ECT-Refresher 1

In a frequency modulation receiver, the output of the high frequency oscillator is fed to the: a. RF amplifier b. limiter c. antenna d. mixer

d

Temperature sensing can be achieved by the use of a. thermocouples b. RTDs c. thermistors d. All of the above

d

. A trapezoid has area of 36 m2 and an altitude of 2 m. Its two bases have ratio of 4:5. What are the lengths of the bases? a. (16,20) b. (8,10) c. (12,15) d. (14,10)

a

. If the same five 0.050 uF capacitors are connected in series, the total capacitance will be: A. 0.010 μF B. 0.25 μF C. 0.50 μF D. 0.025 μF

a

. In series resonance, which statement is true? a. low input impedance b. high input impedance c. current is minimum d. donor circuit

a

. The instrument used for measuring the flow of electrical current a. Ammeter b. faradmeter c. wattmeter d. voltmeter

a

. Which of the following measurements are commonly made using a multimeter? a. Voltage and resistance b. SWR and RF power c. Signal strength and noise d. Impedance and reactance

a

Any transmission, emission or reception of voice, data, electronic messages, text, written or printed matter, fixed or moving pictures or images, words, music or visible or audible signals or sounds, or any information, intelligence and/or control signals of any design/format and for any purpose, by wire, radio, spectral, visual/optical/light, or other electronic, electromagnetic and technological means. a. telecommunications b. Information and Communications Technology c. Broadcast, Broadcasting d. Industrial Plan

a

At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 μF? a. 7.12 kHz b. 7.12 Hz c. 7.12MHz d. 7.12 GHz

a

Compared to an effective voltage of 120 VAC, the average heat energy out of a resistor is __________ for a voltage of 120 VDC. a. the same b. higher c. lower d. nonexistent

a

Date of approval of Republic Act 9292 a. April 17, 2004 b. May 24, 2004 c. February 2, 2004 d. April 16, 2004

a

Given that "w" varies directly as the product of "x" and "y" and inversely as the square of "z" and that w = 4 when x = 2, y = 6 and z = 3. Find the value of "w" when x = 1, y = 4, and z = 2. a. 3 b. 4 c. 5 d. 6

a

How does a capacitor react to AC? a. As the frequency of the applied AC increases, the reactance decreases b. As the frequency of the applied AC increases, the reactance increases c. As the amplitude of the applied AC increases, the reactance increases d. As the amplitude of the applied AC increases, the reactance decreases

a

How many watts of electrical power are used by a 12-VDC light bulb that draws 0.2 ampere? a. 2.4 watts b. 60 watts c. 24 watts d. 6 watts

a

If you wish to reduce the current flowing in a field effect transistor, you could: a. increase the reverse bias voltage b. decrease the reverse bias voltage c. increase the forward bias voltage d. increase the forward bias gain

a

One result of a slight mismatch between the power amplifier of a transmitter and the antenna would be: a. reduced antenna radiation b. smaller DC current drain c. lower modulation percentage d. radiated key-clicks

a

What factors determine the characteristic impedance of a parallel-conductor antenna feed line? a. The distance between the centres of the conductors and the radius of the conductors b. The distance between the centres of the conductors and the length of the line c. The radius of the conductors and the frequency of the signal d. The frequency of the signal and the length of the line

a

What is the basic law that provides for the regulation of radio station, communications in the Philippines and other purposes? A. R. A. 3846 B. D. O. 11 C. D. O. 88 D. D. O. 5

a

What is the unit of magnetic flux in SI system? a. Weber b. Maxwell c. Tesla d. Gauss

a

Why would there be a switch in a high-voltage power supply to turn off the power if its cabinet is opened? a. To keep anyone opening the cabinet from getting shocked by dangerous high voltages b. To keep dangerous RF radiation from leaking out through an open cabinet c. To keep dangerous RF radiation from coming in through an open cabinet d. To turn the power supply off when it is not being used

a

. A battery with a capacity of 600 ampere-hours should provide 3 amperes for a maximum of how many hours? a. 100 hrs b. 200 hrs c. 300 hrs d. 600 hrs

b

. Battery rated 24 V supplies 10 A. Terminal voltage is measured as 23.5 V. what is the resistance of the external circuit. a. 23.5 ohms b. 2.35 ohms c. 24 ohms d. 235 ohms

b

. Fault finding in a power supply of an amateur transmitter while the supply is operating is not a recommended technique because of the risk of: a. damaging the transmitter b. electric shock c. overmodulation d. blowing the fuse

b

. In a frequency modulation transmitter, the _________ is located between the modulator and the frequency multiplier. a. speech amplifier b. oscillator c. power amplifier d. microphone

b

. In a mains power transformer, the primary winding has 250 turns, and the secondary has 500. If the input voltage is 110 volts, the likely secondary voltage is: a. 440 V b. 220 V c. 560 V d. 24 V

b

. In order for a diode to conduct, it must be: a. close coupled b. forward-biased c. enhanced d. reverse-biased

b

. LVDT is a a. pressure transducer b. displacement transducer c. velocity transducer d.acceleration transducer

b

. Professional Regulations Commission was created under a. PD 323 b. PD 223 c. PD 232 d. RA 223

b

. Section 32 of RA 9292 a. Practice of Profession b. Integrated and Accredited Professional Organization c. Continuing Professional Education and/or Development Programs d. Foreign Reciprocity

b

. Simplify: ((x^2y^3z^-2)^-3(x^-3yz^3)^(-1/2))/(xyz^-3)^(-5/2) A. 1/(x^2y^7z^5) B. 1/ (x^2 y^7 z^3) C. 1/ (x^2 y^5 z^7) D. 1/ (x^5 y^7 z^2)

b

. Solve for x in the equation: arc tan (x + 1) + arc tan (x - 1) = arc tan (12) A. 1.5 B. 1.33 C. 1.20 D. 1.25

b

. Which law provides for a national policy on the operation and used of international satellite communications in the country? a. EO 468 b. EO 109 c. EO 205 d. EO 467

b

. Which of the following represents bearing measurements? a. x=y b. north-south c. east-west d. x=-y

b

A triangle has angles with ratios of 4:3:2. The first and third angles are supplementary. What are the angles? a. 130, 90, 50 b. 120, 90, 60 c. 140, 80, 40 d. 150, 60, 30

b

How many edges do a pentagonal prism has? a. 10 b. 15 c. 12 d. 7

b

If ten resistors of equal value were wired in parallel, the total resistance would be: a. 10 / R b. R / 10 c. 10 x R d. 10 + R

b

PECE, ECE and ECT are the categories covered by RA 9292. What section of RA 9292 is this? a. Section 5 b. Section 4 c. Section 3 d. Section 2

b

Plot f(x) = b^(x), when 0<b<1 a. falls from right to left b. falls from left to right c. asymptotic to y - axis d. curve on y<0

b

RLC in parallel, R = 10 ohms, L = 0.01 Henry, C = 800 uF, 240V at 50 Hz. Find the impedance. a. 3.808 Ω b. 8.308 Ω c. 8.803 Ω d. 8.038 Ω

b

Solve for x: x = ((b^2 - 4b + 16)(b^2 - 16)/(b^3 + 64)) A. b + 4 B. (b - 4) / (b + 2) C. (b^2 - 4 )/ (b+2) D. b - 4

b

The chairperson of the PRC shall include in the Commission's program the implementation of RA9292, the funding of w/c shall be included in the Annual General Appropriation Act. a. Sec. 39 b. Sec. 40 c. Sec. 41 d. Sec 42

b

The perimeter of a triangle is 102 cm. If two sides are 24 cm and 32 cm, what is the area of the triangle? a. 341.22 cm2 b. 361.68 cm2 c. 351.21 cm2 d. 333.12 cm2

b

Title of Republic Act 5734 a. The Electronics and Communication Act of the Philippines b. The Electronics and Communications Act of the Philippines c. The Electronics Act of the Philippines d. The Law of Electronics and Communications Engineering

b

Two resistors in series connected to a 24 v battery. One resistor is 22 ohms with a power of 5 watts. Find the value of the other resistor. a. 2.83 Ω b. 28.3 Ω c. 283.4 Ω d. 0.283 Ω

b

What is otherwise known as "PRC modernization law"? A. R. A. 8891 B. R. A. 8981 C. R. A. 8918 D. R. A. 8198

b

. An important difference between a conventional flashlight battery and a lead acid battery is that only the lead acid battery: a. can be completely discharged b. has two terminals, c. can be repeatedly recharged d. contains an electrolyte

c

. Given input voltage of 2 V, and gain is 20 dB. What is the output voltage. a. 2 V b. 0.2 V c. 20 V d. 200 V

c

. If f(x) = tan x, find the y-intercept a. (pi, 0) b. (-pi/2, 0) c. (0, 0) d. (0, pi/2)

c

. In a Yagi-Uda 3 element directional antenna, the ________ is the longest radiating element. a. director b. driven element c. reflector d. boom

c

. The distance from the transmitter to the nearest point where the sky wave returns to the earth is called the: a. skip zone b. angle of radiation c. skip distance d. maximum usable frequency

c

. Triggered sweep in oscilloscope a. amplitude b. graticule c. timing d. frequency

c

. What happens to a signal's frequency as its wavelength gets longer? a. It stays the same b. It disappears c. It goes down d. It goes up

c

. What is the next step after discovering a faulty gate within an IC? A.repair the gate B. resolder the tracks C.replace the IC involved D. recheck the power source

c

. When efficiency of transformer decreases. What happens? a. power gain increases b. output impedance increases c. more heat is dissipated d. none of the above

c

. Why do modern HF transmitters have a built-in low pass filter in their RF output circuits? a. To reduce fundamental radiation b. To reduce low frequency interference to other amateurs c. To reduce harmonic radiation d. To reduce RF energy below a cut-off point

c

. Why should you wear a safety belt if you are working on an antenna tower? a. To safely bring any tools you might use up and down the tower b. To keep the tower from becoming unbalanced while you are working c. To prevent you from accidentally falling d. To safely hold your tools so they don't fall and injure

c

Administer and enforce the same as well as to promulgate rules and regulations as public safety and interest may require, to encourage a larger and more effective and efficient use of communication, radio and television broadcasting facilities and spectrum. a. D.O. 6 b. D. O. 11 c. E. O. 546 d. E. O. 223

c

An act declaring the bar and board examinations as civil service examinations . a. RA 9292 b. RA 5734 c. RA1080 d. RA 7925

c

How should you position the antenna of a hand-held transceiver while you are transmitting? a. Pointed away from the station you are contacting b. Pointed towards the station you are contacting c. Away from your head and away from others d. Pointed down to bounce the signal off the ground

c

In a frequency modulation transmitter, the _________ is located between the frequency multiplier and the antenna. a. speech amplifier b. modulator c. power amplifier d. oscillator

c

In terms of the division on screen, the voltage of the waveform in CRO is A. Average voltage B. RMS voltage C. Peak to peak voltage D. Maximum voltage

c

Simplify tanθcotθ - cos2θ a. cos2θ b. tan2θ c. sin2θ d. sec2θ

c

Solve for the value of x: log 2x^3 + log (6/x) = 6.278 A. 379.65 B. 365.97 C. 397.56 D. 356.79

c

The part of a power supply immediately preceding the regulator is: A. The transformer. B. The rectifier. C. The filter. D. The ac input.

c

When a signal is returned to earth by the ionosphere, what is this called? a. Tropospheric propagation b. Ground-wave propagation c. Sky-wave propagation d. Earth-moon-earth propagation

c

Which of the following does not constitute the foundation of ethics? A. Honesty B. Justice C. Integrity D. Courtesy

c

Which of the following types of emission has the narrowest bandwidth? A. FM voice B. SSB voice C. CW D. Slow-scan TV

c

. A permanent magnet would most likely be made from: a. copper b. aluminum c. brass d. steel

d

. Amount as fine for the punishment in the penal provision of doing an acts that's against R.A. 9292 a. Php 100, 000.00 b. Php 1, 000. 00 to 100, 000.00 c. Php 1,000, 000.00 d. Php 100,000.00 to 1,000,000.00

d

. Five 2V cells, each having an internal resistance of 0.2 ohms are connected in series to a load of resistance 14 ohms. The current flowing in the circuit is: a. 10A b. 1.4A c. 1.5A d. 2/3 A

d

. I = 100 mA, R = 500 ohms, t = 2 minutes. Find energy a. 300 J b. 400 J c. 500 J d. 600 J

d

. So-called "transformerless" power supplies are used in some applications (notably tubetype radios and TV receivers). When working on such equipment, one should be very careful because: a. DC circuits are negative relative to the chassis b. chassis connections are grounded by the centre pin of the power source's plug c. the load across the power supply is variable d. one side of the line cord is connected to the chassis

d

. Voltage regulation is the principal application of the: a. junction diode b. light-emitting diode c. vacuum diode d. Zener diode

d

. Which law provides for a national policy on the operation and used of international satellite communications in the country? a. EO 468 b. EO 109 c. EO 205 d. EO 467

d

. Which light bulb consumes energy the fastest? a. 60 W b. 100 W c. 120 W d. 150 W

d

. Which of the following meters would you use to measure the power supply current drawn by a small hand-held transistorized receiver? a. an electrostatic voltmeter b. an RF ammeter c. an RF power meter d. a DC ammeter

d

. Which of the following might damage a multimeter? a. Not allowing it to warm up properly b. Measuring a voltage too small for the chosen scale c. Leaving the meter in the milliamps position overnight d. Attempting to measure voltage when using the resistance setting

d

1. Name three good electrical conductors. A. Copper, gold, mica B. Gold, silver, wood C. Copper, aluminum, paper D..Gold, silver, aluminum

d

Find the 30th term of the arithmetic progression 4, 7, 10, .... A. 75 B. 88 C. 90 D. 91

d

How can you decrease your transmitter's power by 3 dB? a. Divide the original power by 1.5 b. Divide the original power by 3 c. Divide the original power by 4 d. Divide the original power by 2

d

The three main parameters against which the quality of a receiver is measured are: a. selectivity, stability and frequency range b. sensitivity, stability and cross-modulation c. sensitivity, selectivity and image rejection d. sensitivity, selectivity and stability

d

The total capacitance of two or more capacitors in series is: a. always greater than the largest capacitor b. found by adding each of the capacitors together and dividing by the total number of capacitors c. found by adding each of the capacitors together d. Always less than the smallest capacitor

d

The volume of a cube is reduced by how much if all sides are halved? a. 1/8 b. 5/8 c. 6/8 d. 7/8

d

To replace a faulty 10 millihenry choke, you could use two: a. Two 5 millihenry chokes in parallel b. Two 20 millihenry chokes in series c. Two 30 millihenry chokes in parallel d. Two 5 millihenry chokes in series

d

What is the formula for converting frequency to wavelength in meters? a.Wavelength in meters equals frequency in hertz multiplied by 300 b.Wavelength in meters equals frequency in hertz divided by 300 c.Wavelength in meters equals frequency in megahertz divided by 300 d.Wavelength in meters equals 300 divided by frequency in megahertz

d

Which of the below mentioned statements is false regarding a p-n junction diode? a) Diode are uncontrolled devices b) Diodes are rectifying devices c) Diodes are unidirectional devices d) Diodes have three terminals

d

Which test equipment best allows a comparison between input and output signals? a. an oscilloscope b. a logic probe c. a spectrum analyzer d. a multitrace oscilloscope

d

Which type of modulation is most commonly used for VHF and UHF voice repeaters? a. AM b. SSB c. PSK d. FM

d