Chapter 6: Earth Science

25 July 2022
4.7 (114 reviews)
31 test answers

Unlock all answers in this set

Unlock answers (27)
question
White noise is also called thermal noise or ____ noise. a. crosstalk c. Gaussian b. jitter d. spike
answer
c. Gaussian
question
Impulse noise is also known as ____. a. noise spike c. attenuation b. jitter d. crosstalk
answer
a. noise spike
question
Typically, impulse noise is a(n) ____ burst of energy. a. digital c. binary b. analog d. logical
answer
b. analog
question
High humidity and wet weather can cause an increase in electrical ____ over a telephone system. a. compression c. jitter b. attenuation d. crosstalk
answer
d. crosstalk
question
To minimize the effect of echo, a device called a(n) ____ can be attached to a line. a. echo suppressor c. amplifier b. repeater d. hub
answer
a. echo suppressor
question
____ is the result of small timing irregularities that become magnified during the transmission of digital signals as the signals are passed from one device to another. a. White noise c. Attenuation b. Jitter d. Echo
answer
b. Jitter d
question
Causes of jitter can include electromagnetic interference, ____, passing the signal through too many repeaters, and the use of lower-quality equipment. a. coding c. compression b. sampling d. crosstalk
answer
d. crosstalk
question
____ is not necessarily a form of error, but can indirectly lead to an increase in errors affecting the transmitted signal. a. Impulse noise c. Attenuation b. Crosstalk d. White noise
answer
c. Attenuation
question
____ means that if the transmitting modem sends data and the data arrives garbled, the receiving modem may ask the transmitting modem to fall back to a slower transmission speed. a. Impulse negotiation c. Attenuation b. Fallback negotiation d. Downlink
answer
b. Fallback negotiation
question
Twisted pair Category 5e/6 cable should not be longer than the recommended 100-meter (300-foot) distance when it's transmitting at ____ Mbps. a. 100 c. 500 b. 250 d. 1000
answer
a. 100
question
Installing proper shielding on cables prevents ____. a. white noise c. attenuation b. impulse noise d. crosstalk
answer
d. crosstalk
question
Error detection can be performed in several places within a communications model. One of the most common places is the TCP/IP ____ layer. a. network c. network access/data link b. application d. physical
answer
c. network access/data link
question
The most basic error-detection techniques are parity checks, which are used with ____ connections. a. synchronous c. statistical b. asynchronous d. fiber-optic
answer
b. asynchronous
question
With ____ parity, the 0 or 1 added to the string produces an even number of binary 1s. a. even c. longitudinal b. odd d. binary
answer
a. even
question
Isolated single-bit errors occur ____ percent of the time. a. 30 to 40 c. 50 to 60 b. 40 to 50 d. 60 to 70
answer
c. 50 to 60
question
Error bursts occur ____ percent of the time. a. 2 to 5 c. 8 to 10 b. 5 to 10 d. 10 to 20
answer
d. 10 to 20
question
Longitudinal parity is sometimes called longitudinal redundancy check or ____ parity. a. vertical c. random b. horizontal d. binary
answer
b. horizontal
question
The cyclic redundancy checksum (CRC) is also called ____. a. horizontal parity c. bit parity b. vertical cyclic parity d. cyclic checksum
answer
d. cyclic checksum
question
CRC-____ is found in Ethernet LANs. a. 5 c. 32 b. 12 d. 64
answer
c. 32
question
____ for error control is becoming a mode of operation for some modern wide area network transmission techniques. a. Returning a message c. Correcting the error b. Doing nothing d. Fixing the error
answer
b. Doing nothing
question
____ is offered by telephone companies to transfer data over wide areas. a. RS-232 c. SSL b. EIA-232F d. Frame Relay
answer
d. Frame Relay
question
____ cable is the medium least prone to generating errors. a. Fiber-optic c. Twisted-pair b. Coaxial d. Copper-based
answer
a. Fiber-optic
question
____ is probably the most common form of error control. a. Do nothing b. Correct the error without retransmission c. Sending a message back to the transmitter d. Correct the error with retransmission
answer
c. Sending a message back to the transmitter
question
____ error control is a technique usually associated with the Stop-and-wait flow control protocol. a. Stop-and-wait c. Sliding window b. Timeout d. ACK
answer
a. Stop-and-wait
question
When working with stop-and-wait error control, the amount of time a station waits before retransmitting a packet is called ____. a. stop time c. NAK time b. ACK time d. timeout
answer
d. timeout
question
____ is a flow control scheme that allows a station to transmit a number of data packets at one time before receiving some form of acknowledgment. a. Stop-and-wait c. Timeout b. Sliding window d. ACK window
answer
b. Sliding window
question
With the sliding window protocol, a station that had a maximum window size of 7 could transmit only ____ data packets at one time before it had to stop and wait for an acknowledgment. a. 5 c. 7 b. 6 d. 8
answer
c. 7
question
A ____ protocol's function is simply to inform the transmitter what piece of data is expected next. a. CRC-16 c. stop-and-wait b. CRC-32 d. sliding window
answer
d. sliding window
question
For a receiver to be able to fix an errorโ€”in a process called ____โ€”redundant information must be present so that the receiver knows which bit or bits are in error and what their original values were. a. forward error correction c. backward error correction b. forward error detection d. backward error detection
answer
a. forward error correction
question
If a receiver correctly receives packets 2, 3, and 4, it will respond with a(an) ____ . a. ACK 3 c. ACK 5 b. ACK 4 d. NAK
answer
c. ACK 5
question
If a receiver has just received one packet of data with bytes numbered 600 to 700, it will respond immediately with ____. a. an ACK of 700 c. an ACK of 800 b. an ACK of 701 d. it will not respond just yet
answer
b. an ACK of 701