Communications Reviewer 1 Multiple Choice
Questions and Answers
- 1.
It is the scientist who is engaged in the study in the field of acoustics
- A.
Acoustician
- B.
Acoustist
- C.
Acoustics Engineer
- D.
Acoustics Scientist
Correct Answer
A. AcousticianExplanation
An acoustician is a scientist who specializes in the study of acoustics, which is the branch of physics that deals with the properties of sound and how it interacts with its environment. Acousticians conduct research, design and analyze acoustic systems, and provide solutions for various applications such as noise control, audio engineering, and architectural acoustics. Therefore, the correct answer is Acoustician.Rate this question:
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- 2.
Who coined the term "cyberspace?"
- A.
William Gibson
- B.
Antonio Meucci
- C.
Mel Gibson
- D.
Antonio Banderas
Correct Answer
A. William GibsonExplanation
William Gibson is the correct answer because he is the science fiction author who coined the term "cyberspace" in his 1984 novel "Neuromancer." Gibson's novel popularized the concept of a virtual reality space accessed through computer networks, and his use of the term has since become widely adopted in discussions about the internet and digital technology.Rate this question:
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- 3.
For educational purposes, who is the person who first discovered/invented the telephone?
- A.
Antonio Meucci
- B.
William Gibson
- C.
Antonio Banderas
- D.
Mel Gibson
Correct Answer
A. Antonio MeucciExplanation
Antonio Meucci is credited with the invention of the telephone. He was an Italian inventor and is known for developing a working prototype of the telephone in the 1840s. Although Alexander Graham Bell is often associated with the invention of the telephone, Meucci's contributions were acknowledged by the US Congress in 2002, recognizing him as the true inventor of the telephone.Rate this question:
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- 4.
What is the frequency of the middle C?
- A.
262 Hz
- B.
363 Hz
- C.
633 Hz
- D.
622 Hz
Correct Answer
A. 262 HzExplanation
Middle C is a specific musical note that is commonly used as a reference point in music. It is typically defined as having a frequency of 262 Hz. This means that the sound wave of middle C repeats 262 times in one second. The other options provided (363 Hz, 633 Hz, and 622 Hz) are not the correct frequencies for middle C.Rate this question:
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- 5.
What is the frequency of the upper side/ above middle C?
- A.
524 Hz
- B.
534 Hz
- C.
544 Hz
- D.
554 Hz
Correct Answer
A. 524 HzExplanation
The frequency of the upper side/above middle C is 524 Hz. This means that when playing a note above middle C on a musical instrument, the sound wave produced will vibrate at a frequency of 524 times per second.Rate this question:
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- 6.
It is the loudness level (in pHON) of a watch ticking.
- A.
20 PHON
- B.
30 PHON
- C.
40 PHON
- D.
50 PHON
Correct Answer
A. 20 pHONExplanation
The correct answer is 20 PHON. PHON is a unit used to measure the loudness level of a sound. A watch ticking is a relatively quiet sound, so it would have a low loudness level. Therefore, 20 PHON is the most appropriate option as it represents a low level of loudness.Rate this question:
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- 7.
What is the maximum limit time of exposure on sound levels between 100 dB and 110 dB?
- A.
20 minutes
- B.
22 minutes
- C.
24 minutes
- D.
26 minutes
Correct Answer
A. 20 minutesExplanation
Exposure to sound levels between 100 dB and 110 dB should not exceed 20 minutes. This is because prolonged exposure to high sound levels can cause damage to the ears and lead to hearing loss. The 20-minute limit helps to protect individuals from the potential harmful effects of loud noise.Rate this question:
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- 8.
What is the colloquial name for the term "Thin Ethernet"?
- A.
Cheapernet
- B.
Cheapnet
- C.
Choppednet
- D.
Thinet
Correct Answer
A. CheapernetExplanation
"Cheapernet" is the colloquial name for the term "Thin Ethernet". This term refers to a type of Ethernet cabling that is less expensive and thinner than the standard Ethernet cabling. It was commonly used in the early days of networking when cost was a significant factor. The name "Cheapernet" reflects the cost-effectiveness of this type of cabling compared to other options.Rate this question:
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- 9.
Local Multipoint Distribution Service (LMDS) operates at what frequency range?
- A.
27 - 31 GHz
- B.
31 - 35 GHz
- C.
35 - 39 GHz
- D.
39 - 41 GHz
Correct Answer
A. 27 - 31 GHzExplanation
LMDS operates at a frequency range of 27 - 31 GHz. This frequency range is commonly used for wireless broadband communication. LMDS is a wireless communication technology that provides high-speed data transmission over short distances. It is often used in urban areas where the deployment of wired infrastructure is difficult or expensive. The 27 - 31 GHz frequency range allows for high data transfer rates and low latency, making it suitable for applications that require fast and reliable internet connectivity.Rate this question:
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- 10.
A video signal that has no sync signal is what you called
- A.
Non-composite Video Signal
- B.
Composite Video Signal
- C.
Non Video Signal
- D.
None of the choices
Correct Answer
A. Non-composite Video SignalExplanation
A video signal that has no sync signal is referred to as a non-composite video signal. This means that the video signal does not include the synchronization information necessary for proper display. In a composite video signal, the sync signal is combined with the video signal to ensure correct timing and synchronization between the display device and the video source. Therefore, a video signal without a sync signal would be considered a non-composite video signal.Rate this question:
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- 11.
It is the gas that is used in jet engines.
- A.
Hydrazine
- B.
Dryhazine
- C.
Hitrazine
- D.
Monozine
Correct Answer
A. HydrazineExplanation
Hydrazine is the correct answer because it is a highly reactive and toxic chemical compound that is commonly used as a propellant in rocket and jet engines. It is known for its high energy content and ability to generate large amounts of thrust, making it an ideal fuel for powering aircraft engines. Additionally, hydrazine has a low freezing point and is stable at high temperatures, further enhancing its suitability for use in jet engines.Rate this question:
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- 12.
A satellite is put into final geosynchronous orbit from its transfer orbit by firing the __________.
- A.
Apogee kick motor
- B.
Perigee kick motor
- C.
Apogee punch motor
- D.
Perigee punch motor
Correct Answer
A. Apogee kick motorExplanation
The correct answer is apogee kick motor. A satellite is put into its final geosynchronous orbit from its transfer orbit by firing the apogee kick motor. The apogee kick motor is responsible for providing the necessary thrust to increase the satellite's apogee (the point in its orbit farthest from the Earth) and adjust its orbit to achieve the desired geosynchronous orbit. This motor is typically used to circularize the satellite's orbit and ensure it stays in a fixed position relative to the Earth's surface.Rate this question:
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- 13.
A terrestrial communications channel linking an earth station to a local switching network or population center
- A.
Backhaul
- B.
Fronthaul
- C.
SideHaul
- D.
TopHaul
Correct Answer
A. BackhaulExplanation
Backhaul refers to a terrestrial communications channel that connects an earth station to a local switching network or population center. It is the transmission of data from a remote site back to a central site or data center. This term is commonly used in the telecommunications industry to describe the network infrastructure that carries data traffic between cell towers and the core network. It is an essential component in providing reliable and efficient communication services to end-users.Rate this question:
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- 14.
Polytetrafluoroethylene is also known as
- A.
Teflon
- B.
Micah
- C.
Glass
- D.
Tissue
Correct Answer
A. TeflonExplanation
Polytetrafluoroethylene, commonly known as Teflon, is a synthetic fluoropolymer of tetrafluoroethylene. It is well-known for its nonstick properties and is widely used as a coating for cookware and in various industrial applications. Teflon is highly resistant to heat, chemicals, and electrical conductivity, making it a versatile material. Micah, glass, and tissue are unrelated to polytetrafluoroethylene and do not refer to its alternate names or characteristics.Rate this question:
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- 15.
For SSB transmitter, the average power is typically __________ of the peak envelope power, with a typical human speech
- A.
1/4 to 1/3
- B.
1/5 to 1/4
- C.
1/3 to 1/2
- D.
1/8 to 1/5
Correct Answer
A. 1/4 to 1/3Explanation
For SSB (Single Sideband) transmitters, the average power is typically 1/4 to 1/3 of the peak envelope power. This means that the power of the transmitted signal, on average, is about one-fourth to one-third of the maximum power that the transmitter is capable of producing. This is because SSB modulation techniques allow for the elimination of one of the sidebands and the carrier signal, resulting in a more efficient use of power compared to other modulation techniques. Additionally, the typical human speech signal has a dynamic range that is well-suited for this power range.Rate this question:
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- 16.
It is often called text messaging, is a means of sending short messages to and from mobile phones.
- A.
The Short Message Service (SMS)
- B.
The Long Message Service (LMS)
- C.
The Multimedia Message Service (MMS)
- D.
None of the choices
Correct Answer
A. The Short Message Service (SMS)Explanation
SMS, or Short Message Service, is a means of sending short messages to and from mobile phones. It is often referred to as text messaging. This service allows users to send and receive brief messages, typically limited to 160 characters. SMS has become a popular form of communication due to its convenience and widespread availability on mobile devices. It is not to be confused with LMS (Long Message Service) or MMS (Multimedia Message Service), which offer different capabilities for sending longer messages or messages with multimedia content.Rate this question:
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- 17.
North American type of sound files as a substitute for MP3
- A.
AC-3 Dolby
- B.
AC-4 Dolby
- C.
AC-5 Dolby
- D.
AC-2 Dolby
Correct Answer
A. AC-3 DolbyExplanation
AC-3 Dolby is the correct answer because it is a sound file format commonly used in North America as a substitute for MP3. AC-4, AC-5, and AC-2 Dolby are not commonly used sound file formats and therefore not suitable substitutes for MP3.Rate this question:
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- 18.
A table showing the pre-calculated position of satellite at any given time
- A.
Ephemeris
- B.
Edomeris
- C.
Both of the choices
- D.
None of the choices
Correct Answer
A. EpHemerisExplanation
Ephemeris refers to a table or data that provides the pre-calculated positions of a satellite at any given time. It is a valuable resource for tracking and predicting the location of satellites. The term "Edomeris" is not a recognized term in this context, and therefore, it is not a correct answer. The correct answer is "Ephemeris."Rate this question:
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- 19.
How many Horizontal scanning lines are there in HDTV?
- A.
1125
- B.
562.5
- C.
1200
- D.
281.25
Correct Answer
A. 1125Explanation
HDTV has 1125 horizontal scanning lines. This means that the screen is divided into 1125 horizontal rows, each containing pixels that make up the image. The more scanning lines a display has, the higher the resolution and clarity of the image. Therefore, 1125 is the correct answer for the number of horizontal scanning lines in HDTV.Rate this question:
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- 20.
How long that a GPS satellite completes its orbit?
- A.
12 hrs
- B.
6 hrs
- C.
24 hrs
- D.
18 hrs
Correct Answer
A. 12 hrsExplanation
A GPS satellite completes its orbit in 12 hours. This is because the GPS satellite system is designed to have satellites in six different orbital planes, with each plane containing four satellites. The satellites are evenly spaced in their respective planes to ensure continuous coverage. By having satellites in multiple planes, the system can provide global coverage. Each satellite orbits the Earth twice a day, taking approximately 12 hours to complete one orbit. This allows for accurate positioning and navigation data to be transmitted to GPS receivers on the ground.Rate this question:
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- 21.
What is the other term for parity check?
- A.
Vertical Redundancy Check
- B.
Horizontal Redundancy Check
- C.
Vertical Check
- D.
Horizontal Check
Correct Answer
A. Vertical Redundancy CheckExplanation
The other term for parity check is Vertical Redundancy Check. This method is used to detect errors in data transmission by adding an extra bit to each data unit. This extra bit is used to ensure that the total number of 1s in the data unit, including the extra bit, is either even or odd. If the count of 1s does not match the expected parity, an error is detected. Therefore, the term "Vertical Redundancy Check" is synonymous with parity check.Rate this question:
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- 22.
What is the other name for single button microphone?
- A.
Carbon Button
- B.
Mono Phone
- C.
Buttonphone
- D.
Micro Button
Correct Answer
A. Carbon ButtonExplanation
A single button microphone is commonly known as a Carbon Button microphone. This type of microphone uses a carbon button as the main component to convert sound waves into electrical signals. The carbon button acts as a variable resistor, changing its resistance as it vibrates in response to sound waves. This variation in resistance is then converted into an electrical signal that can be amplified and transmitted.Rate this question:
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- 23.
Instrument that is used in measuring the virtual height of ionosphere
- A.
Ionosonde
- B.
Isocone
- C.
Ionicode
- D.
Virtual Ion
Correct Answer
A. IonosondeExplanation
An ionosonde is an instrument used to measure the virtual height of the ionosphere. It works by transmitting a radio wave signal towards the ionosphere and then receiving the reflected signal. By analyzing the time it takes for the signal to travel and return, the ionosonde can determine the virtual height of the ionosphere at different frequencies. This information is crucial for studying and understanding the behavior of the ionosphere, which is important for various applications like radio communication and navigation systems.Rate this question:
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- 24.
An instrument used to measure relative height, layers in the ionosphere regarding wave propagation?
- A.
Ionosonde
- B.
Isocone
- C.
Ionicode
- D.
Virtual Ion
Correct Answer
A. IonosondeExplanation
An ionosonde is an instrument used to measure the relative height and layers in the ionosphere in terms of wave propagation. It is specifically designed to study the ionosphere and its characteristics, such as electron density, frequency, and amplitude of radio waves. By sending out radio waves and analyzing the reflected signals, an ionosonde can provide valuable information about the ionosphere's structure and behavior. The other options, Isocone, Ionicode, and Virtual Ion, are not instruments used for this purpose and are not related to measuring the ionosphere.Rate this question:
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- 25.
In a trapezoid modulation, 100% modulation will result to what waveform?
- A.
Triangular waveform
- B.
Square waveform
- C.
Sine waveform
- D.
Sawtooth waveform
Correct Answer
A. Triangular waveformExplanation
In a trapezoid modulation, the 100% modulation will result in a triangular waveform. This is because trapezoid modulation involves varying the amplitude of a carrier signal by a modulating signal. When the modulation is at 100%, the amplitude of the carrier signal is fully varied, resulting in a waveform that resembles a triangle with straight sides and a pointed peak.Rate this question:
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- 26.
It is the type of navigation that is based in Newton's Law of motion
- A.
Inertial Navigation System
- B.
Newton's Navigation System
- C.
Reactional Navigation System
- D.
Interactional Navigation System
Correct Answer
A. Inertial Navigation SystemExplanation
The correct answer is Inertial Navigation System. Inertial navigation is a type of navigation system that relies on Newton's laws of motion. It uses accelerometers and gyroscopes to measure changes in velocity and direction, allowing for accurate tracking of an object's position and movement. This system is commonly used in aircraft, submarines, and spacecraft, where GPS signals may be unavailable or unreliable.Rate this question:
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- 27.
What type of navigation system that currently used in aircraft, submarines, spacecraft and guided missiles.
- A.
Inertial Navigation System
- B.
Guided Missile System
- C.
Warcraft Navigation System
- D.
None of the choices
Correct Answer
A. Inertial Navigation SystemExplanation
The correct answer is Inertial Navigation System. This type of navigation system is currently used in aircraft, submarines, spacecraft, and guided missiles. It uses a combination of accelerometers and gyroscopes to measure the vehicle's acceleration and rotation, allowing it to calculate its position and orientation. This system is independent of external references such as GPS and is therefore highly reliable and accurate.Rate this question:
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- 28.
What is the successor of Bluetooth?
- A.
Lisbon
- B.
Infrared
- C.
Seattle
- D.
Redtooth
Correct Answer
A. Lisbon -
- 29.
What is the successor of Bluetooth after Lisbon?
- A.
Seattle
- B.
Infrared
- C.
Lisbon
- D.
Redtooth
Correct Answer
A. SeattleExplanation
The successor of Bluetooth after Lisbon is Seattle. This implies that Seattle is the next technology or version that is expected to replace or succeed Bluetooth after Lisbon.Rate this question:
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- 30.
Carrier freq is also known as
- A.
Rest freq
- B.
Courier freq
- C.
Horse freq
- D.
Navigational freq
Correct Answer
A. Rest freqExplanation
Carrier frequency refers to the frequency of the electromagnetic wave that is used to carry the information signal in a communication system. It is also known as the "rest frequency" because it represents the base frequency at which the carrier wave operates. The other options, such as "courier freq," "horse freq," and "navigational freq," do not accurately describe the concept of carrier frequency and are therefore incorrect.Rate this question:
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- 31.
Who developed the superheterodyne receiver
- A.
Edwin Armstrong
- B.
Thomas Edison
- C.
Albert Einstein
- D.
Heinrich Hertz
Correct Answer
A. Edwin ArmstrongExplanation
Edwin Armstrong developed the superheterodyne receiver. The superheterodyne receiver is a type of radio receiver that uses frequency mixing to convert the incoming radio frequency signal to a fixed intermediate frequency. This intermediate frequency is easier to amplify and process, resulting in better signal quality and selectivity. Armstrong's invention revolutionized radio technology and became the standard for radio receivers, leading to significant advancements in communication systems.Rate this question:
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- 32.
When the angle of incidence is equal to the angle of refraction, the light in the fiber optics is in what direction
- A.
Along the normal path
- B.
In a multiple path
- C.
Along reflected path
- D.
Along refracted path
Correct Answer
A. Along the normal pathExplanation
When the angle of incidence is equal to the angle of refraction, it means that the light is entering the fiber optics at a specific angle and bending at the same angle as it passes through the interface between two mediums. This phenomenon is known as total internal reflection. In this case, the light continues to travel along the normal path, following the direction perpendicular to the interface.Rate this question:
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- 33.
What refers to the sampling of analog signal using a sample and hold circuit, such that the sample has the same amplitude for its whole duration
- A.
Flat top sample
- B.
Flat down sample
- C.
Top sample
- D.
Down sample
Correct Answer
A. Flat top sampleExplanation
A flat top sample refers to the sampling of an analog signal using a sample and hold circuit in such a way that the sampled signal maintains a constant amplitude throughout its entire duration. This means that the sampled signal does not experience any variations or fluctuations in its amplitude during the sampling process.Rate this question:
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- 34.
What is the antenna height of a CB (Citizen Band) radio?
- A.
60 ft above the ground and 20 above the building
- B.
300 ft above the ground and 60 above the building
- C.
100 ft above the ground and 50 above the building
- D.
80 ft above the ground and 30 above the building
Correct Answer
A. 60 ft above the ground and 20 above the buildingExplanation
The antenna height of a CB (Citizen Band) radio is 60 ft above the ground and 20 ft above the building.Rate this question:
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- 35.
What is the nearest star in the solar system
- A.
Proxima centauri
- B.
Neutron star
- C.
White dwarf
- D.
Orion
Correct Answer
A. Proxima centauriExplanation
Proxima Centauri is the nearest star to our solar system. It is a red dwarf star located about 4.24 light-years away from Earth in the Alpha Centauri star system. Proxima Centauri is closer to us than any other known star, making it the correct answer to the question. Neutron stars and white dwarfs are different types of stars that are not the closest to our solar system. Orion, on the other hand, is not a star but a constellation in the night sky.Rate this question:
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- 36.
A rocket has two satellites, the smaller will continue to propel in the space after the bigger satellite has been launched. What do you call this bigger satellite?
- A.
Initial payload
- B.
Final payload
- C.
Giant payload
- D.
Golliath payload
Correct Answer
A. Initial payloadExplanation
The term "initial payload" refers to the bigger satellite that is launched first from the rocket. This satellite is responsible for carrying and deploying the smaller satellite into space. Once the smaller satellite is launched, the bigger satellite's mission is complete, and it will continue to propel in space while the smaller satellite carries out its intended tasks.Rate this question:
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- 37.
What antenna is used in radar?
- A.
Horn with parabolic reflector which rotates 360 degree
- B.
Horn with parabolic reflector which rotates 180 degree
- C.
Horn with parabolic reflector which rotates 270 degree
- D.
Horn with parabolic reflector which rotates 120 degree
Correct Answer
A. Horn with parabolic reflector which rotates 360 degreeExplanation
The correct answer is "horn with parabolic reflector which rotates 360 degree". This type of antenna is commonly used in radar systems because it provides a wide coverage area and allows for scanning the entire surrounding space. The rotation of the antenna helps in detecting and tracking objects from different directions, ensuring comprehensive radar coverage. The horn shape of the antenna helps in focusing and directing the radar signals, while the parabolic reflector enhances the antenna's gain and directivity.Rate this question:
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- 38.
What is the distance which needs a repeater in the microwave communication?
- A.
40 km
- B.
60 km
- C.
80 km
- D.
20 km
Correct Answer
A. 40 kmExplanation
Microwave communication involves transmitting signals using microwave frequencies. These signals can travel long distances without the need for repeaters. However, as the distance increases, the signal strength weakens. A repeater is used to amplify and regenerate the signal, ensuring it reaches its destination without significant degradation. In this case, the correct answer is 40 km, indicating that after this distance, a repeater is typically required to maintain the signal quality in microwave communication.Rate this question:
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- 39.
Terrestrial microwave antennas has an input and output impedance of ________ ohms.
- A.
50
- B.
60
- C.
70
- D.
40
Correct Answer
A. 50Explanation
Terrestrial microwave antennas typically have an input and output impedance of 50 ohms. This impedance value is commonly used in microwave communication systems, as it provides a balanced and efficient transfer of power between the antenna and the transmission line. It ensures minimal signal loss and maximizes the signal strength, making it the standard impedance for many microwave antenna designs.Rate this question:
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- 40.
Radio format that uses Mpeg 4 video compression
- A.
Divx
- B.
Divv
- C.
Divy
- D.
Divz
Correct Answer
A. DivxExplanation
Divx is the correct answer because it is a popular video codec that uses Mpeg 4 video compression. It allows for high-quality video playback while maintaining a relatively small file size. Divx is widely used for compressing and distributing videos over the internet, making it a suitable choice for radio formats that incorporate video content. Divv, Divy, and Divz are not valid options as they do not correspond to any known video compression formats.Rate this question:
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- 41.
What is the typical value of velocity factor of an open wire transmission line?
- A.
0.9
- B.
1.0
- C.
0.8
- D.
1.1
Correct Answer
A. 0.9Explanation
The typical value of the velocity factor of an open wire transmission line is 0.9. Velocity factor is a measure of how fast a signal travels through a transmission line compared to the speed of light in a vacuum. A value of 0.9 means that the signal travels at 90% of the speed of light in a vacuum.Rate this question:
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- 42.
Type of resistor use to reduced flicker noise voltage (0.02 to 0.2 mV)
- A.
Metal film
- B.
Carbon film
- C.
Mono film
- D.
Cinema film
Correct Answer
A. Metal filmExplanation
Metal film resistors are commonly used to reduce flicker noise voltage in electronic circuits. Flicker noise, also known as 1/f noise, is a type of noise that increases at lower frequencies. Metal film resistors have a low noise level and are known for their stability and accuracy. They provide a consistent and reliable performance, making them suitable for applications where low noise is essential. Carbon film resistors, on the other hand, tend to have higher noise levels and are not as effective in reducing flicker noise voltage. Mono film and cinema film are not relevant to the reduction of flicker noise voltage.Rate this question:
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- 43.
In 2002, a standard for (BWA) Broadband Wireless Access was introduced and in the IEEE standard it is more commonly known as 802.16. This also refers to
- A.
WiMax
- B.
WiBro
- C.
Zigbee
- D.
None of the choices
Correct Answer
A. WiMaxExplanation
The correct answer is WiMax. In 2002, a standard for Broadband Wireless Access (BWA) was introduced, which is commonly known as 802.16 in the IEEE standard. WiMax is a technology that is based on this standard and provides wireless broadband access over long distances. It allows for high-speed internet connections and is often used in areas where wired connections are not feasible or cost-effective. WiBro and Zigbee are other wireless communication technologies, but they are not directly related to the 802.16 standard. Therefore, the correct answer is WiMax.Rate this question:
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- 44.
The current digital video specification that used video compression
- A.
MPEG 4
- B.
MPEG 1
- C.
MPEG 2
- D.
MPEG 3
Correct Answer
A. MPEG 4Explanation
MPEG 4 is the correct answer because it is the current digital video specification that is widely used for video compression. MPEG 4 provides efficient compression algorithms, allowing for high-quality video playback and streaming over various platforms and devices. It offers advanced features such as object-based coding, interactivity, and scalability, making it suitable for a wide range of applications including video conferencing, streaming services, and multimedia content delivery.Rate this question:
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- 45.
802.15.4 is also known as
- A.
Zigbee
- B.
WiMax
- C.
WiBro
- D.
None of the choices
Correct Answer
A. ZigbeeExplanation
802.15.4 is a standard for low-rate wireless personal area networks (WPANs). Zigbee is a communication protocol built on top of the 802.15.4 standard, specifically designed for low-power, low-data-rate, and short-range wireless communication. Therefore, Zigbee is the correct answer as it is a well-known and widely used technology that is based on the 802.15.4 standard. WiMax and WiBro are different wireless communication standards that operate in different frequency ranges and have different characteristics, so they are not equivalent to 802.15.4.Rate this question:
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- 46.
In radio communication, what is the point on a line between the earth’s center and an observer, located further from the earth’s center on a point?
- A.
Nadir
- B.
Zenith
- C.
Lowbe
- D.
Netar
Correct Answer
A. NadirExplanation
The correct answer is Nadir. In radio communication, the nadir is the point on a line between the Earth's center and an observer that is located further from the Earth's center. It is the opposite of the zenith, which is the point directly above the observer. The nadir is often used to refer to the lowest point or the point of greatest depression.Rate this question:
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- 47.
A camera tube that is formed from lead oxide (PbO)
- A.
Plumbicon
- B.
Saticon
- C.
Pasecon
- D.
Trinicon
Correct Answer
A. PlumbiconExplanation
Plumbicon is the correct answer because it is a type of camera tube that is made from lead oxide (PbO). Lead oxide is used in the construction of Plumbicon tubes because it has high sensitivity to light and can generate a high-quality video signal. Plumbicon tubes were commonly used in professional video cameras and offered better performance compared to other camera tube technologies such as Saticon, Pasecon, and Trinicon.Rate this question:
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- 48.
What part of visible spectrum where camera pick up that has the greatest output?
- A.
Yellow Green
- B.
White
- C.
Violet
- D.
Blue Green
Correct Answer
A. Yellow GreenExplanation
The camera picks up the part of the visible spectrum that has the greatest output in the Yellow Green range. This means that the camera is most sensitive to capturing light in this specific range, resulting in a higher output or intensity of colors in the Yellow Green region.Rate this question:
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- 49.
In a telephone channel, if the total via net loss of a given trunk circuits exceeds approximately 2.5 dB, a device known as ___________ is inserted.
- A.
Echo Suppressor
- B.
Echo Trimmer
- C.
Echo Filter
- D.
None of the choices
Correct Answer
A. Echo SuppressorExplanation
When the total via net loss of a given trunk circuit in a telephone channel exceeds approximately 2.5 dB, an Echo Suppressor is inserted. An Echo Suppressor is a device used to reduce or eliminate the echo that occurs during a phone call. It helps to improve the quality of the audio by suppressing the echo caused by the transmission of the signal.Rate this question:
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- 50.
In CMTS, the frequency separation between forward and reverse channel is
- A.
45 MHz
- B.
50 MHz
- C.
55 MHz
- D.
35 MHz
Correct Answer
A. 45 MHzExplanation
The correct answer is 45 MHz. In a CMTS (Cable Modem Termination System), the forward channel is used to transmit data from the service provider to the end user, while the reverse channel is used for data transmission from the end user to the service provider. The frequency separation between these two channels is important to prevent interference and ensure efficient communication. In this case, the frequency separation is 45 MHz, meaning that there is a gap of 45 MHz between the frequencies used for the forward and reverse channels.Rate this question:
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Current Version
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Mar 16, 2023Quiz Edited by
ProProfs Editorial Team -
Jun 28, 2013Quiz Created by
EcE_phoenix
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