M2 B2

Question 1

Which US government agency divides the radio frequency spectrum into different bands?

Answer 1

Federal Communications Commission (FCC)

Question 2

High-frequency (HF) transmissions are normally conducted in which two operating modes?

Answer 2

SSB and ISB

Question 3

Which frequency band is most susceptible to jamming?

Answer 3

High frequency (HF)

Question 4

The ability of a receiver to reproduce the signal of a very weak station is characteristic of a receiver’s

Answer 4

sensitivity

Question 5

The ability of a receiver to reproduce the input signal accurately is characteristic of its

Answer 5

fidelity

Question 6

A combination transmitter and receiver, built as a single unit and shares common tuned circuits, is called a

Answer 6

transceiver

Question 7

Conductor material resistance in a transmission line leads to this type of loss

Answer 7

Copper loss

Question 8

The amount of skin-effect loss is directly proportional to the

Answer 8

frequency

Question 9

Leakage loss in a transmission line is minimized by using a

Answer 9

very high-resistance dielectric

Question 10

A transmission line that consists of a center conductor, placed inside a rigid metal tube that functions as the outer shield, is called

Answer 10

rigid coaxial cable

Question 11

A waveguide is a type of transmission line that you would use

Answer 11

when the frequencies are so high that their wavelength is miniscule

Question 12

All statements concerning waveguides are true except

Answer 12

their outer surface will arc from being very slightly damaged

Question 13

Which two transmission line properties determine its characteristic impedance (ZO)?

Answer 13

Inductance and capacitance

Question 14

This is the correct statement concerning a wavelength

Answer 14

Wavelength is inversely related to frequency.

Question 15

Determine the wavelength of a 250 megahertz (MHz) signal

Answer 15

1.2 meters

Question 16

A nonresonant transmission line is one with

Answer 16

no reflected waves

Question 17

When discussing resonant and nonresonant transmission lines

Answer 17

maximum power transfer results from a nonresonant line

Question 18

This will likely result if a transmission line is terminated in an open

Answer 18

Signal loss would be significant

Question 19

Direct waves are radio waves that travel

Answer 19

through the air in a straight line from transmitter to receiver

Question 20

Radio waves that travel near the Earth’s surface are called

Answer 20

ground waves

Question 21

The Earth’s conductivity is determined by the type of

Answer 21

soil and water in the propagation path

Question 22

This term is used to describe radio waves that bend as they travel from one medium to another that has different density

Answer 22

Refraction

Question 23

The refractive index of air depends on moisture

Answer 23

atmospheric pressure, and temperature

Question 24

When comparing the radio and optical horizons, which one is farther away and by what percentage?

Answer 24

Radio, 15

Question 25

Which process permits communication in shadow regions behind obstacles?

Answer 25

Diffraction

Question 26

Which frequency range will show little effect from precipitation?

Answer 26

High frequency (HF)

Question 27

Line-of-sight (LOS) radio waves that are guided through the air between two layers of the atmosphere are known as

Answer 27

ducting

Question 28

Which condition gives sky-wave propagation its ability to communicate beyond the optical line-of-sight (LOS)?

Answer 28

Refraction

Question 29

The angle at which a radio wave enters the ionosphere is known as the

Answer 29

angle of incidence

Question 30

There are several critical sky-wave propagation angles and frequencies. Radio waves that angle too low are

Answer 30

absorbed before refraction occurs

Question 31

In sky-wave propagation, frequencies higher than the critical frequency are

Answer 31

passed into space

Question 32

The term frequency of optimum transmission (FOT) is also referred to as the

Answer 32

optimum traffic frequency

Question 33

In sky- and ground-wave propagation, the area of silence where no signals are received is known as the

Answer 33

skip zone

Question 34

This occurs when a transmitted signal travels over two or more separate paths during transmission

Answer 34

Multipathing

Question 35

How many layers make up the Earth’s atmosphere?

Answer 35

5

Question 36

This occurs when high-energy ultraviolet light waves from the sun enter the ionospheric region of the atmosphere and strike the gas atoms

Answer 36

Ionization

Question 37

The atmospheric recombination process is dependent on the

Answer 37

time of day (TOD)

Question 38

Which layer of the ionosphere is most important for high-frequency (HF) communications?

Answer 38

F

Question 39

During which season do we have the wider range of critical frequencies and less absorption of all frequencies?

Answer 39

Winter

Question 40

As ionospheric solar variations, sunspots are disturbances that appear and disappear

Answer 40

on the sun's surface

Question 41

On which regular ionospheric variation do sunspots occur?

Answer 41

11-year cycle

Question 42

In a basic communication system, this is used to convert radio frequency (RF) current oscillation into electric and magnetic fields of force.

Answer 42

Antenna

Question 43

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

Answer 43

what makes radio transmission possible

Question 44

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

Answer 44

10,000 cps

Question 45

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

Answer 45

Radiation

Question 46

Which types of polarization do most satellite communication terminals transmit and receive?

Answer 46

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

Question 47

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?

Answer 47

2

Question 48

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

Answer 48

9.8 - 10.2 MHz

Question 49

The lowest frequency at which an antenna resonates is known as its

Answer 49

fundamental

Question 50

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

Answer 50

reciprocity

Question 51

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

Answer 51

Coupler

Question 52

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

Answer 52

Balun

Question 53

Which type of antenna radiates radio energy equally well in all directions?

Answer 53

Omni-directional

Question 54

Add this device to make a long-wire antenna more directional

Answer 54

Terminating resistor

Question 55

Beam width of a directive antenna is measured at the

Answer 55

half-power point

Question 56

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

Answer 56

Hertz antenna

Question 57

This is one of the simplest and most functional antennas in use

Answer 57

Half-wave dipole

Question 58

The minimum length of a long-wire antenna is

Answer 58

one wavelength

Question 59

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

Answer 59

Near-vertical incidence sky-wave

Question 60

How are most antennas designed that are used in satellite communications?

Answer 60

Directional

Question 61

Which type of polarization is used to radiate a signal using a helical satellite antenna?

Answer 61

Cicular

Question 62

This type of antenna is used to transmit and receive microwave signals

Answer 62

Horn

Question 63

Where are aircraft antennas normally housed?

Answer 63

Inside NONCONDUCTIVE radomes outside or flush with the fuselage.

Question 64

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?

Answer 64

5 and 30 degrees

Question 65

This is the best way to orient line-of-sight (LOS) antennas

Answer 65

In a straight path to the receiving station

Question 66

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

Answer 66

Broadleaf tree

Question 67

This has the greatest effect on an antenna’s radiation pattern

Answer 67

Earth

Question 68

This is one fundamental rule about camouflage

Answer 68

Straight lines are obvious

Question 69

This is the most effective type of antennas in mountainous terrain that has a mountain between you and the distant end

Answer 69

Near-vertical incidence sky-wave

Question 70

Which electronic warfare (EW) component responds to a tasking to search for, intercept, identify, and locate intentional and unintentional sources of radiated energy?

Answer 70

Support

Question 71

Electromagnetic (EM) deception, as it applies to electronic warfare (EW), is

Answer 71

conveying misleading information to an enemy through the deliberate radiation of EM energy

Question 72

In frequency-hopping (FH) operations, the interval at which each transmitter remains on a given frequency for a specific time is known as

Answer 72

dwell time

Question 73

Which type of hopping-rate category changes frequencies approximately 100 times per second?

Answer 73

Medium

Question 74

What does the term “ICOM” indicate?

Answer 74

Integrated communications security

Question 75

Which statement best identifies the requirements for two transceivers to establish HAVE QUICK (HQ) communications?

Answer 75

They must have the same word of day (WOD) and time of day (TOD)

Question 76

How long is each word-of-day (WOD) used with the HAVE QUICK II (HQII) communications multiple word-of-day (MWOD)?

Answer 76

24 hours

Question 77

Which tactical data link (TDL) is a secure, full-duplex, point-to-point digital data link that uses satellite, microwave, or terrestrial cable, as opposed to a modulated waveform, to transmit data?

Answer 77

Link 11b

Question 78

Which multiple channel access method eliminates the requirement for a net control station (NCS) in the joint tactical information distribution system (JTIDS) by providing node-less communications network architecture?

Answer 78

Time division

Question 79

The Air Force integrates with modified close air support aircraft with digitized battlefield information using this type of network.

Answer 79

Situation awareness data link (SADL)

Question 80

Which type of advanced waveform was designed to operate on manned, vehicular-based communication systems?

Answer 80

Wideband networking

Question 81

Which type of advanced waveform enables data and imagery situational awareness and provides enhanced combat effectiveness?

Answer 81

Soldier radio

Question 82

In high-frequency (HF) communications, your station’s automatic link establishment (ALE) self-address is the address

Answer 82

the user programmed for his or her station

Question 83

This is the simplest form of an automatic link establishment (ALE) call

Answer 83

Individual

Question 84

Which automatic link establishment (ALE) call option lets you call a predefined group of stations with a single shared address, and requires them to respond, one at a time, in a predefined order?

Answer 84

Net

Question 85

Where is the primary high frequency global communications system (HFGCS) network control station located?

Answer 85

Andrews AFB, Maryland

Question 86

This is not a major network within the Military Auxiliary Radio Service (MARS)

Answer 86

Ultra-high frequency (UHF) network

Question 87

The process of unscrambling encrypted information so that it is intelligible is known as

Answer 87

Decryption

Question 88

Which type of cryptographic algorithm permits the encryption key to be public?

Answer 88

Asymmetric

Question 89

Which secure communications device operates by simply sliding the key tape into the reader?

Answer 89

KOI-18

Question 90

The common name for the method of changing encryption keys over the radio channel in a two-way radio system is called

Answer 90

over-the-air-rekeying (OTAR)

Question 91

Which type of conventional land mobile radio (LMR) device maximizes the communications distance between lower-powered equipment items?

Answer 91

Repeater

Question 92

In a land mobile radio (LMR) repeater system, a device that separates and isolates the incoming receive signal from the outgoing transmit signal and vice versa is known as a

Answer 92

duplexer

Question 93

Which type of site configuration was designed to provide coverage for a small geographical area?

Answer 93

Single-site

Question 94

This provides the interface between dispatch consoles and the central controller in a typical trunking system

Answer 94

Switching equipment

Question 95

When setting up a trunking network, users with common missions or functions are assigned as

Answer 95

talkgroups

Question 96

Which statement is not a benefit of having a trunking network?

Answer 96

Unbalanced channel loads

Question 97

This differentiates the enterprise land mobile radio (ELMR) network from a regular trunking or conventional network

Answer 97

Centralized core controller

Question 98

Which Air Force instruction (AFI) requires communications squadrons to maintain installation notification and warning systems (INWS)?

Answer 98

AFI 10–2501, Air Force Emergency Management Program

Question 99

In the giant-voice system, this controls the system’s signal routing and power distribution

Answer 99

Control board

Question 100

Which is not a major component of the giant-voice system?

Answer 100

Decoder