Find the binary equivalent of x8+x3+x+1 5
Find LRC for the following data?
10101010 10010101 11010110 3
What are the common Gigabit Ethernet implementations? [3]
In HDLC, what is bit stuffing? [2]
How can we use the Hamming code to correct a burst error? [2]
How are lost acknowledgment and a lost frame handled at the sender site? [5]
What is geosynchronous satellite? 3
Which modem was first developed commercially in 1970? 2
Explain Fiber Distributed Data Interface (FDDI) architecture of LAN? 10
40
In Fast Ethernet, data rate can be increased by _______________ collisions.
Increasing
Decreasing
Keeping Constant
All of above
39
In Token Ring, Monitor station generates a new token when it is lost
True
False
38
The BNC-T connector is a T-shaped device with _______ ports
three
two
four
five
37
Like 10 Base 5, 10 Base 2 is a _________ topology LAN
Bus
Star
Ring
Mesh
36
The HDLC ___________ field defines the beginning and end of a frame.
Flag
Address
Control
FCS
35
In __________ ARQ, if a NAK is received, only the specific damaged or lost frame is retransmitted.
Stop-and-wait
Go-Back-N
Selective repeat
Stop-and-wait & Go-back-N
34
For a sliding window of size N-1 (N sequence numbers), there can be a maximum of __________ frames sent but unacknowledged.
N-1
N
N+1
0
33
The sum of the checksum and data at the receiver is __________ if there are no errors
The complement of the checksum
The complement of the data
-0
+0
32
If odd parity is used for ASCII error detection, the number of 0s per 8-bit symbol is _________
Indeterminate
42
even
odd
31
At the CRC generator, __________ added to the data unit after the division process
The polynomial
The CRC remainder is
0s are
1s are
30
Which error detection method can detect a single-bit error?
Simple parity check
Two-dimensional parity check
CRC
All of the given
29
Which error detection method involves the use of parity bits?
Simple parity check & two dimensional parity check
CRC
Two-dimensional parity check
Simple parity check
28
Which of the following best describes a single-bit error?
A single bit is inverted
A single bit is inverted per data unit
A single bit is inverted per transmission
27
The local loop has ___________ cable that connects the subscriber telephone to the nearest end office.
Twisted-pair
Coaxial
Fiber-optic
None of the given
26
A telephone network is an example of a __________ network.
Packet-switched
Circuit-switched
Message-switched
none of the given
25
Which multiplexing technique involves signals composed of light beams?
FDM
TDM
WDM
None
24
dB is ____________ if a signal is amplified.
-ive
+ive
Null
Zero
23
dB is ____________ if a signal is attenuated.
Negative
Positive
Null
Zero
22
Middle frequency waves having range 300 KHz-3 MHz always use __________ propagation.
Ground
Sky
Line Of Sight
Space
21
In __________ propagation, low-frequency radio waves hug the earth.
Ground
Sky
Line Of Sight
Space
20
A parabolic dish antenna is a(n) ______________ antenna.
Omnidirectional
Bidirectional
Unidirectional
Horn
19
In ______________ method a signal can be directed in a straight from Antenna to antenna.
Line of sight
Ground propagation
Sky propagation
Microwaves
18
Optical fibers are defined by the ratio of the ___________ of their core to the diameter of their cladding.
Diameter
Radius
Length
Width
17
When we talk about unguided media, usually we are referring to _________.
Metallic wires
Nonmetallic wires
The air
Water
16
When a beam of light travels through media of two different densities, if the angle of incidence is greater than the critical angle, ____________occurs.
Reflection
Refraction
Incidence
Criticism
15
Which of the following primarily uses guided media
Cellular telephone system
Local telephone system
Satellite communications
Radio broadcasting
14
Transmission media are usually categorized as _____________
Fixed or Unfixed
Guided or Unguided
Determinate or Indeterminate
Metallic or Nonmetallic
13
Transmission of data from the subscriber to the ISP is called uploading.
True
False
12
Traditional telephony lines carry frequencies btw 300 Hz and 3300 Hz giving them a bandwidth of 3000 Hz.
3100
3000
3200
3300
11
In RS 422 Balanced mode two lines carry ________ signals which are not identical to each other.
same
different
analog
digital
10
In _____________ transmission, a start bit and a stop bit frame a character byte.
Asynchronous serial
Synchronous serial
Parallel
Asynchronous & Synchronous serial
09
In _____________ transmission, bits are transmitted over a single wire, one at a time.
Asynchronous serial
Synchronous serial
Parallel
Asynchronous & Synchronous serial
8
The bit rate always equals the baud rate in which type of signal?
FSK
QAM
4-PSK
PSK
7
A 56k modem can download at a rate of __________ Kbps and upload at a rate of __________ Kbps.
33.6: 33.6
33.6: 56.6
56.6: 33.6
56.6: 56.6
6
Frequency band in which 99% of the total power resides is called_______
power bandwidth
half power bandwidth
3dB bandwidth
F.M.
5
Unidirectional traffic movement is overcome by dual ring technology.
True
False
4
__________representation of links that connect nodes is called as physical topology.
physical
geometrical
logical
3
Which topology requires a central controller or hub?
Mesh
Star
Bus
Ring
2
Dividing data into manageable parts or data chunks is called as
packetizing
framing
both are true
both are false
1
The information to be communicated in a data communications system is the
Medium
Protocal
Message
Transmission
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