# Set 2 Vol 2 Communication

30 Questions | Total Attempts: 34  Settings  • 1.
In a basic communication system, this is used to convert radio frequency (RF) current oscillation into electric and magnetic fields of force
• A.

Antenna

• B.

Transmitter

• C.

Coupler

• D.

Transmission lines

• 2.
The concept where alternating current (AC) changes in magnitude, and reverses its direction during each cycle, is
• A.

An unproven hypothesis

• B.

The definition of propagation

• C.

• D.

What led to the discovery of direct current (DC)

• 3.
At which point do magnetic fields around a wire no longer have time to collapse completely between alternations?
• A.

60 cycles per second (cps)

• B.

120 cps

• C.

10,000 cps

• D.

15,000 cps

• 4.
In radio-wave creation, which type of field detaches from the antenna and travels through space at great distances?
• A.

• B.

Induction

• C.

Gravitational

• D.

Electromotive

• 5.
Which types of polarization do most satellite communication terminals transmit and receive?
• A.

Transmit horizontal and receive vertical polarizations

• B.

Transmit vertical and receive horizontal polarizations

• C.

Transmit right-hand circular and receive left-hand circular polarizations

• D.

Transmit left-hand circular and receive right-hand circular polarizations

• 6.
A resonant antenna effectively radiates a radio signal for frequencies close to its designed frequency. Which percentage range, plus or minus, is it usually within?
• A.

1

• B.

2

• C.

3

• D.

4

• 7.
The design frequency of a resonant antenna is 10 megahertz (MHz). What will be its frequency range?
• A.

8–10 MHz

• B.

9–11 MHz

• C.

9.5–10.5 MHz

• D.

9.8–10.2 MHz

• 8.
The lowest frequency at which an antenna resonates is known as its
• A.

Standing wave

• B.

Fundamental

• C.

Resonation

• D.

Primary.

• 9.
The ability of an antenna to both receive and transmit equally well is known as the antenna’s
• A.

Bandwidth

• B.

Resonance

• C.

Reciprocity

• D.

Effectiveness

• 10.
This matching device is inserted to make a transmitter “think” it is connected to a low standing-wave ratio (SWR) antenna
• A.

Stub

• B.

Balun

• C.

Coupler

• D.

Terminating resistor

• 11.
This matching device would be used to connect a 52-ohms RG–213 cable to an antenna with an impedance of 600-ohms.
• A.

Balun.

• B.

Coupler

• C.

Reflector

• D.

Terminating resistor

• 12.
Which type of antenna radiates radio energy equally well in all directions?
• A.

Omni-directional

• B.

Uni-directional

• C.

Bi-directional

• D.

Directional

• 13.
Add this device to make a long-wire antenna more directional
• A.

Stub

• B.

Balun

• C.

Coupler

• D.

Terminating resistor

• 14.
Beam width of a directive antenna is measured at the
• A.

Quarter-power point

• B.

Half-power point

• C.

Three-quarters power point

• D.

Maximum value point

• 15.
A dipole or long-wire antenna is an example of a
• A.

Whip antenna

• B.

Hertz antenna

• C.

Marconi antenna

• D.

Vertical monopole

• 16.
This is one of the simplest and most functional antennas in use
• A.

Quarter-wave vertical

• B.

Half-wave dipole

• C.

Inverted-V

• D.

GRA–4

• 17.
The minimum length of a long-wire antenna is
• A.

One-quarter wavelength

• B.

One-half wavelength

• C.

One wavelength

• D.

Two wavelengths

• 18.
You should use this type of antenna to communicate over the horizon to an amphibious ship on the move or to a station up to 450 kilometers away
• A.

Near-vertical incidence sky-wave

• B.

Helical

• C.

Inverted-V

• D.

Inverted-L

• 19.
How are most antennas designed that are used in satellite communications?
• A.

Circular-directional

• B.

Omni-directional

• C.

Bi-directional

• D.

Directional

• 20.
Which type of polarization is used to radiate a signal using a helical satellite antenna?
• A.

Horizontal

• B.

Vertical

• C.

Circular

• D.

Linear

• 21.
This type of antenna is used to transmit and receive microwave signals
• A.

Horn

• B.

Whip

• C.

Helical

• D.

Log-periodic

• 22.
Where are aircraft antennas normally housed?
• A.

Inside nonconductive radomes outside or flush with the fuselage

• B.

Inside conductive radomes outside or flush with the fuselage

• C.

Outside nonconductive radomes outside the fuselage

• D.

Inside conductive radomes flush with the fuselage

• 23.
At which vertical angles should the multi-hop, long-distance transmission be used in airborne antenna applications for frequencies in the upper portion of the high-frequency (HF) band?
• A.

90 and 180 degrees

• B.

60 and 90 degrees

• C.

30 and 60 degrees

• D.

5 and 30 degrees

• 24.
This is the best way to orient line-of-sight (LOS) antennas
• A.

Toward the true north bearing

• B.

Away from the receiving station

• C.

Away from the magnetic north bearing

• D.

In a straight path to the receiving station

• 25.
When siting a radio station, which type of foliage would have a more adverse effect on radio-wave propagation?
• A.

• B.

Evergreen trees

• C.

Swamp grass

• D.

Sagebrush

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