esa-sceva/satcom-mcqa huggingface dataset:
Topic: Circular Polarization
Question: Why do high-frequency systems using linear polarization require a clear line-of-sight (LOS) path for effective operation?
Option 1: Because reflected linear signals often return out of phase with the direct signal, causing signal weakening and poor propagation through obstructions.
Option 2: Because high-frequency signals using linear polarization can easily diffract around obstacles.
Option 3: Because reflections from surfaces amplify the signal strength at the receiving antenna.
Option 4: Because linear polarization allows signals to maintain their original phase after reflection.
Option 5: Because high-frequency systems can rely entirely on multipath reflections for communication.
Answer: Option1
Topic: Circular Polarization
Question: Why do linearly polarized antennas experience signal loss when reflections occur from certain surfaces?
Option 1: Because reflections that do not occur in the same polarization plane result in a loss of signal strength.
Option 2: Because linear polarization automatically converts to circular polarization after reflection.
Option 3: Because linearly polarized antennas can operate effectively in all polarization planes.
Option 4: Because reflections always increase signal gain regardless of plane mismatch.
Answer: Option1
Topic: Beamforming
Question: why do phase shifters work best for narrower system bandwidths?
Option 1:  A phase shifter setting may result in different beam steering angles for different frequencies.
Option 2: A phase shifter setting does not affect beam direction, only the signal amplitude.
Option 3: A phase shifter setting locks all frequencies to the same beam angle, eliminating steering flexibility.
Option 4: A phase shifter setting changes the polarization of the signal, not the beam angle.
Answer: Option1
Topic: Onboard processing
Question: Why do some satellites have onboard processing (OBP) as part of the communication subsystems?
Option 1: To provide error detection and error correction to improve the quality of the communication
links.
Option 2: To provide only error correction, without any error detection, to improve the quality of the communication links.
Option 3: To provide encryption and compression, rather than error detection or correction, to improve link quality.
Answer: Option1
Topic: TT&C
Question: Why does a satellite transmitting antenna focus its signal on a narrower area rather than broadcasting equally in all directions?
Option 1: To concentrate power on a specific service zone (footprint) of a transponder, improving signal strength and coverage efficiency.
Option 2: To reduce the need for onboard power by broadcasting equally in all directions.
Option 3: To intentionally create coverage gaps between service zones.
Answer: Option1
Topic: Link Budget
Question: Why does ECRTP perform well under low error intensities?
Option 1: Because it does not suffer from packet loss due to desynchronization.
Option 2: Because it eliminates all transmission errors regardless of error intensity.
Option 3: Because it converts all UDP traffic into TCP traffic.
Option 4: Because it only operates on high-error-intensity channels.
Option 5: Because it ignores header compression entirely.
Answer: Option1
Topic: Telecommunication Payload
Question: Why does increasing the queue size improve the utilization of a bottleneck link in a TCP network?
Option 1: The utilization of the bottleneck link improves with increased queue size, because, under congestion, large queues keep
 the link busy as they drain out while TCP sources back off their sending window. 
Option 2: Larger queues allow TCP sources to ignore congestion entirely and send data at full speed.
Option 3: Increasing queue size reduces link utilization by creating more idle periods.
Option 4: Queue size does not affect link utilization in TCP networks at all.
Option 5: Large queues automatically prioritize certain TCP flows over others, improving utilization.
Answer: Option1
Topic: Circular Polarization
Question: Why does radio signal absorption vary when signals interact with different materials?
Option 1: Because different materials absorb radio signals differently depending on the signal’s polarization plane.
Option 2: Because all materials reflect and absorb radio waves equally regardless of their properties.
Option 3: Because the absorption depends only on the signal frequency, not on the material.
Option 4: Because radio signals cannot penetrate or be absorbed by any material.
Option 5: Because absorption occurs only when the material is metallic.
Answer: Option1
Topic: Non-Terrestrial Networks
Question: Why does satellite-based NTN introduce additional latency in mobility signaling compared to terrestrial networks?
Option 1: Because propagation delays in satellite links are much higher, affecting measurement reporting, handover command reception, and handover request/acknowledgment.
Option 2: Because terrestrial networks always use slower routing protocols.
Option 3: Because satellites perform no signal processing.
Option 4: Because handovers in NTNs do not require signaling.
Answer: Option1
Topic: Bit error rate
Question: Why does wireless link performance degrade in systems using compression?
Option 1: Because high bit error rates cause frequent loss of synchronization between the compressor and decompressor.
Option 2: Because wireless links always have zero latency.
Option 3: Because compression algorithms do not work over wireless links at all.
Option 4: Because the signal-to-noise ratio is irrelevant for compression performance.
Option 5: Because wireless links eliminate packet loss automatically.
Answer: Option1
Topic: Satellite Bandwidth
Question: Why has congestion become a serious issue in the lower frequency bands?
Option 1: Because of satellites’ increased use, number and size, congestion has become a serious issue in the lower frequency bands.
Option 2: Because lower frequency bands have unlimited spectrum and no interference concerns.
Option 3: Because satellites only operate in optical and extremely high-frequency bands.
Option 4: Congestion occurs only in terrestrial fiber-optic networks, not in satellite bands.
Option 5: Lower frequency bands are immune to interference and cannot experience congestion.
Answer: Option1
Topic: SNR
Question: Why is a high Signal-to-Noise Ratio (SNR) important for seismologists during earthquake data collection?
Option 1: A high SNR 
of 10 is pivotal for seismologists to assess the quality of seismic data recorded during an earthquake.
Option 2: High SNR is used to increase the magnitude of the earthquake, not assess data quality.
Option 3: SNR is irrelevant in seismology because all seismic signals are naturally strong.
Option 4: A high SNR decreases the sensitivity of seismometers, making data harder to interpret.
Answer: Option1
Topic: SNR
Question: Why is a higher Signal-to-Noise Ratio (SNR) essential in telecommunications?
Option 1: A higher SNR is essential in telecommunications because it ensures the quality and reliability of voice and data transmission, which is critical in everyday 
communication, internet connectivity, and various data transfer applications. 
Option 2: Because it reduces signal strength, helping to minimize interference in low-power systems.
Option 3: Because it increases noise levels, allowing easier detection of weak signals.
Answer: Option1
Topic: Downlink
Question: Why is a resource management mechanism essential in a satellite downlink carrying heterogeneous services?
Option 1: Because multiple streams are multiplexed together, and per-stream QoS must be ensured.
Option 2: Because satellites do not multiplex streams and each stream is transmitted separately.
Option 3: Because QoS is irrelevant for satellite downlinks carrying heterogeneous services.
Option 4: Because only a single type of service is transmitted, so per-stream QoS is unnecessary.
Answer: Option1
Topic: SNR
Question: Why is a strong Signal-to-Noise Ratio (SNR) important in data transmission?
Option 1: In data transmission, a strong SNR is critical for faster data transfer rates and reduced data packet loss.
Option 2: A strong SNR slows down data transfer because higher signal power increases latency.
Option 3: A strong SNR primarily increases quantization errors, degrading data quality.
Option 4: A strong SNR has no effect on data transfer rates or packet loss; it only affects signal strength.
Option 5: A strong SNR is only relevant for analog voice transmission, not digital data transfer.
Answer: Option1
Topic: Bit error rate
Question: Why is achieving very high availability rates in communication systems often expensive?
Option 1: Achieving availability rates of 99.95% at very low bit error rates (BER) requires redundant systems, higher power, and robust link designs, which increase cost.
Option 2: Because higher availability reduces the need for redundancy, leading to increased signal loss and maintenance costs.
Option 3: Because maintaining 99.95% availability requires lower transmission power and simpler system configurations.
Option 4: Because improving BER only depends on software optimization, which is inexpensive.
Answer: Option1
Topic: SNR
Question: Why is an allowance made in satellite communication systems for modulators and demodulators?
Option 1: To account for practical implementation imperfections and small degradations introduced by the satellite channel.
Option 2: To completely eliminate all signal degradation and achieve ideal performance.
Option 3: To ignore the effects of the satellite channel on signal quality.
Answer: Option1
Topic: Beamforming
Question: Why is beamforming required?
Option 1: Beamforming efficiently uses power and reduces interference.
Option 2: Beamforming is used to increase the satellite’s orbit altitude rather than improving signal efficiency.
Option 3: Beamforming eliminates the need for antennas, allowing omnidirectional transmission.
Option 4: Beamforming is applied to encode data into packets, unrelated to power or interference management.
Option 5: Beamforming increases signal attenuation to reduce received power at user terminals.
Answer: Option1
Topic: NTN
Question: Why is cross-border coordination mandatory for Non-Terrestrial Networks (NTN)?
Option 1: Cross border coordination is mandatory since NTN using satellites cover areas that span different countries. 
Option 2: Because NTN satellites only operate within a single country, so no coordination is needed.
Option 3: Because terrestrial networks do not require cross-border spectrum agreements.
Answer: Option1
Topic: Link Budget
Question: Why is CRTP highly effective over error-free links with low round-trip delay?
Option 1: Because it compresses IP/UDP/RTP headers down to 2 octets, reducing overhead and improving efficiency.
Option 2: Because it eliminates the need for IP, UDP, and RTP headers entirely.
Option 3: Because it increases header size to improve error detection.
Option 4: Because it only works for TCP traffic, not UDP or RTP.
Answer: Option1
Topic: DVB-S2
Question: Why is DVB-S2 considered flexible in satellite communications?
Option 1: Because it can adapt to any satellite transponder characteristics, supporting a wide range of spectrum efficiencies and associated SNR requirements.
Option 2: Because it only works with a single fixed transponder configuration.
Option 3: Because it ignores SNR and transponder limitations entirely.
Answer: Option1
Topic: Bit error rate
Question: Why is increasing transmission power not always a viable method to raise the energy per bit?
Option 1: Because it can cause interference with other systems.
Option 2: Because higher power transmission reduces signal strength.
Option 3: Because it completely eliminates noise from the channel.
Answer: Option1
Topic: Non-Terrestrial Networks
Question: Why is it important to address cross-border issues between countries choosing NTN and TN in certain 3GPP frequency bands?
Option 1: To ensure proper spectrum coordination and avoid interference in bands such as 3GPP band 1 and band 65/n65.
Option 2: Because NTN and TN systems never share frequency bands, so cross-border coordination is unnecessary.
Option 3: Because cross-border issues only apply to terrestrial networks, not satellite networks.
Option 4: Because spectrum regulation is identical worldwide and requires no coordination.
Option 5: Because interference is only a concern in unlicensed bands, not 3GPP licensed bands.
Answer: Option1
Topic: Bit error rate
Question: Why is it important to balance availability and cost in satellite communication systems?
Option 1: Because achieving very high availability (e.g., 99.95%) at low BER significantly increases satellite link costs, while slightly lowering availability can greatly reduce expenses.
Option 2: Because higher availability always results in lower costs due to improved efficiency.
Option 3: Because availability rates above 99% are unnecessary for any satellite communication service.
Option 4: Because cost and availability are unrelated parameters in satellite link design.
Answer: Option1
Topic: Signal-to-noise ratio
Question: Why is Signal-to-Noise Ratio (SNR) important in astronomy and radio astronomy?
Option 1: Astronomy and radio astronomy are scientific fields where Signal-to-Noise Ratio (SNR) plays a crucial role in detecting and studying celestial objects and signals from space.
Option 2: It allows astronomers to completely eliminate all noise from the data.
Option 3: It increases the speed at which celestial objects move in space.
Option 4: It replaces the need for telescopes or antennas in detecting signals
Option 5: It ensures that only visible light signals can be detected, ignoring radio waves.
Answer: Option1
Topic: Signal-to-noise ratio
Question: Why is Signal-to-Noise Ratio (SNR) important in audio engineering?
Option 1: In audio engineering, SNR is pivotal for achieving high-fidelity sound reproduction. It allows for the distinction of audio signals from background noise, creating enjoyable listening experiences. 
Option 2: Because it increases the amount of intentional distortion added to enhance sound effects.
Option 3: Because a lower SNR ensures that background noise is more prominent, improving sound realism.
Option 4: Because SNR primarily controls speaker power output, not audio clarity.
Answer: Option1
Topic: Signal-to-noise ratio
Question: Why is Signal-to-Noise Ratio (SNR) important in medical imaging and telemedicine?
Option 1: A strong SNR ensures clear and accurate diagnostic images in MRI and ultrasound, and high-quality video/audio communication in telemedicine.
Option 2: SNR is only relevant for audio signals, not imaging.
Option 3: SNR decreases image quality in MRI and ultrasound.
Option 4: SNR is irrelevant in telemedicine because network speed is the only factor.
Answer: Option1
Topic: SNR
Question: Why is Signal-to-Noise Ratio (SNR) important in voice recognition technology?
Option 1: Because it helps distinguish spoken words from background noise, which is crucial for accurate speech recognition.
Option 2: Because it only affects the volume of the speaker’s voice.
Option 3: Because SNR is irrelevant; speech recognition works the same in noisy and quiet environments.
Option 4: Because it determines the encoding format of the audio signal.
Option 5: Because it reduces the word vocabulary of the recognition system.
Answer: Option1
Topic: Communication Latency
Question: Why is TCP considered less suitable for satellite networks?
Option 1: Because large latency, high bit error rates, and asymmetric bandwidth degrade its performance over satellite links.
Option 2: Because TCP performs perfectly regardless of latency or errors.
Option 3: Because satellite networks always use TCP with no modifications.
Option 4: Because TCP only works over optical fiber networks.
Answer: Option1
Topic: Communication Latency
Question: Why is TCP less suitable for satellite networks?
Option 1: Because large latency, high bit error rates, and asymmetric bandwidth typical of satellite links negatively impact TCP performance.
Option 2: Because TCP does not work over any wireless network.
Option 3: Because satellite networks have zero latency and unlimited bandwidth.
Answer: Option1
Topic: Satellite broadcasting
Question: Why is the C-band valued in satellite communication systems?
Option 1: C-band is valued for its low rain fade and wide coverage, making it a dependable choice for large-scale communications infrastructure.
Option 2: Because it operates at very high frequencies, providing narrow beams and limited coverage areas ideal for point-to-point links.
Option 3: Because it eliminates the need for ground stations, relying entirely on inter-satellite communication.
Answer: Option1
Topic: Satellite Bandwidth
Question: Why is the deployment of synchronous transmission systems considered straightforward?
Option 1: Because they can interwork with existing plesiochronous systems.
Option 2: Because they require entirely new infrastructure incompatible with previous systems.
Option 3: Because they eliminate the need for any synchronization.
Answer: Option1
Topic: Satellite bus
Question: Why is the launch process considered a critical phase for a satellite bus?
Option 1: Because the satellite must survive intense vibrations and accelerations, ensuring all components function properly once in orbit.
Option 2: Because the satellite generates its own power only during launch.
Option 3: Because satellites are fully operational only after several months in orbit.
Answer: Option1
Topic: SNR
Question: Why is the Signal-to-Noise Ratio (SNR) a critical factor in radio astronomy observations?
Option 1: Because radio emissions from space are extremely weak and can be easily masked by background noise.
Option 2: Because radio telescopes emit strong signals that must overcome interference.
Option 3: Because the telescope’s antenna size determines the transmission power.
Option 4: Because radio astronomy requires modulation of strong carrier waves.
Answer: Option1
Topic: Carrier-to-noise ratio
Question: Why is the trade-off between required carrier power and occupied bandwidth important in satellite link design?
Option 1: For satellite
links, the trade-off between required carrier power and occupied bandwidth is paramount to the cost-effective design of the link.
Option 2: Because increasing both power and bandwidth always reduces overall link efficiency and reliability.
Option 3: Because satellite links are unaffected by bandwidth limitations, making power the only consideration.
Option 4: Because minimizing both power and bandwidth maximizes transmission distance without affecting quality.
Answer: Option1
Topic: Link Budget
Question: Why is transmitter loss treated separately in a satellite link budget?
Option 1: Transmitter loss is treated separately since it affects the EIRP directly.
Option 2: Because transmitter loss only affects the receiver sensitivity, not the transmitted power.
Option 3: Transmitter loss is negligible and does not need separate consideration in any link budget.
Answer: Option1
Topic: Satellite broadcasting
Question: Why is two-way satellite communication necessary for interactive applications?
Option 1: Audio, video and data are broadcasted to final users by satellite in a oneway
communication, but two-way communication is needed for interactive applications.
Option 2: Because one-way communication already supports full interactivity between users and providers.
Option 3: Because two-way links are only needed for transmitting high-quality video signals.
Answer: Option1
Topic: Wireless communication systems
Question: Why is wireless control required in GEO satellite communication systems?
Option 1: To support control plane functions related to resource control and management of the physical, MAC, and data link control (DLC) layers during the establishment of a wireless link.
Option 2: To directly replace the transport layer protocols used for end-to-end communication.
Option 3: To manage user applications such as video streaming and web browsing.
Option 4: To enhance the optical signal processing for inter-satellite communications.
Option 5: To synchronize user data encryption across different frequency bands.
Answer: Option1
Topic: Handover procedure
Question: Why must handover procedures in satellite communication systems be executed very quickly?
Option 1: Because the satellites move at high orbital velocities and the overlap area between satellite coverages is small.
Option 2: Because the user terminals have limited buffer capacity.
Option 3: Because the propagation delay between satellites and ground stations is negligible.
Answer: Option1
Topic: Link Budget
Question: Why should all link budgets be verified before installing a satellite communication system?
Option 1: Link budgets can be replaced entirely by antenna size calculations, making measurements redundant.
Option 2: All link budgets should be 
verified via observed measurements before committing to an installation. 
Option 3: Verification is unnecessary because link budgets are theoretical and always accurate.
Option 4: Link budgets only need verification after system failure, not before installation.
Option 5: Observed measurements are only required for analog systems, not digital satellite links.
Answer: Option2
Topic: Satellite broadcasting
Question: Why was satellite networking considered as a solution to complement terrestrial broadband networks?
Option 1: Satellite networking was considered as an alternative solution to ‘broadband for all’ to complement terrestrial broadband networks due to its flexibility and immediate global coverage.
Option 2: Because it is slower and less reliable than terrestrial networks, making it suitable only for niche applications.
Option 3: Because it completely replaces terrestrial broadband without any need for ground infrastructure.
Option 4: Because satellites operate exclusively at low frequencies, unsuitable for broadband.
Answer: Option1
Topic: Carrier-to-noise ratio
Question: With which type of operation are SF (Single Frequency) and TF (Time-Frequency) signalling systems commonly associated?
Option 1: SF and TF signalling systems are often associated with carrier (FDM) operation.
Option 2: Purely optical fiber communication without any frequency multiplexing.
Option 3: Direct baseband transmission without carriers.
Option 4: Wireless LAN systems using CSMA/CA only.
Option 5: Satellite systems operating exclusively in TDMA mode without frequency carriers.
Answer: Option1
Topic: BER
Question:  A coding scheme reduces BER from 10^-3 to10^-6, the improvement is by factor:
Option 1: 10
Option 2: 100
Option 3: 1000
Option 4: 1,000,000
Option 5: 10,000
Answer: Option 3
Topic: Satellite gateway
Question:  A gateway uplink power of 40 dBW and system losses of 10 dB result in what received power at satellite if gain is 30 dBi? 
Option 1: 60 dBW
Option 2: 80 dBW
Option 3: 100 dBW
Option 4: 40 dBW
Answer: Option 1
Topic: 5G NTN
Question:  A LEO satellite orbits every 90 minutes. How many orbits in 24 hours?
Option 1: 12
Option 2: 16
Option 3: 18
Answer: Option 2
Topic: Telecommunication Payload
Question:  A payload has 100 MHz bandwidth and spectral efficiency of 2 bits/s/Hz. Calculate maximum data rate
Option 1: 50 Mbps
Option 2: 100 Mbps
Option 3: 150 Mbps
Option 4: 200 Mbps
Option 5: 400 Mbps
Answer: Option 4
Topic: Link Budget
Question:  A satellite's transmit power is increased from 10 W to 100 W. The received power increases by:
Option 1: 10 dB
Option 2: 20 dB
Option 3: 2 dB
Option 4: 5 dB
Option 5: 0 dB
Answer: Option 1
Topic: Link Budget
Question:  A system operating at 2.4 GHz has a wavelength of approximately
Option 1: 0.125 m
Option 2: 0.0125 m
Option 3: 12.5 m
Option 4: 1.25 m
Answer: Option 1
Topic: TCP over satellite
Question:  A TCP connection has a window size of 80 KB and RTT of 400 ms. Calculate throughput (in Kbps).
Option 1: 1600 Kbps
Option 2: 2000 Kbps
Option 3: 4000 Kbps
Answer: Option 2
Topic: Link Budget
Question:  Calculate carrier to noise density ratio (C/N0) if EIRP = 40 dBW, G/T = 20 dB/K, losses = 10 dB, K = 228.6 dB (thermal noise constant) 
Option 1: 31.4 dBHz
Option 2: 40 dBHz
Option 3: 50 dBHz
Answer: Option 1