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
Description : Which antenna is not grounded at one end? A. Hertz B. Marconi C. Dipole D. Whip
Last Answer : C. Dipole
Description : The effect of adding parasitic elements of a Hertz dipole is to A. make the antenna more omnidirectional B. reduce its resonant frequency C. increase the antenna’s power gain D. All of these
Last Answer : C. increase the antenna’s power gain
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 : If the length of a Hertz dipole is decreased A. its resonant frequency will be lowered its distributed inductance will be increased B. its distributed inductance will be decreased C. its ... frequency will be increased D. its distributed capacitance between the antenna and ground will be increased.
Last Answer : C. its resonant frequency will be increased
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 : Where do the maximum current and minimum voltage values on a resonant Hertz dipole exist? A. Center of the antenna B. Near the end of the antenna C. Near the center of the antenna D. Ends of the antenna
Last Answer : A. Center of the antenna
Description : Which is properly terminated antenna? A. Rhombic B. Hertz C. Marconi D. Dipole
Last Answer : A. Rhombic
Description : One ofthe followingis veryuseful as amultibandHFreceivingantenna.Thisisthe: a. conical horn b. folded dipole c. log periodic d. square loop
Last Answer : c. log periodic
Description : _____ is an antenna made up of a number of full wavelengths A. Elementary doublet B. Log-periodic C. Long wire D. Whip
Last Answer : C. Long wire
Description : One of the following is very useful as a multiband HF receiving antenna. A. Parabolic antenna B. Elementary doublet C. Log-periodic D. Square loop
Last Answer : C. Log-periodic
Description : ______ is an antenna array which is highly directional at right angles to the plane of the array? A. Broadside array B. End-fire array C. Turnstile array D. Log-periodic array
Last Answer : A. Broadside array
Description : All elements in a beam _____ antennas are in line A. collinear B. yagi C. broadside array D. log-periodic
Last Answer : A. collinear
Description : Modulation in which the modulated wave is always present. A. Carrier modulation B. Front-end C. Continuous modulation D. Log-periodic modulation
Last Answer : C. Continuous modulation
Description : It consists of a number of dipoles of equal size, equally spaced along a straight line with all dipoles fed in the same phase from the same source. A. Log-periodic antenna B. Yagi antenna C. End-fire array D. Broadside array
Last Answer : D. Broadside array
Description : The greatest induced EMF will occur in a straight wire moving at constant speed through a uniform magnetic field when the angle between the direction of the wire's motion and the direction of the magnetic field is w) 0 degrees x) 30 degrees y) 60 degrees z) 90 degrees
Last Answer : ANSWER: Z -- 90 DEGREES
Description : What is the relationship in degrees of the electrostatic and electromagnetic fields of an antenna? A. 0 degree B. 45 degrees C. 90 degrees D. 180 degrees
Last Answer : C. 90 degrees
Description : In shipboard satellite dish antennas system, azimuth is referred as the _______. A. 0 to 90 degrees B. Vertical aiming of the antenna C. North to East D. Horizontal aiming of the antenna
Last Answer : D. Horizontal aiming of the antenna
Description : In satellite communication, the Geostationary satellites are conveniently located with respect to the equator at _______. A. 45 degrees latitude B. 90 degrees latitude C. 0 degrees latitude D. 5 degrees latitude
Last Answer : C. 0 degrees latitude
Description : On meter length of wires carriers a constant current. The wire is bent to from a circular loop. The magnetic field at the centre of this loop is `B`.
Last Answer : On meter length of wires carriers a constant current. The wire is bent to from a circular loop. The magnetic field at ... B. `4B` C. `B/4` D. `16B`
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 : Which antenna does not use the ground? A. Marconi B. Yagi C. Hertz D. Rhombic
Last Answer : B. Yagi
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 : 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 : In what year did Hertz discover radio waves? A. 1844 B. 1873 C. 1887 D. 1895
Last Answer : C. 1887
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 : 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 : A loudspeaker cabinet has an internal volume of 5,184 in3 (84,950 cm3 ). It has a port area on the baffle of 50 in2 (322.58cm2 ) and a thickness of 0.70 in (18 mm). What is the Helmholtz resonance, in hertz, of this loudspeaker enclosure? A. 250 Hz B. 245 Hz C. 240 Hz D. 255 Hz
Last Answer : C. 240 Hz
Description : A speaker cabinet has an internal volume 84,950 cm3 . It has a port area on the baffle of 3,230 cm2 and baffle thickness of 19 mm. What is the Helmholtz resonance hertz of this speaker enclosure? A. 260 Hz B. 245 Hz C. 265 Hz D. 250 Hz
Last Answer : B. 245 Hz
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 meant by referring to electromagnetic waves as having circular polarization? A. The electric field is bent into a circular shape. B. The electric field rotates C. The electromagnetic wave continues to circle the earth D. The electromagnetic wave has been generated by a quad antenna
Last Answer : B. The electric field rotates
Description : What phenomenon causes the radio-path horizon distance to exceed the geometric horizon? A. E-layer skip. B. D-layer skip. C. Auroral skip. D. Radio waves may be bent.
Last Answer : D. Radio waves may be bent.
Description : Refers to a type of beam antenna which uses two or more straight elements arranged in line with each other. A. Dipole antenna B. Yagi antenna C. Whip antenna D. Rhombic antenna
Last Answer : B. Yagi antenna
Description : Which antenna is not a wideband? A. Discone B. Folded dipole C. Helical D. Marconi
Last Answer : D. Marconi
Description : The input terminal impedance at the center of a folded dipole antenna is A. 72 Ω B. 300 Ω C. 50 Ω D. 73 Ω
Last Answer : B. 300 Ω
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 : In horizontal-dipole antenna, the polarization is A. in the vertical direction B. in the horizontal direction C. circular D. measured at the center of the antenna
Last Answer : B. in the horizontal direction
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 : What is the capture area of a dipole operated at 75 MHz? A. 4 mm B. 2 m2 C. 2.088 m2 D. 4.088 m2
Last Answer : C. 2.088 m2
Description : The frequency of operation of a dipole antenna cut to a length of 3.4 m. A. 88 MHz B. 44 MHz C. 22 MHz D. 11 MHz
Last Answer : B. 44 MHz
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 : An antenna with unity gain A. Rhombic B. Half-wave dipole C. Isotropic D. Whip
Last Answer : C. Isotropic
Description : What is the theoretical gain of a Hertzian dipole? A. 1.76 dB B. 2.15 dB C. 3 dB D. 0 dB
Last Answer : A. 1.76 dB
Description : What is the radiation characteristic of a dipole antenna? A. Omnidirectional B. Bidirectional C. Unidirectional D. Hemispherical
Last Answer : B. Bidirectional
Description : Which antenna is a properly terminated? A. Marconi B. Rhombic C. Dipole D. Yagi-Uda
Last Answer : B. Rhombic
Description : A dipole antenna requires to be fed with 20 kW of power to produce a given signal strength to a particular distant point. If the addition of a reflector makes the same field strength available with an input power of 11kW ... Gain referred to this particular dipole). A. 4.75 B. 2.6 C. 1.81 D. 4.24
Last Answer : B. 2.6
Description : What is the gain of the Hertzian dipole over isotropic antenna? A. 1.64 dB B. 2.15 dB C. 1.76 dB D. 1.55 dB
Last Answer : C. 1.76 dB
Description : Which is a non-resonant antenna? A. Rhombic antenna B. Folded dipole C. End-fire array D. Yagi-Uda antenna
Last Answer : A. Rhombic antenna
Description : What antenna can be used to minimize the effect of Faraday rotation of polarization? A. Dipole B. Parabolic C. Helical D. Rhombic
Last Answer : C. Helical
Description : What is the end impedance of a half-wave dipole? A. 73 Ω B. 72 Ω C. 250 Ω D. 2500 Ω
Last Answer : D. 2500 Ω