3d153v2 CDC Unit Review
100 Question Test CDC Unit Review, Volume 2
Questions and Answers
- 1.
Equipment used for generating, amplifying, and transmitting RF carrier is collectively called
- A.
A receiver.
- B.
An antenna.
- C.
A transmitter.
- D.
A transmission line.
Correct Answer
C. A transmitter.Explanation
The correct answer is a transmitter. In the context of generating, amplifying, and transmitting RF carrier, the equipment responsible for performing these functions is known as a transmitter. A transmitter is used to convert information or signals into a form suitable for transmission over the airwaves. It generates the RF carrier signal, amplifies it to the desired power level, and transmits it through an antenna.Rate this question:
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- 2.
What basic receiver function involves having the transmitted electromagnetic wave pass through the receive antenna in such a manner as to induce voltage in the antenna?
- A.
Reproduction
- B.
Reception
- C.
Detection
- D.
Selection
Correct Answer
B. ReceptionExplanation
Reception is the correct answer because it refers to the basic receiver function of having the transmitted electromagnetic wave pass through the receive antenna and induce voltage in the antenna. This process allows the receiver to capture the signal and convert it into a usable form for further processing or analysis.Rate this question:
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- 3.
The ability to reproduce the input signal accurately is the characteristics of the receiver's
- A.
Fidelity
- B.
Capacity
- C.
Sensetivity
- D.
Selectivity
Correct Answer
A. FidelityExplanation
Fidelity refers to the ability of a receiver to reproduce the input signal accurately. It is a measure of how well the receiver can maintain the original quality and integrity of the signal without any distortion or loss of information. A receiver with high fidelity will accurately reproduce the original signal, while a receiver with low fidelity may introduce noise, distortion, or other errors that degrade the signal quality. Therefore, fidelity is the correct characteristic that describes the ability to reproduce the input signal accurately.Rate this question:
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- 4.
A combination of a transmitter and receiver that is built as a single unit and sharing common tuned circuits is called a
- A.
Transmitter
- B.
Transceiver
- C.
Receiver
- D.
Coupler
Correct Answer
B. TransceiverExplanation
A transceiver is a combination of a transmitter and receiver that is built as a single unit and shares common tuned circuits. This allows for the transmission and reception of signals using the same device, making it more compact and convenient. Transceivers are commonly used in various communication systems, such as radios, wireless networks, and telecommunications equipment.Rate this question:
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- 5.
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
Correct Answer
D. Repair itselfExplanation
The transceiver's computerized components and micro-circuitry can perform specific equipment faults, internal equipment tests, and internal calibrations. However, it cannot repair itself. This means that if the transceiver experiences any damage or malfunction, it would require external intervention or manual repair rather than being able to fix the issue on its own.Rate this question:
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- 6.
A transmission line that consists of a center conductor placed inside a metal tube functioning as the outer tube is called a
- A.
Flexible coaxial cable
- B.
Rigid coaxial cable
- C.
Waveguide
- D.
Twin lead
Correct Answer
B. Rigid coaxial cableExplanation
A rigid coaxial cable is a transmission line that consists of a center conductor placed inside a metal tube functioning as the outer conductor. This design provides a high level of shielding and prevents interference from external sources. The rigid structure of the cable ensures that it maintains its shape and does not bend easily, making it suitable for applications where stability and durability are important.Rate this question:
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- 7.
Which selection best describes the term "cutoff frequency" when discussing the transmission line properties? XL = XL XC= XC
- A.
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
Correct Answer
B. The frequency where XC causes the signal to be shuntedExplanation
The cutoff frequency refers to the frequency at which the reactance of the capacitance (XC) in the transmission line becomes so low that it shunts or diverts the signal. At this frequency, the transmission line is no longer able to effectively pass the signal.Rate this question:
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- 8.
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
Correct Answer
D. 1.2 metersExplanation
The wavelength of a wave is inversely proportional to its frequency, according to the equation λ = c/f, where λ is the wavelength, c is the speed of light, and f is the frequency. As the frequency increases from 150 MHz to 250 MHz, the wavelength decreases. Therefore, the correct answer is 1.2 meters, which is the shortest wavelength among the given options.Rate this question:
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- 9.
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
Correct Answer
B. 8.33 wavelengthsExplanation
The electrical length of a waveguide or transmission line is typically measured in wavelengths. In this question, the frequency is changed from 150 MHz to 250 MHz. As the frequency increases, the wavelength decreases. Therefore, the electrical length would also decrease. The correct answer of "8.33 wavelengths" indicates that the electrical length is 8.33 times the wavelength at the given frequency.Rate this question:
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- 10.
A nonresonant transmission line is a line
- A.
Having reflected waves
- B.
Having no reflected waves
- C.
With maximum voltage across its open termination
- D.
With a maximum voltage across its shorted termination
Correct Answer
B. Having no reflected wavesExplanation
A nonresonant transmission line is a line that does not have any reflected waves. This means that all the energy transmitted through the line is absorbed and there are no waves bouncing back. This can be achieved by properly matching the impedance of the line with the load impedance. When there are no reflected waves, it indicates efficient power transfer and minimal signal loss along the transmission line.Rate this question:
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- 11.
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
Correct Answer
A. Current is at maximum and voltage at minimum at the terminationExplanation
When a transmission line is terminated in a short, it means that the impedance at the termination is very low. In this case, the current flowing through the line will be at its maximum because the low impedance allows for a larger current to flow. On the other hand, the voltage at the termination will be at its minimum because a low impedance causes a drop in voltage. Therefore, the correct answer is that the current is at maximum and the voltage is at minimum at the termination.Rate this question:
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- 12.
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
Correct Answer
A. AntennaExplanation
An antenna converts radio frequency (RF) energy's current oscillation into electric and magnetic fields of force. It is a device that radiates or receives electromagnetic waves. Antennas are used in communication systems to transmit or receive signals wirelessly. They convert the electrical current flowing through them into radio waves that can be transmitted through the air or other mediums.Rate this question:
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- 13.
The concept that alternation current (AC) changes in magnitude and reverses its direction during each cycle is
- A.
An unproved hypothesis
- B.
The definition of propogation
- C.
What makes radio transmission possible
- D.
What led to the discovery of direct current
Correct Answer
C. What makes radio transmission possibleExplanation
The concept that alternating current (AC) changes in magnitude and reverses its direction during each cycle is what makes radio transmission possible. AC allows for the creation and propagation of electromagnetic waves, which are used in radio transmission. The changing magnitude and direction of AC current allows for the modulation of these electromagnetic waves, enabling the transmission of information through radio waves.Rate this question:
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- 14.
If the electric field component travels in a plane perpendicular to the Earth's surface, the radio wave is
- A.
Magnetically polarized
- B.
Horizontally polarized
- C.
Circularly polarized
- D.
Vertically polarized
Correct Answer
D. Vertically polarizedExplanation
When the electric field component of a radio wave travels in a plane perpendicular to the Earth's surface, the radio wave is vertically polarized. This means that the electric field oscillates in a vertical direction, while the magnetic field oscillates in a horizontal direction. This type of polarization is commonly used in radio and television broadcasting, as it allows for efficient transmission and reception of signals.Rate this question:
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- 15.
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
Correct Answer
C. Transmit right hand and receive left hand circular polarizationsExplanation
Satellite terminals transmit right-hand circular polarization and receive left-hand circular polarization. Circular polarization is used in satellite communications because it helps to overcome the effects of signal fading and interference caused by the Earth's atmosphere and other obstructions. Transmitting and receiving circular polarization allows for better signal quality and reliability in satellite communication systems.Rate this question:
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- 16.
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
Correct Answer
B. Standing wave ratioExplanation
The standing wave ratio is used to determine whether an antenna is resonant at a particular frequency. This measurement compares the amplitude of the forward and reflected waves on the transmission line. A standing wave ratio of 1:1 indicates that the antenna is perfectly matched and resonant, while higher ratios indicate a mismatch and inefficiency in the antenna system.Rate this question:
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- 17.
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
Correct Answer
C. ReciprocityExplanation
Reciprocity refers to the ability of an antenna to both receive and transmit signals equally well. This means that the antenna's performance is the same regardless of whether it is used for receiving or transmitting. Reciprocity is an important characteristic of antennas as it allows for efficient and reliable communication. It ensures that the signals transmitted by the antenna are accurately received by the receiving device, and vice versa.Rate this question:
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- 18.
The standard used to measure the radiating effectiveness (gain) of an antenna system is the
- A.
Marconi antenna
- B.
Isotropic antenna
- C.
Hertz antenna
- D.
Whip antenna
Correct Answer
B. Isotropic antennaExplanation
The isotropic antenna is used as a standard to measure the radiating effectiveness or gain of an antenna system. An isotropic antenna is a theoretical antenna that radiates power uniformly in all directions. It is considered to be a reference point for measuring the gain of other antennas. The gain of an antenna is the ratio of the power radiated in a specific direction to the power radiated by an isotropic antenna. Therefore, the isotropic antenna serves as a benchmark for comparing and evaluating the performance of different antennas.Rate this question:
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- 19.
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
Correct Answer
A. Impedance matchingExplanation
The effectiveness of an entire transmitting and receiving system largely depends on impedance matching. Impedance matching ensures that the impedance of the transmitting device matches the impedance of the receiving device, allowing for maximum power transfer and minimizing signal loss. If there is a mismatch in impedance, it can lead to reflections and a decrease in signal quality, affecting the overall performance of the system. Therefore, impedance matching is crucial for optimizing the efficiency and effectiveness of the system.Rate this question:
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- 20.
Which antenna radiates radio energy in a circular pattern?
- A.
Omnidirectional
- B.
Unidirectional
- C.
Bidirectional
- D.
Directional
Correct Answer
A. OmnidirectionalExplanation
An omnidirectional antenna radiates radio energy in a circular pattern, meaning that it emits signals in all directions equally. This type of antenna is commonly used in situations where the signal needs to reach multiple locations or devices without the need for precise aiming or alignment. It is ideal for applications such as broadcast radio, Wi-Fi routers, and mobile communication towers, where a wide coverage area is desired.Rate this question:
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- 21.
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
Correct Answer
B. UnidirectionalExplanation
Unidirectional antennas are usually used on long-range, point-to-point circuits where concentrated radio energy is needed for circuitry reliability. These antennas have a focused radiation pattern that allows them to transmit and receive signals in a specific direction, providing a stronger and more reliable signal over long distances. Unlike omnidirectional antennas that radiate energy in all directions, unidirectional antennas concentrate the radio energy in a single direction, making them ideal for long-range communication. Bidirectional antennas can transmit and receive signals in two opposite directions, while circular antennas are designed for circular polarization and are not specifically used for long-range, point-to-point circuits.Rate this question:
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- 22.
Ungrounded lengths of wire specifically designed to be either a half-wavelength or more than full wavelength long is called a
- A.
Reflector
- B.
Hertz antenna
- C.
Marconi antenna
- D.
Vertical monopole
Correct Answer
B. Hertz antennaExplanation
A Hertz antenna is an ungrounded length of wire that is specifically designed to be either a half-wavelength or more than a full wavelength long. It is named after Heinrich Hertz, who first demonstrated the existence of electromagnetic waves. The Hertz antenna is used to radiate or receive radio waves and is commonly used in wireless communication systems.Rate this question:
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- 23.
A long-wire's takeoff angle depends on the antenna's
- A.
Length
- B.
Directivity
- C.
Front-to-back ratio
- D.
Standing wave ratio
Correct Answer
A. LengthExplanation
The takeoff angle of a long-wire antenna depends on its length. The longer the wire, the lower the takeoff angle will be. This is because longer wires have a lower radiation angle, meaning the signal is emitted closer to the ground. As a result, the signal can travel further distances without being obstructed by obstacles such as buildings or trees. Therefore, the length of the antenna plays a crucial role in determining the takeoff angle and the overall performance of the long-wire antenna.Rate this question:
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- 24.
All antennas used in satellite communications are designed to be
- A.
Circular directional
- B.
Omnidirectional
- C.
Bidirectional
- D.
Directional
Correct Answer
D. DirectionalExplanation
Directional antennas are designed to transmit and receive signals in a specific direction, allowing for focused and efficient communication. This is particularly important in satellite communications, where the signals need to be transmitted over long distances and with minimal interference. Directional antennas have a higher gain and can provide a stronger and more reliable signal compared to other types of antennas. They are commonly used in satellite communication systems to establish a direct line of sight between the satellite and the ground station, ensuring optimal signal strength and quality.Rate this question:
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- 25.
A common satellite antenna is the
- A.
Whip
- B.
Discone
- C.
Parabolic
- D.
Long-wire
Correct Answer
C. ParabolicExplanation
A parabolic satellite antenna is a common type of satellite antenna that uses a parabolic reflector to focus incoming radio waves onto a feed horn at its focal point. This design allows for high gain and directivity, making it ideal for long-range communication with satellites. The parabolic shape of the antenna helps to minimize signal loss and interference, resulting in a more efficient and reliable satellite communication.Rate this question:
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- 26.
A helical antenna radiates a signal with what type of polarization?
- A.
Horizontal
- B.
Vertical
- C.
Circular
- D.
Linear
Correct Answer
C. CircularExplanation
A helical antenna radiates a signal with circular polarization. This means that the electric field vector of the signal rotates in a circular motion as it propagates. Circular polarization allows the signal to maintain its polarization regardless of the orientation of the receiving antenna, making it more reliable in various applications.Rate this question:
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- 27.
Aircraft antennas are housed
- A.
Inside nonconductive radomes mounted outside or flush with the fuselage
- B.
Inside conductive radomes mounted outside or flush with the fuselage
- C.
Outside nonconductive radomes mounted outside the fuselage
- D.
Inside conductive radomes mounted flush with the fuselage
Correct Answer
A. Inside nonconductive radomes mounted outside or flush with the fuselageExplanation
Aircraft antennas are housed inside nonconductive radomes mounted outside or flush with the fuselage. Radomes are protective coverings that are made of nonconductive materials, such as fiberglass or composite materials. These radomes are mounted outside or flush with the fuselage to minimize interference with the antenna's signal reception and transmission. By housing the antennas inside these radomes, they are shielded from external factors such as weather conditions and aerodynamic effects, while still allowing them to effectively communicate with ground stations or other aircraft.Rate this question:
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- 28.
In airborne antenna applications for frequencies in the upper portion of the HF band, what vertical angles are used for multi-hop, long distance transmission?
- A.
90 and 180 degrees
- B.
60 and 90 degrees
- C.
30 and 60 degrees
- D.
5 and 30 degrees
Correct Answer
D. 5 and 30 degreesExplanation
In airborne antenna applications for frequencies in the upper portion of the HF band, the vertical angles used for multi-hop, long distance transmission are 5 and 30 degrees.Rate this question:
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- 29.
What determines an antenna's location and orientation on the aircraft?
- A.
Antennas always require a 360 degree radiating pattern
- B.
The type of aircraft propulsion and power system
- C.
Antennas are always mounted on top of the fuselage
- D.
Optimizing the antenna's radiating pattern for its application
Correct Answer
D. Optimizing the antenna's radiating pattern for its applicationExplanation
The correct answer is "optimizing the antenna's radiating pattern for its application." The location and orientation of an antenna on an aircraft are determined by the need to optimize its radiating pattern for its specific application. Different types of antennas may require different placement and orientation to ensure the best performance in terms of signal reception and transmission. Factors such as the aircraft's structure, interference from other systems, and the desired coverage area all play a role in determining the optimal location and orientation for an antenna.Rate this question:
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- 30.
Which type of airborne antenna can be designed into any part of an aerospace vehicle's surface, so that it does not upset its aerodynamic properties?
- A.
Fixed blade
- B.
Conformal
- C.
Probe tip
- D.
Whip
Correct Answer
B. ConformalExplanation
A conformal antenna is designed to seamlessly integrate into the surface of an aerospace vehicle without affecting its aerodynamic properties. Unlike other types of antennas, such as fixed blade or whip antennas, a conformal antenna can be shaped to match the contours of the vehicle, allowing for a streamlined appearance and reduced drag. This type of antenna is ideal for applications where maintaining the vehicle's aerodynamic performance is crucial, such as in aircraft or spacecraft design.Rate this question:
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- 31.
In selecting an antenna for a circuit, what is the first thing to look at?
- A.
Type of propogation
- B.
Selecting the antenna
- C.
Determine the distance
- D.
Finding the operating frequency
Correct Answer
A. Type of propogationExplanation
The first thing to look at when selecting an antenna for a circuit is the type of propagation. Different types of propagation, such as line-of-sight or non-line-of-sight, require different types of antennas for optimal performance. By considering the type of propagation, one can choose an antenna that is specifically designed to work well in that particular propagation environment.Rate this question:
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- 32.
Which object has the greatest effect on an antenna?
- A.
Sun
- B.
Earth
- C.
Operator
- D.
Ionosphere
Correct Answer
B. EarthExplanation
The Earth has the greatest effect on an antenna because it is the largest and closest object to the antenna. The Earth's gravitational pull and electromagnetic field can interfere with the antenna's signal reception and transmission. Additionally, the Earth's atmosphere and terrain can also affect the antenna's performance by causing signal reflections, absorption, or blockage.Rate this question:
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- 33.
Where is the most challenging location for a radio frequency (RF) transmission systems technician to establish and operate a radio station from?
- A.
Amazon jungle
- B.
North Pole
- C.
Sahara desert
- D.
Sierra Nevada mountains
Correct Answer
A. Amazon jungleExplanation
The Amazon jungle is the most challenging location for a radio frequency (RF) transmission systems technician to establish and operate a radio station from. This is because the dense vegetation and vast expanse of the jungle make it difficult for radio signals to penetrate and travel long distances. Additionally, the high humidity and constant rainfall in the region can interfere with the transmission and reception of radio waves. The presence of numerous obstacles such as trees and foliage further hinders the establishment of a reliable radio station in the Amazon jungle.Rate this question:
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- 34.
With a mountain between you and the distant end, which antenna is more effective?
- A.
Whip
- B.
Dipole
- C.
Discone
- D.
Near-vertical incidence skywave
Correct Answer
D. Near-vertical incidence skywaveExplanation
The near-vertical incidence skywave antenna is more effective when there is a mountain between you and the distant end. This is because the near-vertical incidence skywave antenna is designed to transmit and receive signals that are reflected off the ionosphere at very steep angles. This allows the signals to bypass obstacles like mountains and reach the distant end more effectively compared to other types of antennas such as whip, dipole, or discone antennas.Rate this question:
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- 35.
Direct waves are radio waves that travel
- A.
Long distances with few interruptions
- B.
From point to point along the earth's surface
- C.
Through the air in a straight line
- D.
No more than 20 miles to the receive antenna
Correct Answer
C. Through the air in a straight lineExplanation
Direct waves are radio waves that travel through the air in a straight line. This means that they do not bounce off or get obstructed by any objects or obstacles in their path. As a result, they can travel long distances with few interruptions from point to point along the earth's surface. However, their range is limited to no more than 20 miles to the receive antenna.Rate this question:
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- 36.
Radio waves that travel near the earth's surface are called
- A.
Earth waves
- B.
Global waves
- C.
Ground waves
- D.
Terrestrial waves
Correct Answer
C. Ground wavesExplanation
Ground waves are radio waves that travel near the Earth's surface. These waves are able to follow the curvature of the Earth and can travel over long distances. Ground waves are commonly used for broadcasting radio signals and are able to penetrate buildings and other obstacles. They are different from sky waves, which are radio waves that are reflected off the ionosphere and can travel much farther distances. Therefore, ground waves are the correct term for radio waves that travel near the Earth's surface.Rate this question:
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- 37.
Sky wave transmission is used for which type of communications?
- A.
Long distance
- B.
Subterrestrial
- C.
Atmospheric
- D.
Line of sight
Correct Answer
A. Long distanceExplanation
Sky wave transmission is used for long distance in the range of 3-300 MHz (pg. 2-3)Rate this question:
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- 38.
The path that undergoes 180 degrees phase shift is a
- A.
Ground-reflected path
- B.
Surface path
- C.
Direct path
- D.
Sky path
Correct Answer
A. Ground-reflected pathExplanation
A ground-reflected path undergoes a 180 degrees phase shift because when a signal reaches the ground, it reflects back towards the receiver. This reflection causes the signal to experience a phase shift of 180 degrees compared to the direct path. This phenomenon is commonly observed in radio wave propagation, where signals can bounce off the ground and create a ground-reflected path.Rate this question:
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- 39.
Which gives sky wave propagation its ability to communicate beyond the optical line-of-sight (LOS)?
- A.
Refraction
- B.
Refletion
- C.
Earth's conductivity
- D.
Atmospheric charge
Correct Answer
A. RefractionExplanation
Refraction is the correct answer because it is the bending of radio waves as they pass through different layers of the atmosphere. This bending allows the waves to follow the curvature of the Earth, enabling communication beyond the optical line-of-sight. Refraction is caused by the variation in the density of the atmosphere, which results in changes in the speed of the radio waves. This phenomenon is crucial for long-distance communication, as it allows signals to be transmitted over the horizon and reach receivers that are out of the direct line-of-sight.Rate this question:
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- 40.
Frequencies higher than the critical frequency are
- A.
Returned to earth
- B.
Passed into space
- C.
The most desirable
- D.
Refracted by the F2 layer
Correct Answer
B. Passed into spaceExplanation
Frequencies higher than the critical frequency are passed into space. This is because the critical frequency is the maximum frequency that can be refracted back to Earth by the F2 layer of the atmosphere. Any frequencies higher than the critical frequency are not able to be refracted and therefore pass through the F2 layer and continue into space.Rate this question:
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- 41.
In high frequency (HF) communications, the lowest frequency that arrives at the distant receiver on 90 percent of the undisturbed days of the month is called the
- A.
Maximum usable frequency (MUF)
- B.
Lowest usable frequency (LUF)
- C.
Operating frequency
- D.
Critical frequency
Correct Answer
B. Lowest usable frequency (LUF)Explanation
The lowest usable frequency (LUF) refers to the lowest frequency that can be reliably received at a distant receiver on most undisturbed days of the month in high frequency (HF) communications. It represents the minimum frequency that can be used for effective communication without significant interference or signal degradation. The LUF is an important parameter to consider when determining the appropriate frequency for HF communication to ensure reliable transmission and reception.Rate this question:
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- 42.
The abbreviation FOT is derived from the term
- A.
Outbound traffic frequency
- B.
Optimom tropospheric frequency
- C.
Frequency of optimum transmission
- D.
Frequency of outbound transmission
Correct Answer
C. Frequency of optimum transmissionExplanation
The abbreviation FOT stands for "frequency of optimum transmission". This means that FOT refers to the frequency at which transmission is optimal or most efficient. It implies that there is a specific frequency at which data or signals can be transmitted with the least amount of interference or loss.Rate this question:
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- 43.
Magneton splitting creates two waves called
- A.
Direct and indirect
- B.
Ordinary and abnormal
- C.
In-phase and out-of-phase
- D.
Ordinary and extraordinary
Correct Answer
D. Ordinary and extraordinaryExplanation
Magneton splitting refers to the phenomenon where the energy levels of a magnetic material split into two distinct levels when placed in a magnetic field. This splitting results in the creation of two waves, known as ordinary and extraordinary waves. The ordinary wave propagates with the same velocity in all directions, while the extraordinary wave propagates with different velocities depending on the direction. Therefore, the answer "ordinary and extraordinary" accurately describes the two waves created by magneton splitting.Rate this question:
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- 44.
What occurs when a transmitted signal travels over two or more separate paths during transmission?
- A.
Skip effects
- B.
Modulation
- C.
Multipathing
- D.
Magneton splitting
Correct Answer
C. MultipathingExplanation
When a transmitted signal travels over two or more separate paths during transmission, it experiences multipathing. This phenomenon happens when the signal reflects, refracts, or diffracts off objects in its path, resulting in multiple copies of the signal reaching the receiver at slightly different times and angles. Multipathing can cause interference, signal fading, and distortion, affecting the quality and reliability of the transmitted signal.Rate this question:
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- 45.
What is the recombination process dependent upon?
- A.
Season
- B.
Time of day
- C.
Regular variation
- D.
Irregular variations
Correct Answer
B. Time of dayExplanation
The recombination process is dependent upon the time of day. This suggests that the process of recombination, which involves the rearrangement of genetic material, is influenced by the specific time of day. It implies that the timing of certain biological processes, such as DNA repair and replication, may play a crucial role in recombination. The answer choice "time of day" aligns with this understanding, indicating that the recombination process is influenced by the specific time within a day.Rate this question:
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- 46.
Which layer of the ionosphere is most important to high frequency (HF) communications?
- A.
D
- B.
E
- C.
F
- D.
Topside
Correct Answer
C. FExplanation
The F layer of the ionosphere is the most important for high frequency (HF) communications. This layer is located at an altitude of approximately 150-400 km above the Earth's surface. It is significant for HF communications because it is capable of reflecting HF radio waves back to the Earth's surface, thus allowing long-distance communication over large areas. The F layer is further divided into two sub-layers, F1 and F2, with the F2 layer being the most important for HF communications due to its higher electron density and stronger reflection capabilities.Rate this question:
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- 47.
During what season do we have the wider range of critical frequencies and less absorption of all frequencies?
- A.
Fall
- B.
Winter
- C.
Spring
- D.
Summer
Correct Answer
B. WinterExplanation
During winter, the air is colder and denser, which allows sound waves to travel further and with less absorption. This results in a wider range of critical frequencies being heard compared to other seasons. In contrast, during summer, the air is warmer and less dense, causing sound waves to be absorbed more quickly and limiting the range of critical frequencies that can be heard. Therefore, winter is the season with the wider range of critical frequencies and less absorption of all frequencies.Rate this question:
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- 48.
Sunspots are disturbances
- A.
In the sun's atmosphere
- B.
On the sun's surface
- C.
In the ionosphere
- D.
Beneath the sun's surface
Correct Answer
B. On the sun's surfaceExplanation
Sunspots are disturbances that occur on the sun's surface. These are dark spots that appear to be cooler than the surrounding areas, caused by intense magnetic activity. Sunspots are often associated with solar flares and other solar phenomena. They can vary in size and shape and are important for studying the sun's magnetic field and its effects on space weather. Therefore, the correct answer is "on the sun's surface."Rate this question:
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- 49.
For communications purposes, the usable frequency spectrum ranges from
- A.
3 hertz (Hz) to 300 gigahertz (GHz+)
- B.
300 Hz to 300 GHz
- C.
3000 Hz to 3000 GHz
- D.
30 megahertz (MHz) to 300 MHz
Correct Answer
A. 3 hertz (Hz) to 300 gigahertz (GHz+)Explanation
The usable frequency spectrum for communication purposes ranges from 3 hertz (Hz) to 300 gigahertz (GHz+). This means that frequencies within this range can be effectively used for transmitting and receiving signals for communication. Frequencies below 3 Hz or above 300 GHz may not be suitable or practical for communication purposes.Rate this question:
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- 50.
What U.S. government agency divides the radio frequency (RF) spectrum into different bands?
- A.
Federal Aviation Agency
- B.
American National Standard Institute
- C.
Federal Communications Commission
- D.
Institute of Electrical & Electronics Engineers, Inc.
Correct Answer
C. Federal Communications CommissionExplanation
The Federal Communications Commission (FCC) is the U.S. government agency responsible for dividing the radio frequency (RF) spectrum into different bands. The FCC regulates and licenses the use of the RF spectrum to ensure efficient and interference-free communication. They allocate specific frequency bands to different services such as television, radio, cellular communication, and wireless internet. This helps to prevent overlap and interference between different users and allows for the smooth operation of various wireless devices and services.Rate this question:
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Current Version
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Mar 21, 2023Quiz Edited by
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May 25, 2011Quiz Created by
Ashley_baker
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