Description : A 1 Mhz carrier is amplitude modulated by a pure 200-Hz audio test tone. Which of the following combinations of frequencies represent the total content of the AM signal? A. 1 MHz and 200 Hz B. 1 MHz and 1000.2 kHz C. 999.8 kHz, 1000 kHz, and 1000.2 kHz D. 999.8 kHz and 1000.2 kHz
Last Answer : C. 999.8 kHz, 1000 kHz, and 1000.2 kHz
Description : Increasing the resonant frequency of an end-fed Marconi antenna can be done by A. adding a capacitor in series and reducing the physical length B. adding an inductor in series C. adding an inductor in series D. All of these
Last Answer : A. adding a capacitor in series and reducing the physical length
Description : In the case if Marconi antenna, the actual length if the radiating element is A. one-half wavelength B. one-quarter wavelength C. one wavelength D. one-eight wavelength
Last Answer : B. one-quarter wavelength
Description : What is the maximum line-of-sight distance between a paging antenna 250 ft high and a pager receiver 3.5ft of the ground? A. 25 km B.25mi C. 70.73 km D. 70.73 mi
Last Answer : B.25mi
Description : What is the typical frequency used for communicating to submerged submarines? A. 100 Hz B. 500 Hz C. 4 kHz D. 200 Hz
Last Answer : A. 100 Hz
Description : Frequencies above ______ kHz, are referred to as the radio frequencies. A. 20 B. 2 C. 10 D. 200
Last Answer : A. 20
Description : What is the estimated medium wind loading in the Philippines for antenna tower design? A. 300 kph B. 100 kph C. 200 kph D. 250 kph
Last Answer : C. 200 kph
Description : What is the estimated medium wind loading in the Philippines for antenna tower design? A. 200 kph B. 250 kph C. 300 kph D. 100 kph
Last Answer : A. 200 kph
Description : Which antenna does not use the ground? A. Marconi B. Yagi C. Hertz D. Rhombic
Last Answer : B. Yagi
Description : Which antenna is not grounded at one end? A. Hertz B. Marconi C. Dipole D. Whip
Last Answer : C. Dipole
Description : Which antenna is not a wideband? A. Discone B. Folded dipole C. Helical D. Marconi
Last Answer : D. Marconi
Description : When a capacitor is connected in series with a Marconi antenna? A. Antenna open circuit stops transmission B. An inductor of equal value must be added C. No change occurs to antenna D. Antenna resonant frequency increases
Last Answer : D. Antenna resonant frequency increases
Description : A theoretical reference antenna that provides a comparison for antenna measurements. A. Marconi antenna B. Isotropic radiator C. Yagi-Uda array D. Whip antenna
Last Answer : B. Isotropic radiator
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 one-quarter wavelength shunt-fed vertical Marconi antenna A. has maximum radiation in a vertical direction B. must have a horizontal receiving antenna for the best reception C. must use a receiving antenna for the best reception D. must have a vertical receiving antenna for the best reception
Last Answer : D. must have a vertical receiving antenna for the best reception
Description : The current maximum in a Marconi antenna is found at A. the base of the antenna B. the center of the antenna C. some point between the base and the center of the antenna D. the top of the antenna
Last Answer : A. the base of the antenna
Description : An antenna which is one-tenth wavelength long A. Hertzian dipole B. Loop antenna C. Marconi antenna D. Elementary doublet
Last Answer : D. Elementary doublet
Description : Which antenna is a properly terminated? A. Marconi B. Rhombic C. Dipole D. Yagi-Uda
Last Answer : B. Rhombic
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 : Which of the following antennas require good grounding? A. Yagi antenna B. Hertz antenna C. Marconi antenna D. Isotropic antenna
Last Answer : C. Marconi antenna
Description : Which of the following antennas receives signals equally well from all directions in a horizontal plane? A. Hetz antenna B. Vertical Marconi antenna C. Yagi antenna D. Helical antenna
Last Answer : B. Vertical Marconi antenna
Description : This is a flexible vertical rod antenna commonly used on mobiles. A. Marconi B. Hertz C. Whip D. Ground plane
Last Answer : C. Whip
Description : Which is properly terminated antenna? A. Rhombic B. Hertz C. Marconi D. Dipole
Last Answer : A. Rhombic
Description : ECE Board Exam March 1996 A type of an underground antenna is a/an __________ antenna. A. Hertz B. isotropic C. parabolic D. Marconi
Last Answer : A. Hertz
Description : What is the required quality factor for an SSB filter with the following data: center frequency= 1 MHz, the desired attenuation level of the unwanted sideband= 80 dB and the separation between sidebands= 200 Hz? A. 1,250 B. 12,500 C. 125,000 D. 25,000
Last Answer : C. 125,000
Description : What is antenna bandwidth? A. Antenna length divided by the number of elements B. The angle between the half-power radiation points C. The angle formed between two imaginary lines drawn through D. The frequency range over which an antenna can be expected to operate satisfactorily
Last Answer : D. The frequency range over which an antenna can be expected to operate satisfactorily
Description : A Hertz antenna is operating on a frequency of 2182 kHz and consists of a horizontal wire that is hanged between two towers. What is the frequency of its third harmonic? A. 727 kHz B. 6546 kHz C. 436 kHz D. 6.546 kHz
Last Answer : B. 6546 kHz
Description : What is the channel spacing for SITOR frequencies? A. 500 Hz B. 170 Hz C. 300 Hz D. 3 kHz
Last Answer : A. 500 Hz
Description : What is the channel spacing for MF-HF voice frequencies? A. 2.8 kHz B. 500 Hz C. 3.5 kHz D. 3 kHz
Last Answer : D. 3 kHz
Description : How many voice signals (4 kHz max.) would fit into a 5 MHz spectrum? A. 1250 B. 500 C. 1000 D. 1500
Last Answer : A. 1250
Description : What is the channel bandwidth of a standard analogue telephone system? A. 300-500 Hz B. 1200 kHz C. 100-300 Hz D. 300-3400 Hz
Last Answer : D. 300-3400 Hz
Description : An amplifier operating over the frequency range of 455 to 460 kHz has a 200 kΩ input resistor. What is the RMS noise voltage at the input to this amplifier if the ambient temperature is 17˚C ? A. 40 µV B. 4.0 µV C. 400 µV
Last Answer : B. 4.0 µV
Description : Industrial noise frequency is between _____. A. 0 to 10 KHz B. 160 MHz to 200 MHz C. 15 to 160 MHz D. 200 to 3000 MHz
Last Answer : C. 15 to 160 MHz
Description : What is the approximate bandwidth of an FM system with 10 kHz of modulating frequency and a 150 kHz of frequency deviation? A. 300 kHz B. 320 kHz C. 150 kHz D. 200 kHz
Last Answer : B. 320 kHz
Description : In acoustics, if the volume of the room is 200 m3 then at what frequency the coefficient of absorption is measured? A. 120 kHz B. 120 Hz C. 100 Hz D. 150 Hz
Last Answer : B. 120 Hz
Description : How wide is the spectrum bandwidth of a single GSM carrier? A. 100 kHz B. 200 kHz C. 50 kHz D. 16 kHz
Last Answer : B. 200 kHz
Description : Industrial noise frequency is between _________. A. 200 to 3000 Mhz B. 15 to 160 Mhz C. 0 to 10 Khz D. 20 Ghz
Last Answer : B. 15 to 160 Mhz
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 : An aircraft is travelling at 100kts forward speed on a 3° glidescope. What is its rate of descent? a. 500 ft/min b. 300 ft/min c. 250 ft/min d. 600 ft/min
Last Answer : a. 500 ft/min
Description : Which of the following describes a TDM frame? A. A 250-μs frame B. A 125-μs frame C. A 500-μs frame D. A 60-μs frame
Last Answer : B. A 125-μs frame
Description : What is the bandwidth available in the commercial C-band? A. 1000 MHz B. 36 MHz C. 250 MHz D. 500 MHz
Last Answer : D. 500 MHz
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 : If a carrier wave of 1000 kHz is used to carry the signal, the length of transmitting antenna will be equal to _______. (1) 300 m (2) 30 m (3) 3 m (4) 0.3 m
Last Answer : (1) 300 m Explanation: h = 3 × 108/106 = 300 m
Description : The electromagnetic radiation theory was profounded by A. Sir Edward Appleton B. Guglielmo Marconi C. Heinrich Hertz D. James C. Maxwell
Last Answer : D. James C. Maxwell
Description : What is the frequency range of an aircraft’s Very High Frequency (VHF) communications? A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz) B. 108.000 MHz to 117.95 MHz C. 329.15 MHz to 335.00 MHz D. 2.0000 MHz to 29.999 MHz
Last Answer : A. 118.000 MHz to 136.975 MHz (worldwide up to 151.975 MHz)
Description : The Federal Communications Commission (FCC) allows ______ kHz for each FM station. A) 20 B) 100 C) 200 D) none of the above
Last Answer : 100
Description : The power fed to a two-bay turnstile antenna is 100 watts. If the antenna has a 2 dB power gain, what is the effective radiated power? A. 317 watts B. 158 watts C. 200 watts D. 400 watts
Last Answer : B. 158 watts
Description : If 4 kW in antenna produces 50 μV/m in a receiving antenna, a 15 kW will produce _____. A. 200 μV/m B. 10 μV/m C. 100 μV/m D. 20 μV/m
Last Answer : C. 100 μV/m
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