Communication Systems Concepts Quiz

Radar signals and communication.

LEDs, lasers, and TV remotes are applications of infrared frequency.

AM broadcasting is an application of medium frequency.

<p>Higher input impedance and greater bandwidth.</p> Signup and view all the answers

<p>The radiation pattern is typically a figure-eight shape.</p> Signup and view all the answers

<p>Remote controls operate based on telemetry principles.</p> Signup and view all the answers

<p>Walkie-talkies enable simultaneous communication, while telephones typically require turn-taking.</p> Signup and view all the answers

<p>FAX devices allow the transmission of documents over telephone lines.</p> Signup and view all the answers

<p>The key functions of a transmitter include processing electrical signals, restricting the range of audio frequencies, amplifying the signal, and modulating the message signal onto a carrier wave.</p> Signup and view all the answers

<p>Modulation is primary because it superimposes the message signal onto a high-frequency carrier signal, making it suitable for transmission over long distances.</p> Signup and view all the answers

<p>Frequency limitation helps restrict the audio frequency range to ensure clarity and prevent distortion, typically up to 5 kHz in amplitude modulation radio broadcasts.</p> Signup and view all the answers

<p>Signal amplification is necessary in long-distance radio communication to strengthen the signal before modulation and transmission.</p> Signup and view all the answers

<p>The two additional processes are the restriction of audio frequency range and the amplification of the signal.</p> Signup and view all the answers

<p>Wire telephony typically requires minimal processing because the signals can be transmitted effectively without significant adjustments.</p> Signup and view all the answers

<p>In modulation, the message signal is superimposed onto the carrier signal, allowing the information to be transmitted over a distance.</p> Signup and view all the answers

<p>Processing eases the transmission by optimizing the signal's strength, frequency range, and modulation to ensure clarity over channels.</p> Signup and view all the answers

<p>The total power in the AM wave is $P_t = P_c(1 + m^2/2)$, where $P_c$ is the carrier power and $m$ is the modulation index. Thus, $P_t = 400(1 + (0.75^2)/2) = 400(1 + 0.140625) = 400(1.140625) = 456.25 W$.</p> Signup and view all the answers

<p>Atmospheric noise, also known as static noise, is caused by natural disturbances such as lightning and thunderstorms. An example source would be lightning strikes.</p> Signup and view all the answers

<p>Industrial noise originates from mechanical and electrical activities, with sources such as automobiles, aircraft, and electric motors. It can interfere with communication signals.</p> Signup and view all the answers

<p>Two types of extraterrestrial noise are solar noise and cosmic noise. Solar noise comes from solar flares, while cosmic noise originates from distant astronomical sources.</p> Signup and view all the answers

<p>Shot noise arises in active devices due to the random behavior of charge carriers, such as electrons. It occurs due to the random emission of electrons from cathodes in electron tubes.</p> Signup and view all the answers

<p>Simplex communication allows data transmission in one direction only, while duplex communication enables two-way data transmission. Duplex can be either half-duplex or full-duplex.</p> Signup and view all the answers

<p>Industrial noise interferes with the clarity of signals and can cause disruptions in communication. It originates from various electrical and mechanical processes.</p> Signup and view all the answers

<p>The modulation depth affects the amount of additional power contributed by sidebands in an AM wave. Greater modulation depth increases the total power, enhancing signal strength.</p> Signup and view all the answers