1.Communication is a process of a)
transfer of information
b)
transfer of energy
c)
transfer of channel
d)
none of these
Ans:a 2.
An example of communication service
a)
printer
b)
television
c)
both(a)&(b)
d)
none of these
Ans:b . Channel is a)
medium
b)
signal
c)
carrier
d)
none of these
Ans:a !. Analog signal varies varies "ith a)
sampling time
b)
time continuously
c)
sampling fre#uency
d)
none of these
Ans:b $. %iscrete signal is represented represented by a)
coding
b)
modulation
c)
demodulation
d)
se#uence of samples
Ans:d . Carrier signal has a)
constant magnitude
b)
constant fre#uency
c)
variable fre#uency
d)
variable time
Ans:a '.odulating signal has a)
lo" fre#uency
b)
lo" modulation
c)
high fre#uency
d)
none of these
Ans:a . odulation index is a)
*m+*c
b)
*c+*m
c)
*m+,c
d)
-one of these
Ans:a .
fc /fm is
a)
upper band fre#uency
b)
lo"er band fre#uency
c)
mid band fre#uency
b)
modulation
c)
demodulation
d)
se#uence of samples
Ans:d . Carrier signal has a)
constant magnitude
b)
constant fre#uency
c)
variable fre#uency
d)
variable time
Ans:a '.odulating signal has a)
lo" fre#uency
b)
lo" modulation
c)
high fre#uency
d)
none of these
Ans:a . odulation index is a)
*m+*c
b)
*c+*m
c)
*m+,c
d)
-one of these
Ans:a .
fc /fm is
a)
upper band fre#uency
b)
lo"er band fre#uency
c)
mid band fre#uency
d)
none of these
Ans:a 10. fc fm is a)
upper band fre#uency
b)
lo"er band fre#uency
c)
mid band fre#uency
d)
none of these
Ans:b 11.,n amplitude modulation fre#uency is a)
constant
b)
3ero
c)
variable
d)
one
Ans:a 12. ,n amplitude modulation amplitude is a)
constant
b)
3ero
c)
variable
d)
none of these
Ans:c 1.,n fre#uency modulation fre#uency is a. constant b. 3ero c. variable d.one Ans:c
1!. ,n fre#uency modulation amplitude is a.constant b.3ero c.one d.variable Ans:a 1$. fre#uency modulation has a)
one carrier
b)
one carrier "ith t"o side band fre#uencies
c)
one carrier "ith in4nite fre#uencies
d)
none of these
Ans:c 1.
Amplitude modulation has
a)
one carrier
b)
one carrier "ith t"o side band fre#uencies
c)
one carrier "ith in4nite fre#uencies
d)
none of these
Ans:b 1'.5 signal is less a6ected by a)
loss
b)
temperature
c)
fre#uency
d)
noise
Ans:d 1. 578 is a)
fre#uency shift 9eying
b)
fre#uency shine 9eying
c)
fre#uency shine 9eyboard
d)
none of these
Ans:a 1. A78 is a)
Amplitude shift 9eying
b)
Amplitude shift 9eyboard
c)
Amplitude shine 9eying
d)
none of these
e)
Ans:a
20. ;A is a)
high po"er audio
b)
high port audio
c)
high po"er ampli4er
d)
none of these
Ans:c 21. ? is used in in a)
telecost
b)
telephone
c)
radio
d)
@*
Ans:d 22. @he fre#uency range of 1> to 0> are referred as a)
sound "aves
b)
micro "aves
c)
mini "aves
d)
none of these
Ans:b 2 . ,5 is a)
interference fre#uency
b)
interconnection fre#uency
c)
intermediate fre#uency
d)
none of these
Ans:c 2!. Bo" pass 4lter attenuates a)
high fre#uencies
b)
lo" fre#uencies
c)
medium fre#uencies
d)
none of these
Ans:a 2$ . high pass 4lter attenuates a)
high fre#uencies
b)
lo" fre#uencies
c)
medium fre#uencies
d)
none of these
Ans:b 2. Bo" pass 4lter allo"s a)
high fre#uencies
b)
medium fre#uencies
c)
3ero fre#uency
d)
lo" fre#uencies
Ans:d
2'. igh pass 4lter allo"s a)
high fre#uencies
b)
medium fre#uencies
c)
3ero fre#uency
d)
lo" fre#uencies
Ans:a 2. ;rimary component of uplin9 section of satellite is a)
transformer
b)
transistor
c)
earth station transmitter
d)
po"er station transmitter
Ans:c 2. icro "ave communication is used in a)
@-D
b)
telephone net"or9s
c)
industries
d)
none of these
Ans:b 0. -on electric signal is converted into electrical signal by a)
transmitter
b)
receiver
c)
line
d)
none of these
Ans:a 1. ,n order to reduce interference the signal should be a)
ampli4ed
b)
multiplied
c)
demodulated
d)
modulated
Ans:d 2. An example for an analog signal a)
7ine "ave
b)
impulse signal
c)
sample signal
d)
-one of these
Ans:a . essages travel from transmitter to receiver "ith help of a)
@ransmitter
b)
Eeceiver
c)
channel
d)
antennas
Ans:c !. Dand"idth of 5 signal is Fthan A signal a)
lesser
b)
either lesser or larger
c)
larger
d)
none of these
Ans:c $. ,n A modulation "hen the modulation index increases transmitted a)
constant
b)
increased
c)
decreased
po"er is
d)
none of these
Ans:b . ,n 5 modulation "hen the modulation index increases transmitted a)
constant
b)
increased
c)
decreased
d)
none of these
Ans:a '. 7ound signalsin @* are a)
amplitude modulated
b)
dc modulated
c)
fre#uency modulated
d)
a and c
Ans:c . *ideo signals in @* are a)
amplitude modulated
b)
de modulated
c)
fre#uency modulated
d)
none of these
Ans:a . ,n optical communication carrier is a)
electromagnetic "aves in optical fre#uency
b)
electromagnetic "aves in maximum fre#uency
c)
electromagnetic "aves in minimum fre#uency
d)
none of these
Ans:a
po"er is
!0. Gptical detector is a)
diode
b)
;,- photo diode
c)
transistor
d)
none of these
Ans:b !1.Gptical 4bre hasFdiameter a.small b.large c.3ero d.none of these Ans:a !2. Gptical 4bre is fabricated by a)
glass
b)
copper
c)
aluminium
d)
none of these
Ans:a !.An earth station receiver consists of a.E5 to ,5 do"n converter b. ,5to E5 converter c.either (a)&(b) d.none of these Ans:a !!. An earth station transmitter consists of a.E5 to ,5 do"n converter
b. ,5to E5 converter c. either (a)&(b) d.none of these Ans:b !$.*5 is a.very lo" fre#uency b.very high fre#uency c.very hot fre#uency d.none of these Ans:b !. @E5 is nothing but a.@* radio fre#uency b.@uned radio fre#uency c.@ube radio fre#uency d.none of these Ans:b !'."hich one of the follo"ing is the type of =superheterodyning? a.Eadio transmitter b.@* c.radio receiver d.radar Ans:c !.A5C is nothing but a.Audio fre#uency control b.Automatic fre#uency control c.Amplitude fre#uency control
d.none of these Ans:b !.@he maximum po"er in A"hen modulation index is a.0 b.0.$ c.0.' d.1 Ans:d $0.;rimary colours are a.redblue.green b.green"hite.blue c.bluered.yello" d.none of these Ans:a
Signals & Systems Questions and Answers – Discrete Time Signals This set of Signals & Systems Multiple Choice Questions & Answers (MCQs) focuses on Discrete Time Signals!" #" $s the function y%n ' sin(%n) periodic or not a) *eriodic +) Aperiodic ,iew Answer Answer- + .planation- /y0 will +e periodic only if attains the same 1alue after some time2 T" 3owe1er2 if is a one4one discrete function2 it may not +e possi+le for some %n"
5" 6hat is the time period of the function %n ' ep(7wn) a) pi85w +) pi8w c) 5pi8w d) 9pi8w ,iew Answer Answer- c .planation- :sing .uler0s rule2 ep(5pi;n) ' # for all integer n" Thus2 the answer can +e deri1ed"
<" 6hat is the nature of the following function- y%n ' y%n4# = %n a) $ntegrator +) Differentiator c) Su+tractor d) Accumulator ,iew Answer Answer- d .planation- $f the a+o1e recursi1e definition is repeated for all n2 starting from #25"" then y%n will +e the sum of all %n ranging from # to n2 ma>ing it an accumulator system"
9" $s the a+o1e function defined2 causal in nature a) Causal +) ?on Causal ,iew Answer Answer- a .planation- As the 1alue of the function depends solely on the 1alue of the input at a time presently and8or in the past2 it is a causal system"
@" $s the function y%n ' %n4# – %n49 memoryless a) The system doesn0t need to ha1e memory +) The system needs to ha1e memory ,iew Answer Answer- + .planation- Since the function needs to store what it was at a time 9 units and # unit +efore the present time2 it needs memory"
" $s the function y%n ' %n4# – %n4@ causal a) The system is non causal +) The system is causal ,iew Answer
Answer- + .planation- As the 1alue of the function depends solely on the 1alue of the input at a time presently and8or in the past2 it is a causal system"
B" $s the function y%n ' y%n4# = %n sta+le in nature a) $t is sta+le +) $t is unsta+le ,iew Answer Answer- a .planation- $t is $ sta+le in nature2 i"e" +ounded input4+ounded output sta+le"
E" $f n tends to infinity2 is the accumulator function a sta+le one a) The function is marginally sta+le +) The function is sta+le c) The function is unsta+le ,iew Answer Answer- c .planation- The system would +e unsta+le2 as the output will grow out of +ound at the maimally worst possi+le case"
F" 6e define y%n ' n%n – (n4#)%n" ?ow2 G%n ' G%n4# = y%n2 is G%n sta+le a) Hes +) ?o ,iew Answer Answer- a .planation- As we ta>e the sum of y%n2 terms cancel out and deem G%n to +e $ sta+le"
#I" 6e define y%n ' n%n – (n4#)%n" ?ow2 G%n ' G%n4# = y%n" $s G%n a causal system a) ?o +) Hes ,iew Answer Answer- + .planation- As the 1alue of the function depends solely on the 1alue of the input at a time presently and8or in the past2 it is a causal system"
A78 ;78 578 and HA are examples of IIIIIIIII encoding. •
a. %igitalJtoJdigital
•
b. %igitalJtoJanalog
•
c. AnalogJto analog
•
d. AnalogJtoJdigital
2. Knipolar bipolar and polar encoding are types of IIIIIIIIIII encoding. •
a. %igitalJtoJdigital
•
b. %igitalJtoJanalog
•
c. AnalogJtoJanalog
•
d. AnalogJtoJdigital
. ;C is an example of IIIIIIIIII encoding. •
a. %igitalJtoJdigital
•
b. %igitalJtoJanalog
•
c. AnalogJto analog
•
d. AnalogJtoJdigital
!. A and 5 are examples of IIIIIIII encoding. •
a. %igitalJtoJdigital
•
b. %igitalJtoJanalog
•
c. AnalogJto analog
•
d. AnalogJtoJdigital
$. ,n HA both phase and IIIIIIII of a carrier fre#uency are varied. •
a. Amplitude
•
b. 5re#uency
•
c. Dit rate
•
d. Daud rate
.
a. ;78
•
b. A78
•
c. 578
•
d. HA
'. ,f the fre#uency spectrum of a signal has a band"idth of $00 3 "ith the highest fre#uency at 00 3 "hat should be the sampling rate according to the -y#uist theoremL •
a. 200 samples+sec
•
b. $00 samples+sec
•
c. 1000 samples+sec
•
d. 1200 samples+sec
. ,f the baud rate is !00 for a !J;78 the bit rate is IIIIII bps. •
a. 100
•
b. !00
•
c. 00
•
d. 100
. %etermine the channel capacity of a ! 93 channel "ith 7+- M 10 dD. •
a. .02 9bps
•
b. !.1' 9bps
•
c. 1.'! 9bps
•
d. 2.$ 9bps
10. ,f the bit rate for an A78 signal is 1200 bps the baud rate is •
a. 00
•
b. !00
•
c. 00
•
d. 1200
11.
a. -EJ,
•
b. E
•
c. anchester
•
d. A,
12. ,f the maximum value of a ;C signal is 1 and the minimum value is J1 ho" many bits "ere used for codingL •
a. !
•
b. $
•
c.
•
d. '
1. %eliberate violations of alternate mar9 inversion are used in "hich type of digitalJtoJdigital encodingL •
a. A,
•
b. D7
•
c. E
•
d. anchester
1!. E encoding involves IIIIIII levels of signal amplitude. •
a. 1
•
b.
•
c. !
•
d. $
1$. ,f the transmission rate of a digital communication system of 10 bps modulation scheme used in 1JHA determined the band"idth eNciency. •
a. 1 bits+cycle
•
b. ! bits+cycle
•
c. bits+cycle
•
d. 2 bits+cycle
1. ,n IIIIIIIII transmission bits are transmitted simultaneously each across its o"n channel . •
a. Asynchronous serial
•
b. 7ynchronous serial
•
c. ;arallel
•
d. A and D
1'. %ata are sent over pin IIIIIIII of the ,AJE7J22 interface. •
a. 2
•
b.
•
c. !
•
d. All of the above
1. ,n the ,AJE7J22 standard "hat does J12* on a data pin representL •
a. 1
•
b. 0
•
c. Knde4ned
•
d. ither 1 or 0 depending on the coding scheme
1. @he maOority of the pins f the ,AJE7J22 interface are used for IIIII purpose. •
a. Control
•
b. @iming
•
c. %ata
•
d. @esting
20. PJ21 uses a IIIII connector. •
a. %DJ1$
•
b. %DJ2$
•
c. %D'
•
d. %DJ
21. ,f you have t"o close compatible %@s that can communicate data that do not need to be modulated. A good interface "ould be IIIIIIII. •
a. A null modem
•
b. An ,AJE7J22 modem
•
c. A %DJ!$ connector
•
d. A transceiver
22.
a. @o narro" band"idth
•
b. @o simplify encoding
•
c. @o increase data rate
•
d. @o reduce the error rate
2. ,n trellis coding. @he number of the data bits is IIIII the number of transmitted bits. •
a. #ual to
•
b. Bess than
•
c. ore than
•
d. %ouble that of
2!.
a. *.
•
b. *.!
•
c. *.
•
d. *.'
2$. @he signal bet"een t"o modems is al"ays
•
a. %igital
•
b. Analog
•
c. ;78
•
d. HA
2. 5or digital communications determine the signal to noise ratio in dD "hich "ould be re#uired for an ideal channel "ith a band"idth of 2$00 3. •
a. $
•
b. .$! dD
•
c. !.'' dD
•
d. .!
2'. 5or a ;C system "ith a maximum decoded voltage at the receiver of Q2.$$ * and minimum dynamic range of ! dD determine the maximum #uanti3ation error. •
a. $.0 *
•
b. 0.$ *
•
c. 0.00$ *
•
d. 0.0$ *
2. %etermine the band"idth eNciency for H;78 modulation scheme at a transmission rate of 10 bps. •
a. 2 bits+cycle
•
b. ! bits+cycle
•
c. bits+cycle
•
d. 1 bits+cycle
2. A modulator converts a (an) IIIIII signal to a (an) IIIIIIIIII signal. •
a. %igital analog
•
b. Analog digital
•
c. ;78 578
•
d. 578 ;78
0.
a. 1JHA
•
b. 578
•
c. J;78
•
d. All of the above
1. A broadcast @* channel has a band"idth of 3. ,gnoring noise calculate the maximum data rate that could be carried in a @* channel using a 1Jlevel code and determine the minimum possible signalJtoJnoise ratio in dD for the calculated data rate. •
a. 2! bps ! dD
•
b. ! bps 2! dD
•
c. 2! bps 2! dD
•
d. ! bps ! dD
2.
a. Dell 10
•
b. Dell 201
•
c. Dell 212
•
d. All of the above
. A maximum length of $0 feet is speci4ed in standard IIIIIIIIII. •
a. ,AJE7J!!
•
b. ,AJE7J22
•
c. ,AJE7J!2
•
d. E7J!22
!. A cable range of !0 to IIIII feet is possible according to the ,AJE7J !! standard.
•
a. $0
•
b. !00
•
c. $00
•
d. !000
$.
a. 10'.$ 93
•
b. .$' 3
•
c. $'.1! 93
•
d. 1.0'$ 3
. @he maximum data rate for E7J!!2 is IIIIIIII times that of the maximum E7J!2 data rate. •
a. 0.1
•
b. 10
•
c. 100
•
d. $00
'. 5or an thernet bus that is $00 meters in length using a cable "ith a velocity factor of 0. and a communication rate of 10 b+s calculate the total number of bits that "ould be sent by each station before it detects a collision if both stations begin to transmit at the same time. •
a. 2$ bits
•
b. 0 bits
•
c. 1 bits
•
d. !1 bits
. A IIIIII is a device that is a source of or a destination for binary digital data. •
a. %ata terminal e#uipment
•
b. %ata transmission e#uipment
•
c. %igital terminal encoder
•
d. %ataJcircuit terminating e#uipment
. An asynchronous communications system uses A7C,, at 00 bps "ith eight bits one start bit one stop bit and no parity bit. xpress the data rate in "ords per minute. (Assume a "ord has 4ve characters and one space). •
a. 00 "pm
•
b. $'00 "pm
•
c. 10 "pm
•
d. 11$20 "pm
!0. A telephone line has a band"idth of .2 93 and a signalJtoJnoise ratio of ! dD. A signal is transmitted do"n this line using a fourJlevel code.
a. 12. 9bps
•
b. .! 9bps
•
c. .1!! 9bps
•
d. 1.0'2 9bps
!1. 5or a binary phase shift 9eying (D;78) modulation "ith a carrier fre#uency of 0 3 and an input bit rate of 10 bps. %etermine the minimum -y#uist band"idth. •
a. !0 3
•
b. 10 3
•
c. 20 3
•
d. $0 3
!2. @he ,A standard speci4ed in the ,AJ22 standard is IIIIII volts. •
a. >reater than J1$
•
b. Bess than J1$
•
c. Det"een J and J1$
•
d. Det"een and 1$
!. 5or a #uaternary phase shift 9eying (H;78) modulation data "ith a carrier fre#uency of '0 3 and input bit rate of 10 bps determine the minimum -y#uist band"idth. •
a. 10 3
•
b. $ 3
•
c. 20 3
•
d. !0 3
!!. 12 voice channels are sampled at 000 sampling rate and encoded into Jbit ;C "ord. %etermine the rate of the data stream. •
a. ' 9bps
•
b. 12 9bps
•
c. 12. 9bps
•
d. !.0 9bps
!$. @he encoding method speci4ed in the ,AJ22 standard is IIIIIIIII. •
a. -EJ,
•
b. -EJB
•
c. anchester
•
d. %i6erential anchester
!. A binary digital signal is to be transmitted at 10 8bits+s "hat absolute minimum band"idth is re#uired to pass the fastest information change undistortedL •
a. $ 93
•
b. 10 93
•
c. 20 93
•
d. 2.$ 93
!'. A coherent binary phase shift 9eyed (D;78) transmitter operates at a bit rate of bps "ith a carrier to noise ratio C+- of . dD. 5ind b+-o.
•
a. . dD
•
b. 1.1 dD
•
c. 21.1 dD
•
d. 1. dD
!. @he ,AJE7J22 interface has IIIIIII pins. •
a. 20
•
b.
•
c. 2$
•
d. 1
!. @he ,AJE7J22 standard de4nes IIIIIIIII characteristics of the %@J%C interface. •
a. echanical
•
b. lectrical
•
c. 5unction
•
d. All of the above
$0. 5or sample rate of 0 93 in a ;C system determine the maximum analog input fre#uency . •
a. 0 93
•
b. 1$ 93
•
c. 0 93
•
d. !$ 93.
@"oJstate (binary) communications systems are better because •
a. @hey can interface directly "ith the analog telephone net"or9
•
b. @he components are simpler less costly and more reliable
•
c. ;eople thin9 better in binary
•
d. ,nterstate calls are less costly
$2. Codes are al"ays •
a. ight bits per character
•
b. ither seven or eight bits per character
•
c. Agreed upon in advance bet"een sender receiver
•
d. @he same in all modern computers
$. %C and %@ •
a. eans Rdigital communications e#uipmentS and Rdigital termination e#uipmentS
•
b. Are connected by either t"o or four "ires
•
c. Eefer to the modem and the computer or terminal respectively
•
d. Any one of the above
$!. @he correctness and the accuracy of the transmitted message content is •
•
a. *eri4ed by the modem b. %etermined by the sender and receiver not by the communications system
•
c. nsured by use of digital techni#ues
•
d. -one of the above
$$. 7erial printers •
a. Are used to transmit grain prices
•
b. Are faster than CE@ terminals and o6er more Texibility
•
c. ;rint one character at a time
•
d. Ksually use serial interfaces
$. rgonomics •
a. ,nvolves the interface bet"een people and machines such as terminals
•
•
•
b. ,s the application of ergoJeconomics to communications c. Ktili3es threeJlevel ergoJcoding for transmission over certain channels d. All of the above
$'. 7erial and parallel transmission •
a. %i6er in ho" many bits are transferred per character
•
b. Are used in synchronous and asynchronous systems respectively
•
c. Doth a and b
•
d. %i6er in "hether the bits are on separate "ires or on one
$. Asynchronous transmission •
a. ,s less eNcient than synchronous but simpler
•
b. ,s much faster than synchronous transmission
•
c. ,s another name for isochronous transmission
$. @he amount of uncertainty in a system of symbols is also called •
a. Dand"idth
•
b. Boss
•
c. ntropy
•
d. Huantum
0. Eedundancy measures •
a. @ransmission rate of a system
•
b. o" li9ely symbols are to be repeated
•
c. @ime bet"een failures
•
d. 7ystem cost
1. Boading refers to the addition of •
a. Eesistors
•
b. Capacitors
•
c. Dullets
•
d. ,nductance
2. @ransmission of binary signals re#uires •
a. Bess band"idth than analog
•
b. ore band"idth than analog
•
c. @he same band"idth as analog
•
d. Cannot be compared "ith the transmission of analog signals
. E7J22 E7J!! E7J$0 *.2! and P.21 are examples of •
a. 7tandard for various types of transmission channels
•
b. 7tandard for interfaces bet"een terminal and modems
•
c. 7tandards for bet"een modems and transmission facilities
•
d. 7tandards for endJtoJend performance of data communications system
!.
a. @he band"idth re#uired is di6erent
•
b. @he pulse heights are di6erent
•
c. @he cloc9ing is mixed "ith the data in asynchronous
•
d. @he cloc9ing is derived from the data in synchronous transmission
$. 7ynchronous modems cost more than asynchronous modems because •
a. @hey are larger
•
b. @hey must contain cloc9 recovery circuits
•
c. @he production volume is larger
•
d. @hey must operate on a larger band"idth
. @he scrambler in a synchronous modem is in the
•
a. Control section
•
b. Eeceiver section
•
c. @ransmitter section
•
d. @erminal section
'. Dinary codes are sometimes transformed in modems into •
a. exadecimal
•
b. u6man codes
•
c. >ray code
•
d. Complementary codes
. @he digitalJtoJanalog converter in a synchronous modem sends signals to the •
a. odulator
•
b. @ransmission line
•
c. @erminal
•
d. #uali3er
. @he transmission signal coding method for @1 carrier is called •
a. Dinary
•
b. -E
•
c. Dipolar
•
d. anchester
'0. @he receiver e#uali3er in a synchronous modem is called •
a. A compromise e#uali3er
•
b. A statistical e#uali3er
•
c. An adaptive e#uali3er
•
d. An impairment e#uali3er
'1. Communications protocols al"ays have a •
a. 7et of symbols
•
b. 7tart of header
•
c. 7pecial Tag symbol
•
d. DCC
'2. @he Daudot code uses ho" many bits per symbolL •
a.
•
b. '
•
c. $
•
d.
'. o" many messages may be ac9no"ledged on a Di7ync lin9L •
a. 1
•
b. 2
•
c. !
•
d.
'!.
a. DC%,C
•
b. A7C,,
•
c. 7D@
•
d. 5ieldata
'$. Gne primary di6erence bet"een %igital %ata Communications essage ;rotocol (%%C;) and 7ynchronous %ata Bin9 Control (7%BC) is •
a. %%C; does not have a transparent mode
•
b. 7%BC does not use a CEC
•
c. %%C; has a message header
•
d. %%C; does not re#uire special hard"are to 4nd the beginning of a message
'.
a. *oiceband modem
•
b. Bocal area net"or9
•
c. Computer bus
•
d. %igital ;DP
''.
a. *oiceband modem
•
b. Bocal area net"or9
•
c. Computer bus
•
d. %igital ;DP
'.
a. ;arallel transmission
•
b. Knlimited expansion
•
c. Bo" cost access for lo" band"idth channels
•
d. Application independent interfaces
'.
a. Eadio
•
b. Gptical 4bers
•
c. Coaxial cable
•
d. @"isted pair
0.
•
a. Access control
•
b. Addressing
•
c. Automatic retransmission of a message
•
d. ultiple virtual net"or9s
1.
a. Continuous energy
•
b. Continuous cloc9 transmissions
•
c. -o dc component
•
d. -o signal change at a 1 to 0 transition
2.
a. %ata lin9 control
•
b. Applications processing
•
c. 5lo" control
•
d. Eouting
. @he purpose of a preamble in an thernet is •
a. Cloc9 synchroni3ation
•
b. rror chec9ing
•
c. Collision avoidance
•
d. Droadcast
!.
a. Knlimited number of stations
•
b. Knlimited distances
•
c. ultiple time division channels
•
d. ,nJservice expansion
$.
a. Knlimited number of stations
•
b. Knlimited distances
•
c. ultiple time division channels
•
d. ,nJservice expansion
.
a. %igital ;DP
•
b. C7A+C% baseband system
•
c. @o9enJpassing net"or9
•
d. Droadband cable system
'.
a. %igital ;DP
•
b. C7A+C% baseband system
•
c. @o9enJpassing net"or9
•
d. Droadband cable system
.
a. 5re#uency agile modems
•
b. ClosedJcircuit @*
•
c. *oice circuits
•
d. 5iber optics transmission
.
a. Computer port concentration
•
b. !J9bps data circuits
•
c. ighJspeed 4le transfers
•
d. @ransmission up to several thousand feet
0.
a. 7impli4ed control signalling
•
b. Bo"er cost telephones
•
c. 5e"er "ire pairs
•
d. ultiplexed voice and data channels
1. @he electrical state of the control leads in a serial interface is a concern of •
a. @he physical layer protocol
•
b. @he data lin9Jlayer protocol
•
c. @he net"or9Jlayer protocol
•
d. -one of the above
2. @he P.2$ standard speci4es a •
a. @echni#ue for dial access
•
b. @echni#ue for startJstop data
•
c. %ata bit rate
•
d. %@+%C interface
. @he P.2$ standard is •
a. Ee#uired for all pac9et s"itching net"or9s
•
b. A recommendation of the CC,@@
•
c. A complete description of a public data net"or9
•
d. Ksed by all pac9et terminals
!. A protocol is a set of rules governing a time se#uence of events that must ta9e place
•
a. Det"een peers
•
b. Det"een nonpeers
•
c. Across an interface
•
d. -one of the above
$. @he P.2$ standard for pac9et net"or9s is analogous to •
a. ;DP standards for a telephone net"or9
•
b. andset standards for a telephone
•
c. Bocal loop standards for a telephone net"or9
•
d. 7"itching standards for a telephone net"or9
. @he G7, reference model de4nes the functions for seven layers of protocols •
a. ,ncluding the user and communications medium
•
b. -ot including the user or communications medium
•
c. ,ncluding the communications medium but not the user
•
d. ,ncluding the user but not the communications medium
'. @he P.2$ standard covers ho" many G7, layersL •
a. @hree
•
b. 5our
•
c. 7even
•
d. -one
. A data pac9et is a pac9et header together "ith •
a. A net"or9 layer
•
b. An administrative layer
•
c. Kser data
•
d. A pac9et s"itch
