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 : In order to get maximum radiation to all surrounding points in the horizontal plane, the antenna used is a A. vertical loop B. vertical quarter-wavelength rod C. array which includes parasitic elements D. a horizontal Hertz dipole
Last Answer : B. vertical quarter-wavelength rod
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 : Which of the following antennas receive signals in the horizontal plane equality well from all directions? A. Horizontal Hertz antenna B. Vertical loop antenna C. Vertical Yagi antenna D. A vertical antenna which is a quarter-wavelength long
Last Answer : D. A vertical antenna which is a quarter-wavelength long
Description : What is the seventh harmonic of a 100 MHz quarter wavelength antenna? A. 14.28 MHz B. 107 MHz C. 149 MHz D. 700 MHz
Last Answer : D. 700 MHz
Description : What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.68 to 30 MHz? A. 19.26 B. 5.6 C. 17.82 D. 16.97
Last Answer : B. 5.6
Description : What is the actual length in feet of a one-quarter wavelength of a coax with a velocity factor of 0.695 at 45 MHz? A. 17.82 B. 19.26 C. 16.28 D. 16.97
Last Answer : C. 16.28
Description : The antenna effective height is ____ to ____ of the actual height. A. ½ to 2/3 B. ½ to ¾ C. ¼ to 2/3 D. ¼ to ¾
Last Answer : A. ½ to 2/3
Description : What is the gain of an antenna over a half-wavelength dipole when it has 6 dB gain over an isotropic radiator? A. 6.0 dB B. 8.1 dB C. 3.9 dB D. 10.0 dB
Last Answer : C. 3.9 dB
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 actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.59 at 26 MHz? A. 11.16 B. 40.29 C. 42.46 D. 46.28
Last Answer : A. 11.16
Description : What is the actual length in feet of a one-half wavelength of a coax with a velocity factor of 0.63 at 28 MHz? A. 44.28 B. 43.46 C. 11.07 D. 46.27
Last Answer : C. 11.07
Description : Most mobile satellite array uses ___________ in transforming 50 to 150 Ω impedance. A. stub B. balun C. quarter-wavelength transformer D. microstrip tapers.
Last Answer : C. quarter-wavelength transformer
Description : What is the reactance property at the input of a shorted quarter wavelength line? A. A parallel LC circuit B. A pure inductive reactance C. A series LC circuit D. A pure capacitive reactance
Last Answer : A. A parallel LC circuit
Description : What is the input impedance of a transmission line if its characteristic impedance is 300 Ω and the load is 600 Ω? Assume a quarter wavelength section only. A. 150 kΩ B. 150 mΩ C. 150 Ω D. 2 Ω
Last Answer : C. 150 Ω
Description : What would be the physical length of a tpical coaxial transmission line that is electrically one-quarter wavelength long at 14.1 MHz? A. 20 meters B. 3.51 meters C. 2.33 meters D. 0.25 meter
Last Answer : B. 3.51 meters
Description : A quarter wavelength devices made of crystalline calcite that changes polarization in the optic fiber communication. A. Isolator B. Retarder C. Polarizer D. Filters
Last Answer : B. Retarder
Description : What is the usual electrical length of a driven element in an HF beam antenna? A. ¼ wavelength B. ¾ wavelength C. ½ wavelength D. 1 wavelength
Last Answer : C. ½ wavelength
Description : If an antenna is too short for the wavelength being used, the effective length can be increased by adding: A. capacitance in series B. inductance in series C. resistance in parallel D. resistance in series
Last Answer : B. inductance in series
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 : A transmitted signal 5 meters in wavelength is received by an antenna coil having a 50-Ω resistance and a 0.01 H inductance. What is the capacitance of the tuner shunting the antenna coil at this point? A. 0.704 fF B. 0.704 μF C. 0.704 nF D. 0.704 mF
Last Answer : A. 0.704 fF
Description : Where are the current nodes in a half-wave antenna? A. At the ends B. At the center C. Three-quarters of the way from the feed point toward the end D. One-half of the way from the feed point toward the end
Last Answer : A. At the ends
Description : Where are the voltage nodes in a half-wave antenna? A. At the ends B. Three-quarters of the way from the feed point toward the end C. One-half of the way from the feed point toward the end D. At the feed point
Last Answer : D. At the feed point
Description : In a Young's double-slit experiment the center of a bright fringe occurs wherever waves from the slits differ in the distance they travel by a multiple of: A. a fourth of a wavelength B. a half a wavelength C. a wavelength D. three-fourths of a wavelength
Last Answer : C. a wavelength
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 : Factors that determine the radiation resistance of an antenna A. Transmission line length and height of antenna B. The location of the antenna with respect to nearby objects C. It is a constant for all antennas since it is physical D. Sunspot activity and the time of day
Last Answer : B. The location of the antenna with respect to nearby objects
Description : Top loading is used in an antenna in order to increase its ______. A. practical height B. beamwidth C. effective height D. input capacitance
Last Answer : C. effective height
Description : For a space wave transmission, the radio horizon distance of a receiving antenna with a height of 64 meters is approximately A. 8 km B. 32 km C. 64 km D. 256 km
Last Answer : B. 32 km
Description : The angle of elevation of the antenna beam is 20°. Calculate the transmission-path distance for an ionospheric transmission that utilizes a layer of virtual height 200 km. Use flat-earth approximation. A. 966 km B. 2100 km C. 1100 km D. 405 km
Last Answer : C. 1100 km
Description : A receiver is located 64 km from a space wave transmitting antenna that is 100 meters high. Find the required height of the receiving antenna. A. 36 meters high B. 64 meters high C. 100 meters high D. 182.25 meters high
Last Answer : A. 36 meters high
Description : For a space wave transmission, the radio horizon distance of a transmitting antenna with a height of 100 meters is approximately: A. 10 km B. 40 km C. 100 km D. 400 km
Last Answer : B. 40 km
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 advantage of periscope antenna in microwave A. Minimize interference to and from other neighboring stations B. Shorten waveguide link C. Reduce tower height D. All of these
Last Answer : B. Shorten waveguide link
Description : Top loading is used in an antenna in order to increase its ___________. A. input capacitance B. beamwidth C. bandwidth D. effective height
Last Answer : D. effective height
Description : What height of an ionized layer is determined from the time interval between the transmitted signal and the ionospheric echo at vertical incidence? A. Virtual height B. Apparent height C. Actual height D. Effective height
Last Answer : A. Virtual height
Description : Two light rays will interfere constructively with maximum amplitude if the path difference between them is: w) one wavelength x) one-half wavelength y) one-quarter wavelength z) one-eighth wavelength
Last Answer : ANSWER: W -- ONE WAVELENGTH
Description : Width measured in degrees of a major lobes between end of the love at which the relative power is one half (-3dB) its value from the peak of the lobe. A. Bandwidth B. Wavelength C. Radiation D. Beamwidth
Last Answer : D. Beamwidth
Description : The antenna efficiency of an HF grounded vertical antenna can be made comparable to that of a half-wave antenna A. By installing a good ground radial system B. By isolating the coax shield from ground C. By shortening the vertical D. By lengthening the vertical
Last Answer : A. By installing a good ground radial system
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 : An antenna with unity gain A. Rhombic B. Half-wave dipole C. Isotropic D. Whip
Last Answer : C. Isotropic
Description : _____ is an antenna with a number of half-wave antenna on it. A. Antenna array B. Tower C. Omni-directional D. Rhombic
Last Answer : A. Antenna array
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 : At the ends of a half-wave antenna, what values of current and voltage exist compared to the remainder of the antenna? A. Minimum voltage and minimum current B. Equal voltage and current C. Minimum voltage and maximum current D. Maximum voltage and minimum current.
Last Answer : D. Maximum voltage and minimum current.
Description : Where the voltage node of a half-wave antenna does exists? A. At feed point B. Near the center C. At center D. Near the feed point
Last Answer : A. At feed point
Description : What is meant by the term antenna bandwidth A. Antenna length divided by the number of elements. B. The angle between the half-power radiation points C. The frequency range over which and antenna ... perform well D. The angle formed between two imaginary line drawn through the ends of the elements
Last Answer : C. The frequency range over which and antenna can be expected to perform well
Description : How can the antenna efficiency of an HF grounded vertical antenna be made comparable to that of a half-wave antenna? A. By lengthening the vertical B. By installing a good ground radial system C. By shortening the vertical D. By isolating the coax shield from ground
Last Answer : B. By installing a good ground radial system
Description : The product of the power supplied to the antenna and its gain relative to a half-wave dipole in a given direction. A. Peak envelope power B. ERP C. Rated power D. Carrier power’
Last Answer : B. ERP
Description : Unity gain antenna A. Isotropic B. Rhombic C. Half-wave dipole D. Dummy
Last Answer : A. Isotropic
Description : A type of array antenna which consists of one half-wave driven dipole, one reflector and one director A. Hertzian dipole B. Yagi-uda C. Broadside collinear D. Log periodic dipole array
Last Answer : B. Yagi-uda