Question 1

Guided media,also called wireless,provide a physical means for guiding electromagnetic waves through seawater.

Accepted Answer

Guided media refers to communication channels that use physical wires or cables to transmit signals. Wireless, on the other hand, refers to communication channels that transmit signals through the air or space using electromagnetic waves. Therefore, the statement is false as guided media cannot be classified as wireless.

Question 2

The sine wave is the fundamental aperiodic signal.

Accepted Answer

The sine wave is a periodic signal, not an aperiodic signal. The simplest aperiodic signal is an impulse or a Dirac delta function.

Question 3

Delay distortion occurs because the velocity of propagation of a signal through a guided medium varies with frequency.

Accepted Answer

Delay distortion is a real phenomenon that can occur due to the velocity of propagation of a signal through a guided medium that varies with frequency. This can cause different frequencies within a signal to arrive at their destination at different times, resulting in distortion.

Question 4

For any given medium,the greater the bandwidth transmitted,the greater the cost.

Accepted Answer

Bandwidth refers to the amount of data that can be transmitted over a network or communication channel in a given amount of time. The greater the bandwidth required, the more expensive it may be to transmit the data, as it requires more infrastructure and resources to support higher bandwidth. Therefore, the statement is true.

Question 5

In ________ transmission signals are transmitted in only one direction; one station is the transmitter and the other is the receiver.

Accepted Answer

In simplex transmission, signals are transmitted in only one direction. This means that one station is the transmitter and the other is the receiver, and communication is one-way only. Examples of simplex communication include TV and radio broadcasting, where the broadcaster is transmitting the signal and individuals receive the signal on their devices.

Question 6

The greater the bandwidth of the signal the greater its information carrying capacity.

Accepted Answer

Bandwidth is the range of frequencies over which a signal is transmitted. The greater the bandwidth, the higher the number of frequencies or bits that can be transmitted per unit of time. Therefore, a signal with a greater bandwidth has a higher information carrying capacity.

Question 7

A major problem in designing a communications facility is transmission impairment.

Accepted Answer

Transmission impairment can occur due to factors like attenuation, noise, distortion, and interference. It is a common challenge in the design of communication facilities.

Question 8

A familiar example of analog data is audio,which,in the form of acoustic sound waves,can be perceived directly by human beings.

Accepted Answer

Audio is indeed an example of analog data that can be perceived directly by human beings in the form of acoustic sound waves.

Question 9

Analog signals suffer more from attenuation than do digital signals.

Accepted Answer

Attenuation affects both analog and digital signals, but digital signals can be regenerated to their original state, making them less susceptible to attenuation over long distances compared to analog signals.

Question 10

There is not a direct relationship between data rate and bandwidth.

Accepted Answer

The data rate, or bit rate, is directly related to bandwidth. A higher bandwidth allows for a higher data rate, meaning more data can be transmitted over a communication channel in a given amount of time.

Question 11

The term ________ is used to refer to the transmission path between two devices in which signals propagate directly from transmitter to receiver with no intermediate devices other than amplifiers or repeaters used to increase signal strength.

Accepted Answer

The term "direct link" specifically refers to a transmission path between two devices without any intermediate devices except for amplifiers or repeaters. This concept is distinct from guided media, which includes cables and wires, and wireless or unguided media, which includes radio waves and microwaves.

Question 12

The frequency is the rate at which the signal repeats.

Accepted Answer

The frequency of a signal is defined as the number of complete cycles of the waveform that occur per unit of time, and is typically measured in hertz (Hz). Therefore, the statement is true.

Question 13

In full-duplex operation both stations may transmit,but only one at a time.

Accepted Answer

In full-duplex operation, both stations can transmit and receive simultaneously, allowing communication in both directions at the same time.

Question 14

A(n)________ signal is a continuously varying electromagnetic wave that may be propagated over a variety of media,depending on spectrum.Examples are wire media and fiber optic cable.

Accepted Answer

An analog signal is a continuously varying electromagnetic wave that can be propagated over a variety of media, including wire media and fiber optic cable. Digital signals, on the other hand, are discrete and non-continuous. Periodic and aperiodic signals describe the repetitive or non-repetitive nature of a signal's waveform, respectively, and are not relevant to the propagation media.

Question 15

The advantages of digital signaling are that it is generally cheaper than analog signaling and is less susceptible to noise interference.

Accepted Answer

Digital signaling is generally cheaper than analog signaling because it utilizes less complex hardware and can be easily replicated. Additionally, digital signals are less susceptible to noise interference because they are transmitted as discrete, distinct values rather than continuous waveforms, making it easier to filter out unwanted noise.

Question 16

A guided transmission medium is ________ if it provides a direct link between two devices and those are the only two devices sharing the medium.

Accepted Answer

A point-to-point transmission medium such as a dedicated leased line provides a direct link between two devices and those are the only two devices sharing the medium. This is different from a multipoint medium where multiple devices share the same medium, and simplex and wireless transmissions refer to different aspects of communication.

Question 17

A digital signal is one in which the signal intensity maintains a constant level for some period of time and then abruptly changes to another constant level.

Accepted Answer

This statement accurately describes the characteristic of a digital signal, where the signal takes on discrete values and maintains those values for a given period of time before changing abruptly to another discrete value.

Question 18

Only digital signals can be used to convey information in the communications environment.

Accepted Answer

Both digital and analog signals can be used to convey information in the communications environment. Analog signals are continuously varying while digital signals are discrete levels.

Question 19

An analog signal can be transmitted only a limited distance before attenuation,noise,and other impairments endanger the integrity of the data.

Accepted Answer

The answer of An analog signal can be transmitted only...

Question 20

A key parameter that characterizes any electromagnetic signal is ________,which is the width of the range of frequencies that comprises the signal.

Accepted Answer

Bandwidth is the width of the range of frequencies that comprises the signal. Analog and digital refer to the type of signal encoding, while wavelength is a specific property of electromagnetic radiation related to its frequency.

Quiz 3: Data Transmission