Description : What device measures the angle between two radio frequencies and also the direction of propagation of a wave? A. Densimeter B. Absorption wavemeter C. Goniometer D. Ergometer
Last Answer : C. Goniometer
Description : Which tester is used to measure SWR? A. Spectrum analyzer B. Multimeter C. Reflectometer D. Oscilloscope
Last Answer : C. Reflectometer
Description : Used to test a fiber optics splice ∙ a. Spectrum analyzer ∙ b. Oscilloscope ∙ c. Optical power meter ∙ d. Field strength meter
Last Answer : c. Optical power meter
Description : What term is used to describe a spread spectrum communications system in which a very fast binary bit stream is used to shift the phase of an RF carrier? A. Frequency hopping B. Direct sequence C. Binary phase-shift keying D. Phase compandored spread spectrum
Last Answer : B. Direct sequence
Description : When measuring a transmitter’s frequency against a suitable standard, the frequency to be measured is taken from the A. oscillator stage B. intermediate amplifier C. buffer stage D. final RF stage
Last Answer : D. final RF stage
Description : List two types of oscillator, which generates frequency in RF range.
Last Answer : Types of Oscillators generating frequencies in RF range: i) Hartley Oscillator ii) Colpitt’s Oscillator iii) Clapp Oscillator
Description : You are measuring noise at a -6 dB level point, using the Lenkurt 601A, F1A weighting network, and a flat meter. The meter reading is -59 dBm. This is _________ dBa0. A. 24 B. 12 C. 23 D. 32
Last Answer : D. 32
Description : You are measuring noise at a +3 dB level point, using the Lenkurt 601A, F1A weighting network, and a flat meter. The meter reading is -57dBm. This is ________dBa0. A. 20 B. 15 C. 25 D. 17
Last Answer : C. 25
Description : You are measuring noise in a voice channel with a Lenkurt 601A, F1A weighting network and a flat meter. Your meter reads -47dBm. What is this reading in dBa? A. 77 dBa B. 35 dBa C. 38 dBa D. 32 dBa
Last Answer : C. 38 dBa
Description : You are measuring noise in a voice channel at 7 dB test point level. The meter reads -56 dBm (FIA weighted). What is the reading in dBrnc? A. 20 B. 32 C. 35 D. 25
Last Answer : C. 35
Description : You are measuring a voice channel at a -4 dB test point level, the meter reads -73 dBm (pure test tone) convert the reading in dBmCO. A. 16 B. 18 C. 22 D. 12
Last Answer : C. 22
Description : In measuring noise in a voice channel at a 4 dB test point level, the meter reads -70 dBm (F1A weighted), convert the reading to pWp. A. 53 B. 93 C. 63 D. 83
Last Answer : B. 93
Description : ___________ is device that measures the internal open circuit voltage of an equivalent noise generator having an impedance of 600Ω and delivering noise power to a 600 Ω load. A. Psophometer B. Barometer C. Reflectometer D. Voltmeter
Last Answer : A. Psophometer
Description : The product of the radiated RF power of a transmitter and the gain of the antenna system in a given direction relative to an isotropic radiator is called ____. A. Effective Radiated Power (ERP) B. Effective Isotropic Radiated Power (EIRP) C. Radiated Power D. Transmit Power
Last Answer : B. Effective Isotropic Radiated Power (EIRP)
Description : What is the meaning of forward power? A. The power traveling from the transmitter to the antenna. B. The power radiated from the top of an antenna system. C. The power produced during the positive half of an RF cycle. D. The power used to drive a linear amplifier.
Last Answer : A. The power traveling from the transmitter to the antenna.
Description : One of the following is a high powered RF ac basic transmitter that has two or more stages, the oscillator stage which determines the frequency opereation and RF amplifier stage orstages that develop the ... to develop a good frequency stability. A. Goldsmith B. MOPA C. Alexanderson D. Hartley
Last Answer : B. MOPA
Description : Which of the following is one of the possible causes for a slow drift of frequency in a self exited transmitter oscillator circuits resulting to a poor frequency stability? A. Poor soldered connections ... , or antenna circuits D. DC and RF heating of resistors, causing then to change values.
Last Answer : D. DC and RF heating of resistors, causing then to change values.
Description : ECE Board Exam November 1996 What is the applied power if a thermal RF wattmeter is connected to a transmitter through a variable attenuator? The wattmeter reads 84 mW when 15 dB of attenuation is used. A. 4.656 watts B. 2.656 watts C. 3.656 watts D. 2.856 watts
Last Answer : B. 2.656 watts
Last Answer : A. PAM
Description : What instrument normally measures the virtual height of ionosphere? A. Ionosonde B. Altimeter C. Field meter D. Radar
Last Answer : A. Ionosonde
Description : An instrument for recording waveforms of audio frequency. A. Oscilloscope B. Phonoscope C. Radioscope D. Audioscope
Last Answer : B. Phonoscope
Description : Dryness fraction of wet steam is defined as the ratio of mass of vapour in the mixture to the mass of mixture __________ calorimeter is not used for measuring the dryness fraction of steam. (A) Bomb (B) Separating (C) Bucket (D) Throttling
Last Answer : A) Bomb
Description : __________ calorimeter is normally used for measuring the dryness fraction of steam, when it is very low. (A) Bucket (B) Throttling (C) Separating (D) A combination of separating & throttling
Last Answer : (D) A combination of separating & throttling
Description : How is bandwidth increased in Cdma2000? a) Clubbing adjacent radio channels b) Changing the hardware of base stations c) Change of spectrum d) Change of RF equipment
Last Answer : a) Clubbing adjacent radio channels
Description : The region of the electromagnetic spectrum immediately above the frequencies to which the human eye is sensitive is called: w) ir x) ultra-violet y) rf z) gamma ray
Last Answer : ANSWER: X -- ULTRA-VIOLET
Description : A shunt-fed quarter-wavelength Marconi antenna A. has maximum RF impedance to ground at its feedpoint B. has a current null at its feedpoint C. has a zero DC resistance to ground D. has zero RF resistance to ground
Last Answer : C. has a zero DC resistance to ground
Description : A method of multiple accessing where a given RF channel bandwidth is divided inot smaller frequency band. A. CDMA B. ANIK-D C. TDMA D. FDMA
Last Answer : D. FDMA
Description : Calculate the noise figure of the receiver whose RF amplifier has an input resistance of 1000Ω and an equivalent shot-noise resistance of 2000Ω, a gain of 25 and load resistance of 125 kΩ. Given that the bandwidth is 1. ... to an antenna with an impedance of 75Ω. A. 30.3 B. 3.03 C. 303 D. .303
Last Answer : A. 30.3
Description : What organization has published safety guidelines for the maximum limits of RF energy near the human body? A. The American National Standards Institute (ANSI). B. The Environmental Protection ... Communications Commission (FCC). D. The Institute Of Electrical and Electronics Engineers (IEEE).
Last Answer : A. The American National Standards Institute (ANSI).
Description : What establishes the receiver bandwidth? A. RF amplifier B. Mixer C. Local oscillator D. IF amplifier
Last Answer : D. IF amplifier
Description : Why is the physical length of a coaxial cable transmission line shorter than its electrical length? A. Skin effect is less pronounced in the coaxial cable B. RF energy moves slower along the ... higher in the parallel feed line D. The characteristic impedance is higher in the parallel feed line
Last Answer : B. RF energy moves slower along the coaxial cable
Description : What consists the front-end circuit of a VHF TV superheterodyne receiver? A. Mixer, RF amplifier and AFC? B. RF amplifier, Band pass filter and mixer C. Local oscillator, mixer and RF amplifier D. Local oscillator, AGC and antenna
Last Answer : C. Local oscillator, mixer and RF amplifier
Description : Type of emission produced by one of the early radio transmitter in trains of damped RF ac waves where its oscillator is coupled to a long wire antenna, normally used in radio telegraph and having sidebands on its carrier. A. Digital emission B. Key emission C. Cycle emission D. Spark emission
Last Answer : D. Spark emission
Description : Which of the following parts of the radio receiver represent the component that extracts the desire RF signal from the electromagnetic wave? A. AF amplifier B. Antenna C. Detector D. Crystal
Last Answer : B. Antenna
Description : One of the following is a possible cause of an abrupt frequency variation in a self exited transmitter oscillator circuits resulting to a poor frequency stability to hold a constant frequency ... capacitor in the oscillator D. Loose connections in the oscillator, amplifier, or antenna circuits.
Last Answer : D. Loose connections in the oscillator, amplifier, or antenna circuits.
Description : Refers to one of the front end circuit of a VHF TV superheterodyne receiver which is usually a separate circuit coupled to the mixer. A. Antenna feed B. AGC C. RF amplifier D. Local oscillator
Last Answer : D. Local oscillator
Description : When adjusting an RF filter on a transmitter using a dummy load, how much watts dissipation should it stand to test a 150 watts transmitter? A. 75 watts B. 300 watts C. 50 watts D. 150 watts
Last Answer : D. 150 watts
Description : How can receiver desensitizing be reduced? A. Increase the receiver bandwidth B. Ensure good RF shielding between the transmitter and receiver C. Increase the transmitter audio gain D. Decrease the receiver squelch, gain.
Last Answer : D. Decrease the receiver squelch, gain.
Description : Which of the following is not a baseband signal modulation? A. RF carrier B. Video System C. Audio signal D. Binary coded pulses
Last Answer : A. RF carrier
Description : After the IF stages have been aligned, the next stage to align in FM receiver is. A. local oscillator B. limiter stage C. RF amplifier D. mixer stage
Last Answer : A. local oscillator
Description : Cross modulation on a receiver is eliminated at the A. RF stage B. mixer stage C. IF stage D. detector stage
Last Answer : D. detector stage
Description : ECE Board Exam March 1996 What is the purpose of the receiver's squelch circuit? A. To overcome fluctuations in the level the RF signal arriving at the receiver antenna B. To prevent ... signals D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal
Last Answer : D. To prevent amplified noise from reaching the loudspeaker during the absence of an incoming signal
Description : Soil salinity is measured by: (a) Potometer (b) Porometer (c) Conductivity meter (d) Calorimeter
Last Answer : Ans. ((c))
Description : Which apparatus is used to measure the intensity of light? (1) Lux meter (2) Calorimeter (3) Anemometer (4) Altimeter
Last Answer : Lux meter
Description : What generates a light beam of a specific visible frequency? a. Laser b. Maser c. Infrared d. Flashlight
Last Answer : a. Laser
Description : ________ generates light beam at a specific visible frequency. A. Glass fiber B. Infrared C. Light waves D. Laser
Last Answer : D. Laser
Description : ECE Board Exam March 1996 What is the purpose of a beat frequency oscillator (BFO)? A. Aid in the reception of weak voice-modulated signals B. Generates a signal, whose frequency is the ... reception D. Generates an output, whose frequency differs from that of the intermediate frequency by 1 kHz
Last Answer : C. Generates a 1kHz note for Morse code reception
Description : The most common water flow measuring device which measures water flow in open conduit is
Last Answer : Ans.Parshall/Venturi flume
Description : A tunable RF instrument, which, by means of a sharp dip of an indicating meter, indicates resonance with an external circuit under test
Last Answer : dip meter
Description : In measuring crosstalk using dBx unit the reference power is A. 1 mW B. 1 W C. 1 pW D. 6 mW
Last Answer : C. 1 pW