Engineering Homework Help
George Mason University Fundamental Principles of Communications Questions
QUESTION 1
undefined
- Radio Frequency (RF) signals are a subset of the electromagnetic (EM) spectrum. Optical signals are also a subset of the EM spectrum.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 2
undefined
- Select the correct statement(s) regarding the difference between analog and digital signals.
undefined
|
a. analog signals are used more extensively in modern computer systems compared to digital signals |
||
|
b. digital signals are represented by logical and discrete values (i.e., “0” and “1”) and therefore logical bits must be grouped together to represent symbols |
||
|
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 |
undefined
10 points
undefined
QUESTION 3
undefined
- By viewing a signal in the frequency domain you can determine which of the following:
undefined
|
a. the frequency and period of the signal |
||
|
b. the signal’s bandwidth and whether it is a traverse of longitudinal wave |
||
|
c. signal amplitude and occupied signal bandwidth |
||
|
d. signal amplitude and sinusoidal period |
undefined
10 points
undefined
QUESTION 4
undefined
- Which of the following are considered “unguided” mediums?
undefined
|
a. copper wire, optical fiber |
||
|
b. vacuum of space, atmosphere |
||
|
c. conductive wiring, air molecules |
||
|
d. none of the above |
undefined
10 points
undefined
QUESTION 5
undefined
- Determine the signal frequency bandwidth given the following: lowest frequency equals 4 Hz and highest frequency equals 22 kHz.
undefined
undefined
|
a. 4Hz |
||
|
b. 22 kHz |
||
|
c. 24 kHz |
||
|
d. 21,996 Hz |
undefined
10 points
undefined
QUESTION 6
undefined
- Select the correct statement(s) regarding electrical and electromagnetic (EM) information/signal waves.
undefined
|
a. an electrical signal travelling through a guided conductive wire will create a surrounding EM signal wave |
||
|
b. electrical and EM signals carrying information will have an associated bandwidth that can be seen in the frequency domain |
||
|
c. electrical signals consist of moving electrons through conductive medium, while EM wave consist of electrical and magnetic energy fields |
||
|
d. all are correct statements |
undefined
10 points
undefined
QUESTION 7
undefined
- OSI is a seven-layered framework used to help define and organize the responsibilities of protocols used for network communications. It does not specifically identify which standards should be used within each layer.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 8
undefined
- Select the OSI layer responsible for data exchange within a common network (e.g., Ethernet LAN).
undefined
|
a. Physical Layer 1 |
||
|
b. Data Link Layer 2 |
||
|
c. Network Layer 3 |
||
|
d. Transport Layer 4 |
undefined
10 points
undefined
QUESTION 9
undefined
- Select the OSI layer responsible for the mechanical and electrical interfaces between devices in a data network.
undefined
|
a. Physical Layer 1 |
||
|
b. Data Link Layer 2 |
||
|
c. Network Layer 3 |
||
|
d. Transport Layer 4 |
undefined
10 points
undefined
QUESTION 10
undefined
- Select the correct statement regarding the OSI Reference Model.
undefined
|
a. analog signals only occupy the first three layers of the OSI RM |
||
|
b. the Network Layer is responsible for end-to-end connectivity over disparate “common networks” |
||
|
c. the OSI Reference Model identifies and approves the standards that must be used in each layer in order to ensure interoperability |
||
|
d. the OSI Reference Model is identical to TCP/IP |
undefined
10 points
undefined
QUESTION 11
undefined
- Select the correct statement(s) regarding partial mesh networks.
undefined
|
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 |
undefined
10 points
undefined
QUESTION 12
undefined
- Identify the correct statement(s) regarding dedicated circuits.
undefined
|
a. dedicated circuits provide point-to-point 24/7 access between communicating points |
||
|
b. the availability of a dedicated circuit to the subscriber is very high |
||
|
c. dedicated circuits are costly and cannot be easily expanded to include additional nodes |
||
|
d. all statements are correct |
undefined
10 points
undefined
QUESTION 13
undefined
- 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.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 14
undefined
- A virtual circuit enables the sharing of physical links by numerous users. Time division multiplexing (TDM) and packet switching techniques are ways in which virtual circuit can be created.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 15
undefined
- Select the correct statement(s) regarding connectionless and connection-oriented networks.
undefined
|
a. packet networks support either connection-oriented or connectionless circuits |
||
|
b. A connection must be established prior to exchanging data when using a connectionless circuit |
||
|
c. packets must contain source and destination addresses in a connection-oriented circuit |
||
|
d. all statements are correct |
undefined
10 points
undefined
QUESTION 16
undefined
- Identify the device that combines multiple time slots or frequency channels into an aggregate for transmission.
undefined
|
a. multiplexer |
||
|
b. modem |
||
|
c. repeater |
||
|
d. switch |
undefined
10 points
undefined
QUESTION 17
undefined
- Two-way PTT (Push-To-Talk) radio is an example of:
undefined
|
a. Simplex Communications |
||
|
b. Half Duplex Communications |
||
|
c. Full Duplex Communications |
||
|
d. Complex Communications |
undefined
10 points
undefined
QUESTION 18
undefined
- A telephone is an example of:
undefined
|
a. Simplex Communications |
||
|
b. Half Duplex Communications |
||
|
c. Full Duplex Communications |
||
|
d. Complex Communications |
undefined
10 points
undefined
QUESTION 19
undefined
- Either acoustic or electromagnetic signals can be used to communicate to satellites in the vacuum of space.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 20
undefined
- Given a wavelength of λ=1000 meters, determine the frequency and signal time period.
undefined
|
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 seconds |
undefined
10 points
undefined
QUESTION 21
undefined
- 1000 MHz (1000E6) is equivalent to:
undefined
|
a. 1000kHz |
||
|
b. 10GHz |
||
|
c. 1GHz |
||
|
d. 1THz |
undefined
10 points
undefined
QUESTION 22
undefined
- Given the following parameters, determine the correct sinusoidal equation for a sine wave: f=1kHz, A=5v, φ (phase angle)=+π radians.
undefined
|
a. 1sin(2π5t – π) |
||
|
b. 5sin(2π1000t) |
||
|
c. 5sin(2π1000t + π) |
||
|
d. 5sin(2π1t + π) |
undefined
10 points
undefined
QUESTION 23
undefined
- Identify the correct equation that describe the relationship between a sine and cosine wave.
undefined
|
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) |
undefined
10 points
undefined
QUESTION 24
undefined
- 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.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 25
undefined
- What is correct regarding an ideal isotropic antenna?
undefined
|
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 |
undefined
10 points
undefined
QUESTION 26
undefined
- Select the correct statement regarding modulation/demodulation.
undefined
|
a. the passband signal is combined with the carrier wave to produce a baseband which operates at a higher frequency |
||
|
b. the carrier signal is combined with the passband wave to produce a baseband which operates at a higher frequency |
||
|
c. the passband signal is combined with the baseband wave to produce a carrier which operates at a higher frequency |
||
|
d. the baseband signal is combined with the carrier wave to produce a passband which operates at a higher frequency |
undefined
10 points
undefined
QUESTION 27
undefined
- Select the correct statement(s) regarding optical signals.
undefined
|
a. Optical signals are susceptible to radio frequency interference (RFI) |
||
|
b. Although optical signals are part of the electromagnetic spectrum, they have different properties/characteristics and operate at higher frequencies than RF signals |
||
|
c. Although optical signals are in the THz range, an RF antenna tuned to the proper frequency can collect an optical signal |
||
|
d. All are correct statements |
undefined
10 points
undefined
QUESTION 28
undefined
- Convert 120E3 mW to dBm
undefined
|
a. 30 dBm |
||
|
b. 20.8 dBm |
||
|
c. 50.8 dBm |
||
|
d. 80.8 dBm |
undefined
10 points
undefined
QUESTION 29
undefined
- Convert 300 watts to dBm
undefined
|
a. 54.77 dBm |
||
|
b. 24.77 dBm |
||
|
c. 300 dBm |
||
|
d. 24.77 dBW |
undefined
10 points
undefined
QUESTION 30
undefined
- Convert 765 watts to dBm
undefined
|
a. 58.84 dBm |
||
|
b. 28.84 dBm |
||
|
c. 300 dBm |
||
|
d. 24.77 dBW |
QUESTION 1
undefined
- Radio Frequency (RF) signals are a subset of the electromagnetic (EM) spectrum. Optical signals are also a subset of the EM spectrum.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 2
undefined
- Select the correct statement(s) regarding the difference between analog and digital signals.
undefined
|
a. analog signals are used more extensively in modern computer systems compared to digital signals |
||
|
b. digital signals are represented by logical and discrete values (i.e., “0” and “1”) and therefore logical bits must be grouped together to represent symbols |
||
|
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 |
undefined
10 points
undefined
QUESTION 3
undefined
- By viewing a signal in the frequency domain you can determine which of the following:
undefined
|
a. the frequency and period of the signal |
||
|
b. the signal’s bandwidth and whether it is a traverse of longitudinal wave |
||
|
c. signal amplitude and occupied signal bandwidth |
||
|
d. signal amplitude and sinusoidal period |
undefined
10 points
undefined
QUESTION 4
undefined
- Which of the following are considered “unguided” mediums?
undefined
|
a. copper wire, optical fiber |
||
|
b. vacuum of space, atmosphere |
||
|
c. conductive wiring, air molecules |
||
|
d. none of the above |
undefined
10 points
undefined
QUESTION 5
undefined
- Determine the signal frequency bandwidth given the following: lowest frequency equals 4 Hz and highest frequency equals 22 kHz.
undefined
undefined
|
a. 4Hz |
||
|
b. 22 kHz |
||
|
c. 24 kHz |
||
|
d. 21,996 Hz |
undefined
10 points
undefined
QUESTION 6
undefined
- Select the correct statement(s) regarding electrical and electromagnetic (EM) information/signal waves.
undefined
|
a. an electrical signal travelling through a guided conductive wire will create a surrounding EM signal wave |
||
|
b. electrical and EM signals carrying information will have an associated bandwidth that can be seen in the frequency domain |
||
|
c. electrical signals consist of moving electrons through conductive medium, while EM wave consist of electrical and magnetic energy fields |
||
|
d. all are correct statements |
undefined
10 points
undefined
QUESTION 7
undefined
- OSI is a seven-layered framework used to help define and organize the responsibilities of protocols used for network communications. It does not specifically identify which standards should be used within each layer.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 8
undefined
- Select the OSI layer responsible for data exchange within a common network (e.g., Ethernet LAN).
undefined
|
a. Physical Layer 1 |
||
|
b. Data Link Layer 2 |
||
|
c. Network Layer 3 |
||
|
d. Transport Layer 4 |
undefined
10 points
undefined
QUESTION 9
undefined
- Select the OSI layer responsible for the mechanical and electrical interfaces between devices in a data network.
undefined
|
a. Physical Layer 1 |
||
|
b. Data Link Layer 2 |
||
|
c. Network Layer 3 |
||
|
d. Transport Layer 4 |
undefined
10 points
undefined
QUESTION 10
undefined
- Select the correct statement regarding the OSI Reference Model.
undefined
|
a. analog signals only occupy the first three layers of the OSI RM |
||
|
b. the Network Layer is responsible for end-to-end connectivity over disparate “common networks” |
||
|
c. the OSI Reference Model identifies and approves the standards that must be used in each layer in order to ensure interoperability |
||
|
d. the OSI Reference Model is identical to TCP/IP |
undefined
10 points
undefined
QUESTION 11
undefined
- Select the correct statement(s) regarding partial mesh networks.
undefined
|
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 |
undefined
10 points
undefined
QUESTION 12
undefined
- Identify the correct statement(s) regarding dedicated circuits.
undefined
|
a. dedicated circuits provide point-to-point 24/7 access between communicating points |
||
|
b. the availability of a dedicated circuit to the subscriber is very high |
||
|
c. dedicated circuits are costly and cannot be easily expanded to include additional nodes |
||
|
d. all statements are correct |
undefined
10 points
undefined
QUESTION 13
undefined
- 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.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 14
undefined
- A virtual circuit enables the sharing of physical links by numerous users. Time division multiplexing (TDM) and packet switching techniques are ways in which virtual circuit can be created.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 15
undefined
- Select the correct statement(s) regarding connectionless and connection-oriented networks.
undefined
|
a. packet networks support either connection-oriented or connectionless circuits |
||
|
b. A connection must be established prior to exchanging data when using a connectionless circuit |
||
|
c. packets must contain source and destination addresses in a connection-oriented circuit |
||
|
d. all statements are correct |
undefined
10 points
undefined
QUESTION 16
undefined
- Identify the device that combines multiple time slots or frequency channels into an aggregate for transmission.
undefined
|
a. multiplexer |
||
|
b. modem |
||
|
c. repeater |
||
|
d. switch |
undefined
10 points
undefined
QUESTION 17
undefined
- Two-way PTT (Push-To-Talk) radio is an example of:
undefined
|
a. Simplex Communications |
||
|
b. Half Duplex Communications |
||
|
c. Full Duplex Communications |
||
|
d. Complex Communications |
undefined
10 points
undefined
QUESTION 18
undefined
- A telephone is an example of:
undefined
|
a. Simplex Communications |
||
|
b. Half Duplex Communications |
||
|
c. Full Duplex Communications |
||
|
d. Complex Communications |
undefined
10 points
undefined
QUESTION 19
undefined
- Either acoustic or electromagnetic signals can be used to communicate to satellites in the vacuum of space.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 20
undefined
- Given a wavelength of λ=1000 meters, determine the frequency and signal time period.
undefined
|
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 seconds |
undefined
10 points
undefined
QUESTION 21
undefined
- 1000 MHz (1000E6) is equivalent to:
undefined
|
a. 1000kHz |
||
|
b. 10GHz |
||
|
c. 1GHz |
||
|
d. 1THz |
undefined
10 points
undefined
QUESTION 22
undefined
- Given the following parameters, determine the correct sinusoidal equation for a sine wave: f=1kHz, A=5v, φ (phase angle)=+π radians.
undefined
|
a. 1sin(2π5t – π) |
||
|
b. 5sin(2π1000t) |
||
|
c. 5sin(2π1000t + π) |
||
|
d. 5sin(2π1t + π) |
undefined
10 points
undefined
QUESTION 23
undefined
- Identify the correct equation that describe the relationship between a sine and cosine wave.
undefined
|
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) |
undefined
10 points
undefined
QUESTION 24
undefined
- 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.
undefined
True
undefined
False
undefined
10 points
undefined
QUESTION 25
undefined
- What is correct regarding an ideal isotropic antenna?
undefined
|
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 |
undefined
10 points
undefined
QUESTION 26
undefined
- Select the correct statement regarding modulation/demodulation.
undefined
|
a. the passband signal is combined with the carrier wave to produce a baseband which operates at a higher frequency |
||
|
b. the carrier signal is combined with the passband wave to produce a baseband which operates at a higher frequency |
||
|
c. the passband signal is combined with the baseband wave to produce a carrier which operates at a higher frequency |
||
|
d. the baseband signal is combined with the carrier wave to produce a passband which operates at a higher frequency |
undefined
10 points
undefined
QUESTION 27
undefined
- Select the correct statement(s) regarding optical signals.
undefined
|
a. Optical signals are susceptible to radio frequency interference (RFI) |
||
|
b. Although optical signals are part of the electromagnetic spectrum, they have different properties/characteristics and operate at higher frequencies than RF signals |
||
|
c. Although optical signals are in the THz range, an RF antenna tuned to the proper frequency can collect an optical signal |
||
|
d. All are correct statements |
undefined
10 points
undefined
QUESTION 28
undefined
- Convert 120E3 mW to dBm
undefined
|
a. 30 dBm |
||
|
b. 20.8 dBm |
||
|
c. 50.8 dBm |
||
|
d. 80.8 dBm |
undefined
10 points
undefined
QUESTION 29
undefined
- Convert 300 watts to dBm
undefined
|
a. 54.77 dBm |
||
|
b. 24.77 dBm |
||
|
c. 300 dBm |
||
|
d. 24.77 dBW |
undefined
10 points
undefined
QUESTION 30
undefined
- Convert 765 watts to dBm
undefined
|
a. 58.84 dBm |
||
|
b. 28.84 dBm |
||
|
c. 300 dBm |
||
|
d. 24.77 dBW |
