Explore essential concepts of signal transmission with this quiz focused on noise, interference, and the fundamentals of communication channels. Improve your grasp of key terms and phenomena affecting reliable data transfer in telecommunications and data networks.
Which type of noise is mainly caused by random thermal agitation of electrons in a conductor, commonly affecting all electronic communication systems?
Explanation: Thermal noise arises from the random motion of electrons in all conductors and is present in all electronic devices, making it a fundamental form of noise. Impulse noise consists of sudden, irregular spikes often caused by switching or lightning. Crosstalk is interference from adjacent wires or channels. Shot noise is related to the discrete nature of electric charge in devices but is not the most common type.
When two adjacent communication cables induce unwanted signals into each other, especially in telephone wires, what is this phenomenon called?
Explanation: Crosstalk occurs when signals from one channel or cable induce voltages into another, often due to electromagnetic coupling, especially in unshielded cables. Attenuation refers to the reduction in signal strength over distance. Echo involves the reflection of signals, causing delayed repeats. Refraction deals with bending of waves as they pass through different media and is unrelated to induced signals.
How does limited bandwidth in a communication channel typically affect signal transmission quality?
Explanation: A channel's bandwidth limits the highest rate at which information can be reliably transmitted, constraining data flow. While phase distortion can occur in some cases, it is not the main issue with bandwidth limitation. Increased bandwidth, not reduced, leads to higher data transfer speeds. Bandwidth limitation does not eliminate noise; instead, it can sometimes exaggerate certain noise effects.
In a scenario where a nearby radio transmitter unintentionally disrupts Wi-Fi signals, this disruption is best classified as which of the following?
Explanation: Electromagnetic interference (EMI) originates from external electronic sources, such as radio transmitters, that disrupt normal signal transmission in nearby devices. Random noise is typically inherent and not caused by an external, specific source. Systematic error commonly refers to measurement or procedural errors, not unwanted signal disruption. Thermal agitation refers to noise produced internally by random motion, not external EMI.
Why is a higher signal-to-noise ratio (SNR) considered beneficial in digital communication systems?
Explanation: A higher SNR means the signal is stronger compared to the noise level, resulting in clearer and more reliable data reception. Reducing channel bandwidth might hamper data rate but is not a result of high SNR. Higher SNR actually decreases, not increases, data errors. Amplifying background noise is the opposite of what high SNR achieves.