. 90 Hz
B. 60 Hz*
C. l20 Hz
D. 30 Hz

68. Filter chokes are rated according to:

A. reactance at 1000 Hz
B. power loss
C. breakdown voltage
D. inductance and current-handling capacity*

69. The advantage of the capacitor input filter over the choke input filter is:
A. better filtering action or smaller ripple voltage
B. improved voltage regulation
C. lower peak rectifier currents
D. a higher terminal voltage output*

70. There are two types of filters in general use in a power supply. They are
called:
A. choke output and capacitor output
B. choke input and capacitor input*
C. choke input and capacitor output
D. choke output and capacitor input

71. What is one characteristic of a switching voltage regulator?

PERCDC ECT Review ECT COACHING
A. The control device is switched on and off, with the duty cycle proportional
to the line or load conditions*
B. The conduction of a control element is varied in direct proportion to the
line voltage or load current
C. It provides more than one output voltage
D. It gives a ramp voltage at its output

72. What device is typically used as a stable reference voltage in a linear

voltage regulator?
A. An SCR
B. A varactor diode
C. A junction diode
D. A zener diode*

73. What type of linear regulator is used in applications requiring efficient

utilization of the primary power source?
A. A shunt regulator
B. A constant current source
C. A shunt current source
D. A series regulator*

74. What type of linear voltage regulator is used in applications requiring a

constant load on the unregulated voltage source?
A. A constant current source
B. A shunt current source
C. A shunt regulator*
D. A series regulator

75. How is remote sensing accomplished in a linear voltage regulator?

A. An error amplifier compares the input voltage to the reference voltage
B. A load connection is made outside the feedback loop
C. A feedback connection to an error amplifier is made directly to the load*
D. By wireless inductive loops

76. When extremely low ripple is required, or when the voltage supplied to the
load must remain constant under conditions of large fluctuations of current and
line voltage, a closed-loop amplifier is used to regulate the power supply. There
are two main categories of electronic regulators. They are:
A. linear and switching*
B. non-linear and switching
C. linear and non-linear
D. "stiff" and switching
PERCDC ECT Review ECT COACHING
77. What is a three-terminal regulator?
A. A regulator that supplies three voltages at a constant current
B. A regulator containing a voltage reference, error amplifier, sensing
resistors and transistors, and a pass element*
C. A regulator containing three error amplifiers and sensing transistors
D. A regulator that supplies three voltages with variable current

78. A modern type of regulator, which features a reference, high-

gain amplifier, temperature-compensated voltage sensing resistors and transistors
as well as a pass-element is commonly referred to as a:
A. nine-pin terminal regulator
B. three-terminal regulator*
C. twenty-four pin terminal regulator
D. six-terminal regulator

79. In any regulated power supply, the output is cleanest and the regulation is
best:
A. at the point where the sampling network or error amplifier is connected*
B. across the secondary of the pass transistor
C. across the load
D. at the output of the pass transistor

80. Vesting the jurisdiction, control and regulation over the Philippine
Communication Satellite Corporation with the National Telecommunications
Commission.
A. EO 312
B. EO 196*
C. EO 269
D. EO 430

81. Prescribing the policy guidelines for the compulsory interconnection of

authorized public telecommunications carriers in order to create a universally
accessible and fully integrated nationwide telecommunications network and thereby
encourage greater private sector investment in telecommunications.
A. EO 50
B. EO 59*
C. EO 209
D. EO 109

82. Any one of a number of measures permitting direct dealings between authorized
entities and international satellite system providers at specified levels as
defined by the NTC.
A. Direct Home TV
PERCDC ECT Review ECT COACHING
B. Direct Access *
C. Fixed Satellite Service
D. Indirect Access

83. Mobile phone service center shall properly identify its business and location
by posting conspicuously at the entrance of its premises a signboard of at least
_____ dimension which shall indicate clearly its business name, the type of
services it offers, its full business address and the MPSC permit.
A. 50cm by 50cm
B. 50cm by 150cm
C. 50cm by 100cm*
D. 75cm by 75cm

84. The RF power output of a transmitter in a cellular mobile telephone system

authorized by NTC for use in the Philippines.
A. 20.5 dBm
B. 22.1 dBm
C. 31.5 dBm
D. 34.8 dBm *

85. Refers to a grant consistent with the telecommunications policies and

objectives to a qualified applicant, after due notice and hearing, of a final
authority to own, operate and maintain a public telecommunications
facility/service by the National Telecommunications Commission.
A. Certificate of Authority
B. Certificate of Public Convenience and Necessity *
C. Franchise
D. Provisional Authority

86. Refers to the enhanced services beyond those ordinarily provided by local
exchange and inter-exchange operators, and overseas carriers through circuit
switched networks.
A. VOIP
B. VAS *
C. CPE
D. PTE

87. A permit issued to CATV operators to operate in a particular area.

A. Certificate of Authority *
B. Franchise
C. Permit to Operate
D. Certificate of Public Convenience and Necessity
PERCDC ECT Review ECT COACHING
88. An act providing for the regulation of radio stations and radio
communications in the Philippine islands, and for other purposes.
A. RA 3846 *
B. RA 6875
C. RA 7925
D. RA 5743

89. The hum and noise of the receiver should not be greater than _____ in the
cellular mobile telephone system authorized by NTC for use in the Philippines.
A. 30dB
B. 40dB
C. 45dB *
D. 55dB

90. An act known as the "Municipal Telephone Act."

A. RA 8975
B. RA 5734
C. RA 6849 *
D. RA 3846

91. Regulating the operation of cable antenna television (CATV) systems in the
Philippines, and for other purposes.
A. EO 205 *
B. EO 109
C. EO 132
D. EO 266

92. The minimum echo return loss in a Key Telephone System (KTS) authorized by
the NTC for use in the Philippines.
A. 3dB
B. 5dB
C. 7dB *
D. 9dB

93. An undertaking the object of which is to transmit audio, video, text, images
or other signals or messages for reception of a broad audience in a geographical
area via wired or wireless means.
A. Broadcasting *
B. Unauthorized service
C. Telegraphy
D. Telecommunications
PERCDC ECT Review ECT COACHING
94. The latest issued telecommunications law which addresses the public
telecommunication regulation.
A. E. O. 436
B. E. O. 546
C. R. A. 7925 *
D. R. A. 3846

95. The average resistance of a dry adult human body is approximately:

A. 10 000 ohms
B. 100 000 ohms
C. 1 000 000 ohms *
D. 100 ohms

96. Ventricular fibrillation is likely to occur when a 60 Hz rms current of _____

amperes and above passes through one’s chest cavity.
A. 0.010
B. 0.11
C. 0.030 *
D. 0.33

97. What would be the MPD for a 50-year old man?

A. 80 REMs
B. 40 REMs
C. 160 REMs *
D. 240 REMs

98. Based on Memorandum Circular MC No. 4-09-88 (Prescribed Equipment for Ship
Stations of Various Vessels Plying Domestic Routes and Other Requirements)what is
the Prescribed Radio Installation for Cargo Vessels below 350 GT and less than 5
hours of navigation
A. VHF with capability on 156.2/156.8/156.4 MHz
B. VHF with capability on 156.8/156.3/156.6 MHz
C. VHF with capability on 156.6/156.5/156.3 MHz
D. Radio installation optional *

99. Based on Memorandum Circular MC No. 4-09-88 (Prescribed Equipment for Ship
Stations of Various Vessels Plying Domestic Routes and Other Requirements)what is
the Prescribed Radio Installation for Passenger Vessels 350 GT and above and more
than 5 hours of navigation
A. Telegraphy installation with capability on 500KHz
B. SSB with capability on 2182/4125/6215.5 KHz
C. VHF with capability on 156.8/156.3/156.6 MHz
D. All of the Above *
PERCDC ECT Review ECT COACHING

100. A permit issued by the National Telecommunications Commission authorizing

the holder thereof to engage in the purchase, sale, lease, and/or retail of
mobile phones including parts and accessories thereof
A. Mobile Phone Seller Permit
B. Mobile Phone Dealer Permit *
C. Mobile Phone Buyer Permit
D. All of these