CDC 3D153 v2 URE Flashcards
Equipment used for generating, amplifying, and transmitting RF carrier is collectively calleda. a receiver.b. an antenna.c. a transmitter.d. a transmission line.
c. a transmitter.
What basic receiver function involves having the transmitted electromagnetic wave pass through the receive antenna in such a manner as to induce a voltage in the antenna?a. Reproduction.b. Reception.c. Detection.d. Selection.
b. Reception.
The ability to reproduce the input signal accurately is the characteristics of the receiver’sa. fidelity.b. capacity.c. sensitivity.d. selectivity.
a. fidelity.
A combination of a transmitter and receiver that is built as a single unit and sharing common tuned circuits is called aa. transmitter.b. transceiver.c. receiver.d. coupler.
b. transceiver.
Which of the following cannot be performed by the transceiver’s computerized components and micro-circuitry?a. specific equipment faults.b. internal equipment tests.c. internal calibrations.d. repair itself.
d. repair itself.
A transmission line that consists of a center conductor placed inside a metal tube functioning as the outer tube is called aa. flexible coaxial cable.b. rigid coaxial cable.c. waveguide.d. twin lead.
b. rigid coaxial cable.
Which selection best describes the term “cutoff frequency” when discussing transmission line properties?XL = X_L XC= X_Ca. The frequency where XL becomes so low that the signal is shunted.b. The frequency where XC causes the signal to be shunted.c. The lowest frequency that the line can pass successfully.d. The frequency at which standing waves are maximum.
b. The frequency where XC causes the signal to be shunted..
Using figure 1–10, determine the wavelength if the frequency is changed from 150 MHz to 250 MHz.a. 12.0 meters.b. 3.0 meters.c. 1.5 meters.d. 1.2 meters.
d. 1.2 meters.
Using figure 1–10, determine the electrical length if the frequency is changed from 150 MHz to 250 MHz.a. 8.33 meters.b. 8.33 wavelengths.c. 83.3 meters.d. 83.3 wavelengths.
b. 8.33 wavelengths.
A nonresonant transmission line is a linea. having reflected waves.b. having no reflected waves.c. with maximum voltage across its open termination.d. with maximum voltage across its shorted termination.
b. having no reflected waves.
If a transmission line is terminated in a short,a. current is at maximum and voltage at minimum at the termination.b. current is at minimum and voltage at maximum at the termination.c. there would be a nominal amount of signal gain.d. the line would be nonresonant.
a. current is at maximum and voltage at minimum at the termination.
In a basic communication system, what converts radio frequency (RF) energy’s current oscillation into electric and magnetic fields of force?a. Antenna.b. Coupler.c. Transmitter.d. Transmission lines.
a. Antenna.
The concept that alternating current (AC) changes in magnitude and reverses its direction during each cycle isa. an unproven hypothesis.b. the definition of propagation.c. what makes radio transmission possible.d. what led to the discovery of direct current.
c. what makes radio transmission possible.
If the electric field component travels in a plane perpendicular to the Earth’s surface, the radio wave isa. magnetically polarized.b. horizontally polarized.c. circularly polarized.d. vertically polarized.
d. vertically polarized.
What types of polarization do satellite terminals transmit and receive?a. Transmit horizontal and receive vertical polarizations.b. Transmit vertical and receive horizontal polarizations.c. Transmit right hand and receive left hand circular polarizations.d. Transmit left hand and receive right hand circular polarizations.
c. Transmit right hand and receive left hand circular polarizations.
What measurement is used to determine whether an antenna is resonant at a particular frequency?a. Distortion.b. Standing wave ratio.c. Signal-to-noise ratio.d. Percent of modulation.
b. Standing wave ratio.
The ability of an antenna to both receive and transmit equally well is known as theantenna’sa. bandwidth.b. resonance.c. reciprocity.d. effectiveness.
c. reciprocity.
The standard used to measure the radiating effectiveness (gain) of an antenna system is thea. Marconi antenna.b. isotropic antenna.c. Hertz antenna.d. whip antenna.
b. isotropic antenna.
What does the effectiveness of an entire transmitting and receiving system depend largely upon?a. Impedance matching.b. Antenna distance.c. Antenna properties.d. Line characteristics.
a. Impedance matching.
Which antenna radiates radio energy in a circular pattern?a. Omnidirectional.b. Unidirectional.c. Bidirectional.d. Directional.
a. Omnidirectional.
Which antenna type is usually used on long-range, point-to-point circuits where the concentrated radio energy is needed for circuitry reliability?a. Omnidirectional.b. Unidirectional.c. Bidirectional.d. Circular.
b. Unidirectional.
Ungrounded lengths of wire specifically designed to be either a half-wavelength or more than full wavelength long is called aa. reflector.b. Hertz antenna.c. Marconi antenna.d. vertical monopole.
b. Hertz antenna.
A long-wire’s takeoff angle depends on the antenna’sa. length.b. directivity.c. front-to-back ratio.d. standing wave ratio.
a. length.
All antennas used in satellite communications are designed to bea. circular directional.b. omnidirectional.c. bidirectional.d. directional.
d. directional.