1.
Which type of polarization is used to radiate a signal using a helical satellite antenna?
Correct Answer
C. Circular.
Explanation
A helical satellite antenna uses circular polarization to radiate a signal. Circular polarization is achieved by combining both horizontal and vertical polarizations in a rotating manner. This type of polarization is ideal for satellite communication as it helps to minimize signal degradation caused by reflections and interference. Circular polarization allows the antenna to receive and transmit signals from different angles, making it suitable for satellite communication where the orientation of the satellite may vary.
2.
This type of antenna is used to transmit and receive microwave signals.
Correct Answer
A. Horn.
Explanation
A horn antenna is commonly used for transmitting and receiving microwave signals. It is characterized by its flared shape, which allows for a wide radiation pattern and high gain. The design of a horn antenna helps to minimize interference and improve signal strength, making it suitable for various applications such as satellite communication, radar systems, and wireless networks. Unlike whip, helical, and log-periodic antennas, the horn antenna is specifically designed for microwave frequencies, making it the correct answer in this context.
3.
Where are aircraft antennas normally housed?
Correct Answer
A. Inside nonconductive radomes outside or flush with the fuselage.
Explanation
Aircraft antennas are typically housed inside nonconductive radomes, which are located either outside or flush with the fuselage. The purpose of the radome is to protect the antenna from external elements such as weather conditions, while also allowing the antenna to transmit and receive signals effectively. The use of nonconductive material ensures that the radome does not interfere with the antenna's performance.
4.
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?
Correct Answer
D. 5 and 30 degrees.
Explanation
In airborne antenna applications for frequencies in the upper portion of the high-frequency (HF) band, multi-hop, long-distance transmission should be used at vertical angles of 5 and 30 degrees. This is because at these angles, the radio waves can be effectively reflected off the ionosphere, allowing for long-distance communication. Vertical angles of 90 and 180 degrees would not be suitable as they would result in direct line-of-sight transmission, which is not ideal for long-distance communication. Similarly, angles of 60 and 90 degrees, as well as 30 and 60 degrees, would not provide the necessary reflection off the ionosphere for effective long-distance transmission.
5.
This is the best way to orient line-of-sight (LOS) antennas.
Correct Answer
D. In a straight path to the receiving station.
Explanation
The best way to orient line-of-sight (LOS) antennas is in a straight path to the receiving station. This ensures that there are no obstacles or obstructions between the transmitting and receiving stations, allowing for a clear and direct line of communication. Orienting the antennas toward the true north bearing or magnetic north bearing may not necessarily guarantee a straight path to the receiving station, and orienting them away from the receiving station would result in a loss of signal strength and quality. Therefore, the straight path to the receiving station is the most optimal orientation for LOS antennas.
6.
When siting a radio station, which type of foliage would have a more adverse effect on radio-wave propagation?
Correct Answer
A. Broadleaf trees.
Explanation
Broadleaf trees would have a more adverse effect on radio-wave propagation when siting a radio station. This is because broadleaf trees have denser foliage compared to evergreen trees, swamp grass, and sagebrush. The dense foliage of broadleaf trees can absorb and scatter radio waves, leading to a decrease in signal strength and coverage. On the other hand, evergreen trees, swamp grass, and sagebrush have less dense foliage, allowing radio waves to pass through with less obstruction.
7.
This has the greatest effect on an antenna’s radiation pattern.
Correct Answer
B. Earth.
Explanation
The Earth has the greatest effect on an antenna's radiation pattern because it acts as a reflective surface and can cause signal reflections and multipath interference. The Earth's terrain, buildings, and other obstructions can also block or attenuate the signal, leading to changes in the antenna's radiation pattern. Additionally, the Earth's atmosphere can introduce signal attenuation and scattering, further affecting the antenna's radiation pattern.
8.
This is one fundamental rule about camouflage.
Correct Answer
D. Straight lines are obvious.
Explanation
Straight lines are obvious in camouflage because they do not occur naturally in nature. In the wild, most objects and shapes have irregular and curved lines, making straight lines stand out and catch the eye. Straight lines can easily break the natural patterns and disrupt the camouflage effect, making the object or equipment more noticeable and easily detectable. Therefore, it is important to avoid using straight lines when applying camouflage techniques to blend in with the surroundings effectively.
9.
This is the most effective type of antennas in mountainous terrain that has a mountain between you and the distant end.
Correct Answer
D. Near-vertical incidence sky-wave.
Explanation
The near-vertical incidence sky-wave (NVIS) is the most effective type of antenna in mountainous terrain with a mountain between you and the distant end. NVIS antennas are designed to radiate signals at a high angle, allowing them to bounce off the ionosphere and back down to the earth's surface, making them ideal for communication over short to medium distances in mountainous areas. This type of antenna is specifically designed to overcome the challenges posed by mountains and provide reliable communication in such terrain.
10.
Which electronic warfare (EW) component responds to a tasking to search for, intercept, identify, and locate intentional and unintentional sources of radiated energy?
Correct Answer
C. Support.
Explanation
The correct answer is "Support." In electronic warfare (EW), the support component is responsible for tasks such as searching for, intercepting, identifying, and locating intentional and unintentional sources of radiated energy. This component provides crucial intelligence and information to assist in the overall EW operations.
11.
Electromagnetic (EM) deception, as it applies to electronic warfare (EW), is
Correct Answer
C. Conveying misleading information to an enemy through the deliberate radiation of EM energy.
Explanation
The correct answer is conveying misleading information to an enemy through the deliberate radiation of EM energy. Electromagnetic deception in electronic warfare involves intentionally emitting electromagnetic energy with the aim of deceiving the enemy by providing false or misleading information. This can be done through various techniques such as simulating false targets, creating fake communication signals, or manipulating radar signatures. By doing so, the enemy's perception and understanding of the battlefield can be distorted, leading to potentially wrong decisions and actions.
12.
In frequency-hopping (FH) operations, the interval at which each transmitter remains on a given frequency for a specific time is known as
Correct Answer
A. Dwell time.
Explanation
In frequency-hopping (FH) operations, the interval at which each transmitter remains on a given frequency for a specific time is known as dwell time. This refers to the duration for which the transmitter stays on a particular frequency before hopping to another frequency. It is an important parameter in FH systems as it determines the amount of time spent on each frequency and affects the overall performance and efficiency of the system.
13.
Which type of hopping-rate category changes frequencies approximately 100 times per second?
Correct Answer
B. Medium.
Explanation
The hopping-rate category that changes frequencies approximately 100 times per second is referred to as "Medium." This implies that the frequency changes at a moderate pace, neither too slow nor too fast. The other options, Slow and Fast, suggest different rates of frequency changes, while Conference is not related to the hopping-rate category.
14.
What does the term "ICOM" indicate?
Correct Answer
D. Integrated communications security.
Explanation
The term "ICOM" indicates Integrated Communications Security. This means that it refers to a system or technology that combines various methods and measures to protect and secure communications. It suggests that the communication system being referred to has integrated security features to ensure the confidentiality, integrity, and availability of the transmitted information.
15.
Which statement best identifies the requirements for two transceivers to establish HAVE QUICK (HQ) communications?
Correct Answer
D. They must have the same word of day (WOD) and time of day (TOD).
Explanation
The requirement for two transceivers to establish HAVE QUICK (HQ) communications is that they must have the same word of day (WOD) and time of day (TOD). This means that both transceivers need to be synchronized with the same WOD and TOD in order to effectively communicate with each other using HQ. The other statements, such as being the same model number or version of transceiver, or using the same encryption variables, do not specifically address the synchronization requirement needed for HQ communications.
16.
How long is each word-of-day (WOD) used with the HAVE QUICK II (HQII) communications multiple word-of-day (MWOD)?
Correct Answer
D. 24 hours.
Explanation
Each word-of-day (WOD) is used with the HAVE QUICK II (HQII) communications multiple word-of-day (MWOD) for a duration of 24 hours. This means that the WOD remains in use for a full day before it is manually changed.
17.
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?
Correct Answer
C. Link 11B.
Explanation
Link 11B is the correct answer because it is a secure, full-duplex, point-to-point digital data link that uses satellite, microwave, or terrestrial cable to transmit data. Link 11 and Link 16 are also tactical data links, but they use modulated waveforms instead of satellite, microwave, or terrestrial cable. Link 4 is not a secure, full-duplex, point-to-point digital data link.
18.
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?
Correct Answer
B. Time division.
Explanation
Time division is the correct answer because it eliminates the need for a net control station (NCS) in the joint tactical information distribution system (JTIDS) by providing node-less communications network architecture. In time division, the available time slots are divided among multiple users, allowing each user to have exclusive access to the channel during their allocated time slot. This eliminates the need for a central control station to manage and coordinate communication between users, making it a more efficient and decentralized method.
19.
The Air Force integrates with modified close air support aircraft with digitized battlefield information using this type of network.
Correct Answer
D. Situation awareness data link (SADL).
Explanation
The correct answer is Situation awareness data link (SADL). SADL is a type of network that allows the Air Force to integrate with modified close air support aircraft and provide them with digitized battlefield information. This network enables real-time sharing of situational awareness data, enhancing the effectiveness and coordination of air support operations.
20.
Which type of advanced waveform was designed to operate on manned, vehicular-based communication systems?
Correct Answer
B. Wideband networking.
Explanation
Wideband networking is the correct answer because it is a type of advanced waveform that was specifically designed to operate on manned, vehicular-based communication systems. It allows for high-speed data transmission and enables reliable communication between soldiers and vehicles in the field. The other options, soldier radio, mobile user objective system, and adaptive network wideband waveform, may be related to communication systems but are not specifically designed for manned, vehicular-based systems.