IT300 MIDTERM REVIEW

Determine the data rate possible given 32-QAM modulation where M=32, and baud rate is 9.6 kbps. a. 4.8 kbps b. 48 kbps c. 14.4 kbps d. 1.44 kbps

b. 48 kbps

What is the difference between M-ary line coding and M-ary modulation? a. there is no difference b. M-ary line coding results in a baseband signal, while M-ary modulation results in a modulated digital signal c. M-ary line coding applies to digital baseband signals, while M-ary modulation applies to analog signals d. Hartley's Law applies to M-ary line coding but not to M-ary modulation

b. M-ary line coding results in a baseband signal, while M-ary modulation results in a modulated digital signal

In selecting a line coding technique, we consider the need for receive clock synchronization, as well as the frequency bandwidth occupied by the resulting signal. What is true about the Manchester line coding technique. a. Manchester occupies less frequency spectrum (i.e., frequency bandwidth), than simpler line coding techniques such as NRZ b. Manchester ensures signal transitions for each bit sent, thus helping to ensure receive clock synchronization; however, it occupies twice the frequency bandwidth compared to NRZ c. Manchester ensures greater receive clock synchronization and efficient bandwidth usage compared to NRZ d. there are no true statements listed above

b. Manchester ensures signal transitions for each bit sent, thus helping to ensure receive clock synchronization; however, it occupies twice the frequency bandwidth compared to NRZ

Determine the decibel value of SNR given a signal power, S=-100dBm, and noise power, N=-128dBm. a. SNR = -228 dB b. SNR = 28 dB c. SNR = -28 dB d. SNR = 228 dB

b. SNR = 28 dB

A DC circuit with is driven by 12 volt supply and a DC load of 200 Ohms. Calculate I (Amps) and P (Watts). a. 720 A, 60 W b. 2.4 mA, 28.8 mW c. 60 mA, 720 mW d. 12 A, 200 W

c. 60 mA, 720 mW

Given the following PM modulated signal equation, determine the frequency bandwidth. s(t)=3cos(2π13E9t + 2cos(2π13E3t)) a. 22kHz b. 40kHz c. 78 kHz d. 116 kHz

c. 78 kHz

What is correct regarding an ideal isotropic antenna? a. An ideal isotropic antenna is a highly efficient antenna used extensively in today's communication systems b. An ideal isotropic antenna is a specialized antenna used to direct EM signal energy towards a specific direction c. An ideal isotropic antenna is a theoretical antenna that does not exist in practice, but is useful in explaining power density and unguided EM signal attenuation d. None of the above are correct statements

c. An ideal isotropic antenna is a theoretical antenna that does not exist in practice, but is useful in explaining power density and unguided EM signal attenuation

Determine the decibel values of thermal noise power (N) and thermal noise power density (No) given the following: T=303 degrees Kelvin, B = 36MHz. (note: brackets "[ ]" represent decibel values) a. [N] = +128 dBW, [No]= +204dBm b. [N] = -128.22 dBW, [No] = -203.79 dBm c. [N] = -128.22 dBW, [No]= -173.79 dBm d. [N] = -98.22 dBm, [No]= -173.79 dBW

c. [N] = -128.22 dBW, [No]= -173.79 dBm

A carrier wave has an amplitude of 2 volts, a frequency of 120 kHz, and -π/2 radian phase angle. Select the correct carrier wave equation. a. c(t) = 2 cos(2π*12kHz*t - π) b. c(t) = 2cos(2π*120E3Hz*t + π) c. c(t) = 2cos(2π*120E3Hz*t - 1.57) d. None of the above are correc

c. c(t) = 2cos(2π*120E3Hz*t - 1.57)

Convert 1223 milliwatts to decibels referenced to 1mW. a. 32 dBW b. 30.9 dBW c. 0.9 dBm d. 30.9 dBm

d. 30.9 dBm

Determine the power density from an ideal isotropic antenna measured at a distance of 12 kilometers from the transmitting antenna, at a frequency of 100 MHz, and a transmit power of 10 watts: a. 5.53 w/m2 b. 5.53E-2 w/m2 c. 5.53E-8 w/m2 d. 5.53E-9 w/m2

d. 5.53E-9 w/m2

Select the correct statement(s) regarding Hartley's Law. a. Hartley's Law gives us a relationship between baud rate (symbols per second) and data rate (bits per second) Answers: a. Hartley's Law gives us a relationship between baud rate (symbols per second) and data rate (bits per second) b. by increasing "M", you also increase bit rate c. by increasing baud rate, you also increase bit rate d. all are correct statements

d. all are correct statements

Analog information can be converted into digital data using techniques such as PCM (pulse code modulation). Select the correct statement(s). a. in order to convert an analog signal that consists of an infinite number of values, it must be sampled using the Nyquist sampling theorem b. digitized analog signals always experience quantization loss c. signal aliasing is experienced when sampling falls below the recommended Nyquist sampling rate d. all of the above are correct

d. all of the above are correct

Network availability takes into consideration both the amount of time that the network fails and is not functioning, as well as the time it takes to bring the network back into full service. TRUE FASLE

FALSE

Optical signals are not part of the electromagnetic (EM) spectrum. Only radio frequency (RF) waves are considered part of the EM spectrum. TRUE FALSE

FALSE

Orthogonal Frequency Division Multiplexing (OFDM) is a spread spectrum technology. TRUE FALSE

FALSE

The noise floor includes thermal noise, impulse noise, intermodulation noise (IM), and cochannel interference (CCI). Link margins are only added to counter weather. TRUE FALSE

FALSE

A carrier is a periodic wave that can be represented by either a sine or cosine wave. Once the carrier is combined with a message (i.e., information) wave, the modulated carrier (i.e., passband or modulated signal wave) will have a frequency bandwidth that can be viewed in the frequency domain. TRUE FALSE

TRUE

A switched circuit is one in which a user maintains the physical path through a network during the period of a call. Once the user's call is complete, the communications path is made available to other users. TRUE FALSE

TRUE

A unipolar signal crosses zero, while a bipolar signal always remains positive. TRUE FALSE

TRUE

In unguided medium (free space), the electromagnetic (EM) signal wave spreads as it leaves the transmit antenna. Since the power of the EM signal resides at the surface area of the wave front, signal power is described as signal power density (i.e., watts per area). As the signal propagates away from the transmitter, power density decreases, and attenuation is experienced. TRUE FALSE

TRUE

It is useful to observe an information signal in both the time and frequency domains. The time domain gives us information about the signal's amplitude over time, while the frequency domain gives us information regarding signal frequency and bandwidth. TRUE FALSE

TRUE

Radio Frequency (RF) signals propagate as an electromagnetic (EM) wave. Optical signals behave as both a wave and as a particle as it propagates. Although optical waves possess this "wave-particle duality", they are still considered EM waves. TRUE FALSE

TRUE

Signal modulation is used to mix a baseband signal with a carrier wave for the purpose of relocating the modulated channel to the higher carrier frequency. TRUE FALSE

TRUE

The time varying components of capacitance and inductance results in reactive power elements that can decrease power transfer. TRUE FALSE

TRUE

When considering the impact of impulse noise, we find that it is more devastating to a digital communications link, than an analog one. Therefore, error control methods should be used on all digital links. TRUE FALSE

TRUE

When datagrams are exchanged using a connectionless virtual circuit, there is no guarantee that datagrams will arrive in proper sequence. It is left to the upper OSI layers to re-sequence received datagrams. TRUE FALSE

TRUE

When determining the decibel value of the signal-to-noise ratio (SNR), both the signal and noise floor power must be referenced to the same power units (i.e., both referenced to 1 watt or 1 milliwatt, etc.). However, SNR is a unitless ratio. TRUE FASLE

TRUE

With error control, n-k bits are added to a dataword (k-bits in length) to create a codeword (n-bits in length). TRUE FLASE

TRUE

34.5 watts = _______ mW a. 34,500 mW b. 15.3 dBm c. 45.37 dBW d. 34.5E-3 mW

a. 34,500 mW

Convert 300 watts to dBm a. 54.77 dBm b. 24.77 dBm c. 300 dBm d. 24.77 dBW

a. 54.77 dBm

6 GHz = _______ kHz. a. 6,000,000 kHz b. 6,000 kHz c. 600, 000 kHz d. 6E10 kHz

a. 6,000,000 kHz

You digitize an analog signal that has a frequency bandwidth of 20kHz, using a bit depth of 16. What data rate must be supported? a. 640 kbps b. 64 kbps c. 320 kbps d. 256 kbps

a. 640 kbps

Convert 47 dBW to dBm a. 77 dBm b. 17 dBm c. -17 dBm d. -17 dBW

a. 77 dBm

Select the correct statement(s) regarding FM. a. FM is considered "envelope modulation" because the amplitude of the modulated carrier does not change with the message b. AM is better than FM regarding noise rejection c. Bessel functions are used to determine modulated carrier amplitudes in the time domain d. all statements are correct

a. FM is considered "envelope modulation" because the amplitude of the modulated carrier does not change with the message

Select the correct statement(s) regarding amplitude modulation (AM). a. If the AM Index is greater than 1 (i.e., µAM>1), then overmodulation occurs leading to signal distortion b. With AM, the message is captured as carrier frequency changes c. The AM modulated carrier bandwidth is always equal to the baseband bandwidth d. All of the above are correct

a. If the AM Index is greater than 1 (i.e., µAM>1), then overmodulation occurs leading to signal distortion

Select the correct statement(s) regarding the difference between analog and digital signals. a. analog signals are comprised of an infinite number of amplitudes and time slices b. digital signals are only represented by discrete values of "0s" and "1s", and therefore can never convey analog information c. digital signals are more accurate than analog signals; this is why digital music sounds much better d. analog networks easily fit into the OSI Reference Model

a. analog signals are comprised of an infinite number of amplitudes and time slices

Select the correct statement(s) regarding impedance in a communications circuit. a. capacitance and inductance changes with signal frequency b. impedance is comprised of only real resistive components c. the greater the reactance in a circuit, the less the overall resistance of within the circuit d. all are correct statements

a. capacitance and inductance changes with signal frequency

A ___________ data compression technique results in some of the original data being lost. a. lossy b. lossless c. analog d. PCM

a. lossy

Given the following AM modulated signal, determine the original message, m(t): s(t) = 2.5[1+0.5 cos(2π25kHz*t)] cos(2π88MHz*t) a. m(t) = 1.25cos(2π25kHz*t) b. m(t) = 1.25cos(2π88MHz*t) c. m(t) = 2.5cos(2π25kHz*t) d. m(t) = 2.5cos(2π88MHz*t)

a. m(t) = 1.25cos(2π25kHz*t)

Identify the device that combines multiple time slots or frequency channels into an aggregate for transmission. a. multiplexer b. modem c. repeater d. switch

a. multiplexer

An analog signal with a bandwidth of 36MHz is sampled at a frequency (fs) of 36,000,000 samples per second during the ADC (analog-to-digital conversion) process. What is the outcome of the received signal after the DAC (digital-to-analog conversion) process? a. the signal will have experienced aliasing b. the signal will not experience aliasing c. the signal will perfectly represent the original pre-ADC analog signal d. none of the above describes the outcome

a. the signal will have experienced aliasing

Identify the correct equation that describes the relationship between a sine and a cosine wave. a. v(t) = A sin (2πft + π/2) = A cos (2πft) b. v(t) = A sin (2πft) = A cos (2πft + π/2) c. v(t) = A sin (2πft ) = A cos (2πft) d. v(t) = A sin (2πft - π/2) = A cos (2πft)

a. v(t) = A sin (2πft + π/2) = A cos (2πft)

Convert -33 dBW to milliwatts a. 3 mW b. 0.5 mW c. -50 mW d. -3 mW

b. 0.5 mW

Given the following information, determine the [SNR] in decibel form: [Pr] = [S] = -70dBm, T=300oKelvin, B=36MHz a. -173.83 dB b. 28.27 dB c. -98 dB d. 98 dB

b. 28.27 dB

A signal has a frequency range from 300Hz to 3.4kHz. What is the frequency bandwidth in Hz? a. 1300E6 Hz b. 3100 Hz c. 1.6 kHz d. 130 MHz

b. 3100 Hz

A five-bit dataword can represent how many encoded symbols (i.e., A, B, C, 1, 2, 3, etc.)? a. 16 symbols b. 32 symbols c. 64 symbols d. 128 symbols

b. 32 symbols

A modulated signal represents digital data using a set of frequencies {f1, f2, f3, f4, f5, f6, f7, f8}. What is the digital modulation technique and how many bits can a single symbol represent? a. FSK, 2 bits per symbol b. FSK, 3 bits per symbol c. PSK, 4 bits per symbol d. PSK, 2 bits per symbol

b. FSK, 3 bits per symbol

Given the following AM modulated signal, determine the occupied frequency bandwidth (note: assume double-sideband large carrier (DSB-LC): s(t) = 2.4[1+0.7 cos(2π33Hz*t)] cos(2π10GHz*t) a. Frequency bandwidth = 33 Hz b. Frequency bandwidth = 66 Hz c. Frequency bandwidth = 10GHz d. Frequency bandwidth = 20GHz

b. Frequency bandwidth = 66 Hz

What is the purpose of a transducer? a. They are used to transform potential energy (joules) into power (watts) b. Transducers are used to convert one form of signal energy into another form of signal energy. As an example, a microphone is an example of a transducer. c. Transducers are used to convert DC signals into an alternating (AC) signal d. None of the above are correc

b. Transducers are used to convert one form of signal energy into another form of signal energy. As an example, a microphone is an example of a transducer.

Select the true statement regarding Amplitude Modulation (AM). a. when using DSB-LC AM modulation, the frequency bandwidth is fm b. both DSB-LC and DSB-SC have a frequency bandwidth of 2fm c. SSB modulation provides the highest quality AM signal d. there are no true statements

b. both DSB-LC and DSB-SC have a frequency bandwidth of 2fm

How do coaxial cables prevent RF interference? a. by adopting a balanced signal configuration b. by use of a properly grounded conductive shielding surrounding the signal wire c. by implementing noise cancellation techniques d. all of the above

b. by use of a properly grounded conductive shielding surrounding the signal wire

What is true about delay skew? a. delay skew is only a problem with coaxial cables b. delay skew exists in UTP cables (e.g., Cat 5E) where each wire pair is twisted at different twist ratios c. delay skew only exists in unguided systems where path reflection causes signal copies to reach the receiver at different times d. delay skew is another term for signal propagation

b. delay skew exists in UTP cables (e.g., Cat 5E) where each wire pair is twisted at different twist ratios

Given a wavelength of λ=1000 meters, determine the frequency and signal time period. a. f=30 kHz, T=3.34E-6 seconds b. f=300 kHz, T=3.34E-6 seconds c. f=3000 kHz, T=3.34E-8 seconds d. f=30,000 kHz, T=3.34E-9 second

b. f=300 kHz, T=3.34E-6 seconds

Given the following parameters, select the correct equation for the amplitude modulated (AM) carrier signal. Am=6.5v, Ac=7v, fm=3500Hz, fc=100kHz, φm=0, φc=0 a. s(t) = 7[1+1.08 cos(2π3500t)] cos(2π100E3t) b. s(t) = 7[1+0.93 cos(2π3500t)] cos(2π100E3t) c. s(t) = 7[1+6.5 cos(2π3500t)] cos(2π100t) d. s(t) = 6.5[1+0.93 cos(2π100t)] cos(2π100E3t)

b. s(t) = 7[1+0.93 cos(2π3500t)] cos(2π100E3t)

Given the following message, m(t), carrier, c(t), and Kp=0.1(rad/v), determine the PM modulated signal equation and PM index. m(t)=2cos(2π4000t), c(t)=4cos(2π8MHzt). a. s(t)=4cos(2π4E6t + 0.75cos(2π3500t)), µPM=0.75 b. s(t)=4cos(2π8E6t + 0.2cos(2π4E3t)), µPM=0.2 c. s(t)=3cos(2π4E6t + 0.75cos(2π3500t)), µPM=0.75 d. s(t)=4cos(2π4000t + 0.2cos(2π8E6t)), µPM=0.2

b. s(t)=4cos(2π8E6t + 0.2cos(2π4E3t)), µPM=0.2

Select the correct statement(s) regarding frequency modulation (FM) bandwidth. a. the more the carrier frequency is allowed to change frequencies (Δf), the smaller the modulated signal bandwidth b. the larger the FM index, β, the larger the modulated signal bandwidth c. as you increase kvco, you decrease modulated signal bandwidth d. all statements are correct

b. the larger the FM index, β, the larger the modulated signal bandwidth

Calculate the amplitude of a sinusoidal signal at t=8E-03s given the following equation: c(t) = 5 cos(2π(60Hz)t + π/2) a. 1.67E-2 b. 5 c. -6.3E-1 d. 0.04

c. -6.3E-1

Determine the maximum theoretical data rate possible given a frequency bandwidth of 22MHz, SNR=101, and M=8. a. 27 Mbps b. 91 Mbps c. 147 Mbps d. 285 Mbps

c. 147 Mbps

56 watts = ______ dBW a. 47.48 dBW b. 17.5 dBm c. 17.48 dBW d. 26 dBW

c. 17.48 dBW

16QAM tells us that a single symbol equals _____ logical bits. a. 2 b. 3 c. 4 d. 5

c. 4

A single symbol represents the following logical values: 00, 01, 10, 11. At a baud rate of 2400, what is the resulting bit rate using Hartley's Law? a. 1200 bps b. 2400 bps c. 4800 bps d. 9600 bps

c. 4800 bps

Select the true statement regarding error control algorithms. a. ARQ is solely an error detection algorithm b. the concept of codeword and dataword is only applicable to error correction c. CRC is an error detection method that requires the use of a shared polynomial between communicating nodes d. PCM is a prime example of an error detection method

c. CRC is an error detection method that requires the use of a shared polynomial between communicating nodes

_________ is noise caused when the same frequency is used by adjacent transmitters that interfere with one another. a. Thermal noise (N) b. Intermodulation noise (IM) c. Cochannel interference (CCI) d. Impulse noise

c. Cochannel interference (CCI)

Select the correct statement(s) regarding DCE and DTE interfaces. a. DTE and DCE describes the device types (e.g., computers, switches, routers, etc.) b. distinguishing between DTE and DCE is only required for half-duplex communications c. DTE and DCE describes the interface and direction of data flow between devices; a single device may have both types of interfaces d. all statements are correct

c. DTE and DCE describes the interface and direction of data flow between devices; a single device may have both types of interfaces

Select the correct statement(s) regarding FDM and TDM. a. FDM and TDM are both identical in the way channels are aggregated; therefore their terms can be used interchangeably b. FDM aggregates channels by separating each by time slots, whereas TDM aggregates channels by frequency c. FDM separates channels in the frequency domain, whereas TDM separates time slots in the time domain d. TDM requires guard channels in between information channels, whereas FDM does not require the use of guard channels

c. FDM separates channels in the frequency domain, whereas TDM separates time slots in the time domain

A telephone is an example of: a. Simplex Communications b. Half Duplex Communications c. Full Duplex Communications d. Complex Communications

c. Full Duplex Communications

Select the correct statement(s) regarding EM waves. a. EM depolarization enables frequency reuse b. RHCP and LHCP are EM waves that are considered linearly polarized c. RHCP or LHCP waves can be created by transmitting the same signal, separated by 90 degrees, using orthogonal polarizations d. all of the statements are correct

c. RHCP or LHCP waves can be created by transmitting the same signal, separated by 90 degrees, using orthogonal polarizations

Determine the decibel value of SNR given a signal power, S=-100dBm, and noise power, N=-133dBW. a. SNR = -100dBm - (-98dBW) = -2 dB b. SNR = (-100dBm + 30)dBW - (-133 dBW) = +28 dBW c. SNR = (-100dBm - 30)dBW - (-133 dBW) = 3 dBW d. SNR = (-100dBm - 30)dBW - (133 dBW) = -263 dBW

c. SNR = (-100dBm - 30)dBW - (-133 dBW) = 3 dBW

Select the correct statement regarding acoustic and electrical signals a. Acoustic wave propagate at the speed of light (3E8 m/s) b. Electrical waves depend upon the existence of air molecules in order to propagate c. Transducers are required to turn acoustic signals into an electrical signal d. Acoustic signals are electrical signals

c. Transducers are required to turn acoustic signals into an electrical signal

Given a receive power of 7E-5 mW and a noise power in decibels of N= 144E-13 W, determine the decibel SNR value. Answers: a. [SNR] = -173.5 dB b. [SNR] = +66.87 dB c. [SNR] = +36.87 dB d. [SNR] = +84.03 dB

c. [SNR] = +36.87 dB

Select the correct statement(s) regarding symbol rate (baud rate) and bit rate (bits per second). a. a single logical bit can represent one or more symbols b. symbol rate is another term for bit rate - they are the same c. a symbol can represent one or more logical bits d. all are correct statements

c. a symbol can represent one or more logical bits

Select the correct statement(s) regarding the Shannon-Hartley Capacity Theorem. a. data rate capacity is a function of carrier frequency and signal bandwidth b. the theoretical Shannon capacity identifies the lowest data rate capacity achievable; today's digital systems can reach capacities much greater than the Shannon limit. c. according to the theorem, an increase in signal bandwidth or SNR results in an increase in bit rate capacity d. all of the above are correct statements

c. according to the theorem, an increase in signal bandwidth or SNR results in an increase in bit rate capacity

Select the correct statement(s) regarding packet switching. a. connectionless packet communications requires that a connection first be established prior to the exchange of data b. the packet switching concept requires the establishment of dedicated physical circuits c. connection-oriented circuits must use overhead to establish communications prior to data exchanges between nodes d. all statements are correct

c. connection-oriented circuits must use overhead to establish communications prior to data exchanges between nodes

Identify the correct statement(s) regarding dedicated circuits. a. because call setup is not required, dedicated circuits are very efficient b. dedicated and circuit switched concepts are identical c. dedicated circuits are used between specific locations where 24/7 connectivity is needed d. all statements are correct

c. dedicated circuits are used between specific locations where 24/7 connectivity is needed

Select the correct statement(s) regarding circuit switching. a. the circuit switching concept is only used on full mesh network architectures b. circuit switching can only be used on digital networks where each packet contains both source and destination addresses c. during a circuit switched connection, a physical path through the network is established, but only for the duration of the call d. no correct statements

c. during a circuit switched connection, a physical path through the network is established, but only for the duration of the call

The period of a carrier wave is T=0.005 seconds. Determine the frequency and wavelength of the carrier wave. a. f=20 Hz, λ=3E8 meters b. f=200 Hz, λ=1.5E7 meters c. f=200 Hz, λ=1.5E6 meters d. f=400 Hz, λ=150E3 meters

c. f=200 Hz, λ=1.5E6 meters

What makes a fiber optic (FO) cable work? a. total internal reflection (TIR) is achieved provided the core and cladding have the same refractive indices b. FO light propagation only occurs when there is line-of-sight (LOS) between the source and detector c. light propagation occurs when the refractive index of the core differs from the refractive index of the cladding d. none of the above

c. light propagation occurs when the refractive index of the core differs from the refractive index of the cladding

Given the following PM modulated signal equation, determine the original message equation, m(t). s(t)=3.2cos(2π2E9t + 0.99cos(2π5000t)), Kp=0.33 (Hz/v) a. m(t)= 4.4cos(2π5000t) b. m(t)= 4.4cos(2π2E9t) c. m(t)= 3cos(2π5000t) d. m(t)= 3.2cos(2π2E9t)

c. m(t)= 3cos(2π5000t)

Select the true statement(s) regarding a virtual circuit. a. both analog and digital networks take advantage of the virtual circuit concept b. virtual circuits require the assignment of dedicated physical links during network connection c. regarding the efficient use of physical links, virtual circuits are more efficient than analog circuits d. both a and b are true statements

c. regarding the efficient use of physical links, virtual circuits are more efficient than analog circuits

What does a BER of 10-4 mean? a. there will be no errors during transmission since the BER is so low b. there is a probability of one error for every 100,000 bits transmitted c. there is a probability of one error for every 10,000 bits transmitted d. does not mean anything unless associated with a transmission data rate (bit rate)

c. there is a probability of one error for every 10,000 bits transmitted

Given the following parameters, determine the correct sinusoidal equation for a sine wave: f=10kHz, A=3v, φ (phase angle)=+π/4 radians. a. 3sin(2π10t - π/4) b. 10sin(2π3t) c. 10sin(2π3t + π/4) d. 3sin(2π10,000t + π/4)

d. 3sin(2π10,000t + π/4)

Given the following FM modulated signal equation, determine the frequency bandwidth. s(t)=1cos(2π36GHz*t + 4sin(2π4kHz*t)) a. 36 kHz b. 4 kHz c. 1 kHz d. 40 kHz

d. 40 kHz

Select the correct statement(s) regarding optical signals. a. Optical signals are immune from radio frequency interference (RFI) b. Optical signal operate in the THz frequency range, which can support high data throughput c. Optical signals cannot be collected using RF antennas. d. All are correct statements

d. All are correct statements

Which OSI Reference Model layer provides information regarding the proper application port that received data should be sent to? a. Physical Layer 1 b. Data Link Layer 2 c. Network Layer 3 d. Transport Layer 4

d. Transport Layer 4

Select the best definition of a virtual connection or path. a. a virtual connection is one where the signal only travels through an unguided medium b. a virtual connection is one in which a physical path is shared between two users in a half- duplex manner (e.g., push-to-talk radios) c. a virtual connection is another term for a physical connection d. a virtual connection is one in which the physical path is shared by several users, but without their knowledge that the physical path is being shared

d. a virtual connection is one in which the physical path is shared by several users, but without their knowledge that the physical path is being shared

Select the correct statement(s) regarding electrical and electromagnetic (EM) information/signal waves. a. an electrical signal travelling through a guided conductive wire will create a surrounding EM wave that is proportional to the current b. electrical and EM signals carrying information will have an associated bandwidth that can be seen in the frequency domain c. an EM wave in the RF part of the spectrum will create a current in a receive antenna that is proportional to the RF wave d. all are correct statements

d. all are correct statements

For guided mediums, insertion loss is dependent upon which of the following? a. number of connectors and splices b. wire diameter c. signal frequency d. all of the above

d. all of the above

Identify the ways a full duplex digital connection can be achieved between users. a. by separating transmit and receive directions using separate wires, cables, or channels in each direction b. by using different modulation frequencies to separate transmit and receive directions c. by using different time slots to separate transmit and receive frequencies over a common medium d. all of the above

d. all of the above

Select the correct statement(s) regarding partial mesh networks. a. the number of links connecting nodes in a partial mesh network depends upon the availability and reliability requirements of the network b. switches play an integral role in a partial mesh network, where several paths through the network are available c. redundant links and switches are used to improve the availability and reliability of partial mesh networks d. all of the statements are correct

d. all of the statements are correct

Select the correct statement(s) regarding AC signals. a. both current and voltage change over time b. AC can be represented as either a periodic or aperiodic wave c. in a sinusoidal circuit, voltage may be out-of-phase from the current waveform d. all statement are correct

d. all statement are correct

Select the correct statement(s) regarding 4B5B. a. a four bit dataword is mapped to a 5 bit codeword; this results in only half of the possible codewords being mapped to legitimate datawords b. 4B5B means that only 80% of the codeword represents information, with 20% representing overhead c. 4B5B avoids long string of logical "1s" and "0s", thus enabling use of simpler line coding techniques d. all statements are correct

d. all statements are correct

Select the correct statement(s) regarding DC circuits. a. Ohm's law states that voltage equals current multiplied by resistance b. power equals energy expended over time c. power in watts equals voltage multiplied by current d. all statements are correct

d. all statements are correct

Select the correct statement(s) regarding digital baseband modulation. a. with digital modulation, logical "1s" and "0s" are encoded to specific values of carrier wave amplitudes, frequencies, or phase angles b. QAM is a modulation technique in which both carrier amplitude and phase angle changes represent logical data c. with QAM, two carrier waves of the same frequency, but separated by π/2 radians, are used to represent logical data d. all statements are correct

d. all statements are correct

Select the correct statement(s) regarding packet switching networks. a. all packets must contain source and destination addresses in a connectionless packet switching network b. connection-oriented packet switching requires the establishment of a circuit between communicating nodes prior to the exchange of information c. connection-oriented packet switching requires greater use of overhead bits compared to connectionless data exchanges d. all statements are correct

d. all statements are correct

Select the correct statement(s) regarding spread spectrum technologies. a. both direct sequence spread spectrum (DSSS) and frequency hopping spread spectrum (FHSS) results in the signal being spread over a wider frequency bandwidth b. both direct sequence spread spectrum (DSSS) and frequency hopping spread spectrum (FHSS) requires a pseudorandom noise (PN) code and pseudorandom hop sequence, respectively, to be shared between transmitter and receiver c. the transmit power requirements using DSSS and FHSS are the same as a narrow band transmission, even though DSSS and FHSS spreads the signal across a wider frequency spectrum d. all statements are correct

d. all statements are correct

Select the correct statement(s) regarding the signal-to-noise ratio (SNR). a. SNR represents the ratio of receive power to noise floor power b. the decibel form of SNR is a unitless c. the correct equation for SNR in decibels is [SNR]dB = 10 log10(S/N) d. all statements are correct

d. all statements are correct

UTP wire pairs use balanced signaling to eliminate undesired noise components. Select the correct statement(s). a. signals propagate on both wires but appear as mirror images of each other b. balanced signals implement noise canceling techniques c. the twisting of wire pairs minimizes crosstalk d. all statements are correct

d. all statements are correct

Given the following FM modulated signal equation, determine the original message equation, m(t). s(t)= 1cos(2π2.4GHz*t + 5sin(2π7kHz*t)), Kvco=4500 (Hz/v) a. m(t)= 1.8cos(2π2.4E9t) b. m(t)= 1.8cos(2π22E3t) c. m(t)= 14.7cos(2π7kHz*t) d. m(t)= 7.78cos(2π7kHz*t)

d. m(t)= 7.78cos(2π7kHz*t)

Given the following message, m(t), carrier, c(t), and Kvco=5000(Hz/v), determine the FM modulated signal equation and FM index. m(t)=2.3cos(2π3500t), c(t)=5cos(2π4GHzt). a. s(t)=4.5cos(2π4E6t + 3sin(2π3500t)), β=3 b. s(t)=4.5cos(2π3500t + 3.5sin(2π4E6t)), β=3.5 c. s(t)=3cos(2π3500t + 4sin(2π4000t)), β=4 d. s(t)=5cos(2π4E9t + 3.28sin(2π3500t)), β=3.28

d. s(t)=5cos(2π4E9t + 3.28sin(2π3500t)), β=3.28