Description : A horizontal antenna is _____. A. vertically polarized B. horizontally polarized C. centrally polarized D. circularly polarized
Last Answer : B. horizontally polarized
Description : When antennas are closed to the ground, _______ polarization is ideal A. horizontally polarized B. vertically polarized C. circularly polarized D. both A and B
Last Answer : B. vertically polarized
Description : An electromagnetic wave is ________ polarized when the electric field lies wholly in one plane containing the direction of propagation. A. Horizontally B. Linearly C. Circularly D. Vertically
Last Answer : B. Linearly
Description : A horizontal antenna is A. centrally polarized B. vertically polarized C. horizontally polarized D. perpendicularly polarized
Last Answer : C. horizontally polarized
Description : What is a device that detects both vertically and horizontally polarized signals simultaneously? A. Orthomode transducer B. Crystal detector C. Optoisolator D. Isomode detector
Last Answer : A. Orthomode transducer
Description : ______ is a device that detects both vertically and horizontally polarized signals simultaneously. A. Crystal B. Orthomode transducer C. Light transducer D. Optoisolator
Last Answer : B. Orthomode transducer
Description : An ungrounded antenna near the ground A. acts as a single antenna of twice the height B. is unlikely to need an earth mat C. acts as antenna array D. must be horizontally polarized
Last Answer : C. acts as antenna array
Description : A device that radiates electromagnetic energy and or intercepts electromagnetic radation. A. Antenna B. Transmitter C. Transmission line D. Transceiver
Last Answer : A. Antenna
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth. B. The magnetic field is parallel to the earth. C. Both the electric and magnetic fields are horizontal D. Both the electric and magnetic fields are vertical
Last Answer : A. The electric field is parallel to the earth.
Description : What is meant by referring to electromagnetic waves as horizontally polarized? A. The electric field is parallel to the earth B. Both the electric and magnetic fields are vertical C. Both the electric and magnetic fields are horizontal D. The magnetic fields is parallel to the earth
Last Answer : A. The electric field is parallel to the earth
Description : ECE Board Exam March 1996 An antenna that is circularly polarized is the ____________. A. parabolic reflector B. helical C. Yagi-uda D. small circular loop
Last Answer : B. helical
Description : The reddish hue of the Sun at sunset is due to the fact that (a) Sunlight is polarized horizontally when scattered by molecules of the atmosphere (b) Light of short wavelength is ... than light of long wavelength (d) Sunlight is polarized vertically when scattered by molecules of the atmosphere
Last Answer : Ans:(b)
Description : In what range of frequencies are most omnidirectional horizontally polarized antennas used? A. VHF, UHF B. VLF, LF C. SH, EHF D. MF, HF
Last Answer : A. VHF, UHF
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 : Known as the satellite transmitted signal form a satellite transponder to earth’s station. A. Uplink B. Down link C. RHCP D. Vertically polarized
Last Answer : B. Down link
Description : Satellite signal transmitted from a satellite transponder to earth’s station. A. Vertically polarized B. Uplink C. Downlink D. RHCP
Last Answer : C. Downlink
Description : Anungrounded antennanearthe ground a. acts as a single antenna of twice the height b. is unlikely to need a ground screen c. acts as anantennaarray d. must be horizontally polarized
Last Answer : c. acts as anantennaarray
Description : What antenna radiates equally in all directions? A. Vertical antenna B. isotropic antenna C. Horizontal antenna D. Dipole antenna
Last Answer : B. isotropic antenna
Description : A simple half-wavelength antenna radiates the strongest signal A. at 45 degrees to its axis B. parallel to its axis C. at right angles to its axis D. at 60 degrees to its axis
Last Answer : C. at right angles to its axis
Description : What is the front-to-back ratio of an antenna which radiates 500 watts in a northernly direction and 50 watts in a southernly direction? A. 25000 dB B. 10 dB C. 100 dB D. 20 dB
Last Answer : B. 10 dB
Description : Which antenna radiates an omnidirectional pattern in the horizontal plane with vertical polarization? A. Marconi antenna B. Discone antenna C. Horn antenna D. Helical antenna
Last Answer : A. Marconi antenna
Description : Any energy which radiates in the form of radio waves, infrared waves, light waves, x-rays, etc. A. Radiant energy B. Electromagnetic C. Heat D. Ultraviolet
Last Answer : B. Electromagnetic
Description : What is the gain of four identically polarized antennas stacked one above the other and fed in phase? A. 3 dB over the gain of one antenna B. 10 dB over the gain of one antenna C. 4 dB over the gain of one antenna D. 6 dB over the gain of one antenna
Last Answer : D. 6 dB over the gain of one antenna
Description : An antenna efficiency is computed by using one of the following equations. A. Efficiency = (radiation resistance / transmission resistance) B. Efficiency = (total resistance / radiation resistance) x ... / transmitter output) x 100% D. Efficiency = (radiation resistance / total resistance) x 100%
Last Answer : D. Efficiency = (radiation resistance / total resistance) x 100%
Description : For a shortened vertical antenna, where should a loading coil be placed to minimize losses and produce the most effective performance? A. As low as possible on the vertical radiator B. Near the center of the vertical radiator C. As close to the transmitter as possible D. At a voltage node
Last Answer : B. Near the center of the vertical radiator
Description : Stacking elements in a transmitting antenna system A. increases the field strength at the receiving antenna B. increases the directivity of the transmitter antenna C. decrease the size of the lobe in the radiation pattern D. both A and B
Last Answer : D. both A and B
Description : A final amplifier of a radio transmitter draws 250 mA of plate current when the plate supply voltage is 1400 volts. If the plate circuit efficiency is 80% and the transmitter is connected to an antenna having a feed impedance of 70 ohms, ... at the feed-point? A. 4.0 A B. 2.2 A C. 1.25 A D. 2.0 A
Last Answer : D. 2.0 A
Description : How is it possible to lower the resonant frequency of Hertz dipole antenna? A. By reducing the frequency at the transmitter B. By connecting a capacitor in series with the antenna C. By the connecting a resistor in series with the antenna D. By connecting an inductor in series with the antenna
Last Answer : D. By connecting an inductor in series with the antenna
Description : If an antenna has a gain of 3 dB, it increases the output of the transmitter by A. 10,000 times B. 1000 times C. 100 times D. 1 million times
Last Answer : B. 1000 times
Description : In testing transmitter to prevent interfering with other stations, which type of antenna must be used? A. Void antenna B. Dummy antenna C. Hertzian antenna D. Isotropic antenna
Last Answer : B. Dummy antenna
Description : What is the effective radiated power of a repeater with 200 watts transmitter power output, 4 dB feline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 317 W B. 2000 W C. 126 W D. 260 W
Last Answer : A. 317 W
Description : What is the effective radiated power of a repeater with 120 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 601 W B. 240 W C. 60 W D. 379 W
Last Answer : C. 60 W
Description : What is the effective radiated power of a repeater with 100 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 10 dB antenna gain? A. 800 W B. 126 W C. 12.5 W D. 1260 W
Last Answer : B. 126 W
Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 6 dB antenna gain? A. 37.6 W B. 237 W C. 150 W D. 23.7 W
Last Answer : A. 37.6 W
Description : What is the effective radiated power of a repeater with 75 watts transmitter power output, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 10 dB antenna gain? A. 600 W B. 75 W C. 18.75 W D. 150 W
Last Answer : D. 150 W
Description : What is the effective radiated power of a repeater with 50 watts transmitter power output, 5 dB feedline loss, 4 dB duplexer and circulator loss, and 7 dB antenna gain? A. 300 W B. 315 W C. 31.5 W D. 69.9 W
Last Answer : C. 31.5 W
Description : What is the effective radiated power of a repeater with 50 watts transmitter power output \, 4 dB feedline loss, 3 dB duplexer and circulator loss, and 6 dB antenna gain? A. 158 W B. 39.7 W C. 251 W D. 69.9 W
Last Answer : B. 39.7 W
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 : If a transmission line has a power loss of 6 dB per 100 feet, what is the power at the feed point to the antenna at the end of a 200 foot transmission line fed by a 100 watt transmitter? A. 70 watts B. 50 watts C. 25 watts D. 6 watts
Last Answer : D. 6 watts
Description : A satellite transmitter operates at 4GHz with an antenna gain of 4dBi. The receiver 40000 km away has an antenna gain of 50 dBi. If the transmitter has a power of 8 W, find (ignoring feedline losses and mismatch) the EIRP in dBW. A. 50 B. 69 C. 49 D. 30
Last Answer : C. 49
Description : One of the following prevents a transmitter from emitting a signal that interferes with other stations on frequency during the test. A. Use of low height antenna B. Use of grounded antenna C. Use of dummy antenna D. Use of shielded antenna radiator
Last Answer : C. Use of dummy antenna
Description : The stability of transmitted signal from a simple Hartley oscillator single transmitter which is coupled to and antenna wire affected by ______. A. Chirping of oscillator B. Closer coupling between the oscillator and the antenna. C. Location of antenna D. Material of antenna
Last Answer : B. Closer coupling between the oscillator and the antenna.
Description : It is an average power of a radio transmitter supplied to the antenna transmission line taken during a long sufficient interval of time and compared with the lowest frequency encountered in the modulation ... operating conditions. A. Carrier power B. Rated power C. Mean power D. Peak envelop power
Last Answer : C. Mean power
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 : Determine the effective radiated power of 20 kW TV broadcast transmitter whose antenna has a field gain of 2. A. 40 kW B. 80,000 watts C. 40,000 watts D. 8,000 watts
Last Answer : B. 80,000 watts
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 : A transmitter supplies 8 kW to the antenna when it is unmodulated, determine the total radiated power when modulated at 90%. A. 5 kW B. 20 kW C. 15 kW D. 8.36 kW
Last Answer : D. 8.36 kW
Description : How can intermodulation interference between two transmitters in close proximity reduced or eliminated? A. Through installing a band-pass filter in the antenna feed line B. Through installing terminated circulator ... high driving power D. By installing a low-pass filter in the antenna feed line
Last Answer : A. Through installing a band-pass filter in the antenna feed line
Description : Referred to as a ferrite device that can be used in lieu of a duplexer to isolate a microwave transmitter and receiver when both are connected to the same antenna. A. Isolator B. Circulator C. Coupler D. Diode.
Last Answer : B. Circulator