Download - Questions for Est - NS 47
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1. It is the transmission, reception, and
processing of information between two or more
locations using electronic circuits.2.
A. Electronic communicationsB. Electronic transferC. Electronic modeD. Electronic codes
3. he noise produced b! a resistor is to beamplified b! a noiseless amplifier ha"ing a
"oltage gain of #$ and a bandwidth of 1%%
&'(. A sensiti"e meter at the output reads
2)% micro"olts rms. Assuming operation at 3#
degrees, calculate the resistor*s resistance.).
A. ) &ilo ohmsB. $ &ilo ohmsC. + &ilo ohmsD. # &ilo ohms
$. he first electronic communications s!stem
was de"elop in what centur!
+.A. 1#thB. 1-thC. 1thD. 2%thE.
#. /ho was the first to successfull! transmit
wireless radio signals through Earth*s
atmosphere
A. 0amuel orseB. 'oward ArmstrongC. ee DeorestD. 4ugliemo arconiE.
. /ho in"ented fre5uenc! modulation
A. 4ugliemo arconiB. homas /atsonC. Ale6ander 4raham BellD. 'oward Armstrong
-. A component of the electronic communications
s!stem that pro"ides a means of transporting
signals from a transmitter to a recei"er.1%.
A. InformationB. odulatorC. edium
D. ransmitterE.
11. Calculate the noise power outputs of a 1 &ilo
ohm resistor at 2# degrees C o"er a 1%%7&'(
bandwidth.
A. ).1)f/B. %.)1) f/C. 1).1 f/D. 1)1 f/E.
12. 8888888 is a collection of electronic de"ices
and circuits that accepts the transmitted
signals from the transmission medium and
3$-. he simplest and most straightforward f
of telephone ser"ice is called
public switch telephone networ&
mobile telephone switching office
plain and old telephone ser"ice
central office ser"ice
3+%. 888888 are local telephone switches
e5uipped with 00#7compatible software and
terminating signal lin&s
switching points
ser"ice points
point codes
ser"ice switching points
3+1. A 9AB: is normall! connected to the
central office "ia an interface de"ice cal
branch e6change unit
subscriber loop unit
foreign e6change unit
local e6change unit
3+2. he most widel! used fa6 standard is
group 1
group 2
group 3
group )
3+3. he modern ouch7tone telephone is call
+%%7t!pe telephone set
2$%%7t!pe telephone set
2%%7t!pe telephone set
1$%%7t!pe telephone set
3+). 0ignals that pro"ides call status
information, such as bus! or ringbac& sign
ringing
super"ising
h!briding
controlling
3+$. A signal sent bac& to the calling part!
the same time the ringing signal is sent t
the called part!.
bus! signal
ringing signal
ringbac& signal
dial tone
3++. It is comprised of two or more faciliti
interconnected in tandem to pro"ide a
transmission path between a source and a
destination
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con"erts them bac& to their original form.13.
A. ChannelB. ;ecei"erC. ransmitterD. Antenna
1). A signal that carries the information through
the s!stem.1$.
A. Information
B. modulating signalC. intelligenceD. carrier
1+. A signal that modulates a high7fre5uenc!
signal or carrier in order to transfer
information from one location to another.1#.
A. IntelligenceB. modulated signalC. carrierD. intelligence or modulated signalE.
1. ourier series shows that a sawtooth wa"e
consists of the following e6cept
A. fundamental and subharmonic sine wa"esB. a fundamental sine wa"e and an infinite
number of harmonicsC. fundamental and harmonic sine wa"es whose
amplitudeD. decreases with the harmonic numberE. sinusoidal "oltages, some of which are
small enough to ignore. in practice
1-. Determine the noise current for a diode with
a forward bias of 1 mA o"er a 1 '(
bandwidth.
A. 1-. nAB. 1#.- nAC. 12.3 nAD. 1+ nA
2%. he process of changing one or more
properties of the carrier in proportion with
the information signal
A. demodulationB. transmissionC. modulation
D. reception
21. A s!stem where digital pulses are transferred
between two points in a communication s!stem.
A. digital transmissionB. analog transmissionC. digital radioD. analog communications s!stem
22. It is the transmittal of digitall! modulated
analog carriers between two or more points in
a communications s!stem.
telephone line
telephone set
telephone circuit
telephone trun&
3+#. he drum diameter of a facsimile machin
is -%.2 mm and the scanning pitch is %.2 m
per scan. ind the inde6 of cooperation
according to CCI
)$1
2.22 : 1%< 73
1)1#
1))
3+. It is the ratio in dB of the power of a
signal at that point to the power the same
signal would be %7dBm at an! point in the
transmission
data le"el
baseband le"el
"oice le"el
transmission le"el
3+-. It is an indirect method of e"aluating
phase dela! characteristics of the circuit
phase dela! distortion
en"elope dela! distortion
non7linear distortion
linear distortion
3#%. It is characteri(ed b! high7amplitude
pea&s of short duration ha"ing an
appro6imatel! flat fre5uenc! response
crosstal&
interference
impulse noise
dropout
3#1. It is the presence of one or more
continuous, unwanted tones within the mess
channels, the tones are often caused b!
crosstal& or cross modulation between
ad=acent channels in a transmission s!stem
due to s!stem nonlinearities.
multiple7fre5uenc! interference
single7fre5uenc! interference
co7channel interference
desensiti(ing
3#2. hat portion of the local loop that is
strung between the poles
Aerial
distribution cable
feeder cable
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A. analog transmissionB. digital radioC. digital communicationsD. digital reception
23. !pe of modulation where the carrier
amplitude is "aried proportional to the
information signal
A. AB. 9C. D. 9ulse modulation
2). ln , the 888888 is "aried proportional to
the information signal
A. phaseB. timeC. amplitudeD. fre5uenc!
2$. A circuit that performs modulation
A. demodulatorB. s!nthesi(erC. modulatorD. limiter
2+. Calculate the signal to noise ratio for a
recei"er output of ) > signal and %.) >
noise in dB.
A. 1.$ dBB. +- dBC. 2$.) dBD. -.2$ dB
2#. odulation used is to the following e6cept
A. reduce the bandwidth usedB. separate differing transmissionC. ensure that intelligence ma! be
transmitted o"er long distanceD. allow the use of practicable antennas
2. It performs the re"erse process of modulation
and con"ens the modulated carrier bac& to the
original information.
A. oscillatorB. demodulatorC. s!nthesi(erD. mi6er
2-. Indicate the false statement? he reasons wh!
modulation is necessar! in electronic
communications is because?
A. lt is e6tremel! difficult to radiate low7
fre5uenc! signals from antenna in the form
of electromagnetic energ!.B. Information signals often occup! the same
twisted7pair
3#3. It is the primar! cause of attenuation
phase distortion on a telephone circuit
local line
local loop
subscriber loop
an! of these
3#). It is simpl! the fre5uenc! response of
transmission medium referenced to a 1%%)7'
test tone
attenuation distortion
differential gain
1%%)7'( de"iation
an! of these
3#$. he time dela! measured in angular unit
such as degrees or radians is called 88888
propagation time
phase dela!
holding time
s!stem dela! time
3#+. lt is a communications term that indica
the presence of a signal power comparable
the power of an actual message transmissio
d!namic range
loaded
node
reference
3##. It is an! de"ice used to originate and
terminate calls and to transmit and recei"
signals into and out of the telephone netw
instrument
station e5uipment
station
an! of these
3#. E6changes connected directl! to the loc
loops are called 888888.
central office
local e6change
e6change offices
an! of these
3#-. It pro"ides functionalit! of communicat
with the "oice switch b! creating the pac&
or signal units necessar! for transmission
o"er the 00# networ&.
switching points
ser"ice points
point codes
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fre5uenc! band and if signals from two or
more sources at the same time, the! would
interfere with each other.C. o reduce the si(e of the capacitors and
inductors of the tuned circuit.D. o increase the si(e of the transmitting
and recei"ing antenna.
3%. he process of con"erting a fre5uenc! or band
of fre5uencies to another location in thetotal fre5uenc! spectrum is called?
A. ranslationB. demodulationC. modulationD. oscillation
31. An intricate part of electronic
communications s!stem because of its up7and
down7con"ersion functions as the! are
transported through a channel.
A. oscillationB. modulationC. demodulationD. translation
32. 8888888 is simpl! the number of times a
periodic motion occurs in a gi"en unit of
time
A. fre5uenc!B. timeC. periodD. phase
33. he difference between the highest and thelowest fre5uencies contained in the
information
A. noiseB. bandwidthC. interferenceD. fre5uenc!
3). lt is a highl! theoretical stud! of the
efficient use of bandwidth to propagate
information through electronic communications
s!stems
A. information capacit!B. information bandwidthC. information theor!D. information entrop!
3$. It is the measure of how much information can
be transferred through a communications
s!stem in a gi"en period of time
A. information bandwidthB. information capacit!C. information densit!D. information theor!
ser"ice switching points
3%. In a )7wire telephone set connection,
@used to connect telephone set to central
office switching the green coded wire is
used 888888.
as ground wire
to transmit the signal
to recei"e the signal from the far end
as a spare or for special purpose application
31. A techni5ue where the called subscriber
ser"ed b! an! other central office, the
switching e5uipment will ha"e to transfer
digit dialed to the called switching
e5uipment.
loop signaling
step7b!7step switching
interoffice calling
duple6 signaling
32. Electromagnetic coupling between two or
more transmission media is what t!pe of
crosstal&
coupling crosstal&
transmission crosstal&
linear crosstal&
non7linear crosstal&
33. he number or dedicated lines used to
interconnect 1%% parties is
-- lines
12$% lines
)-$% lines
3)$% lines
3). Class of switching office which is the
local e6change where the subscriber loops
terminated and recei"ed dial tone.
Class $
Class )C
Class 3
Class 1
3$. he ma6imum intelligibilit! of "oice
fre5uenc! is between
2%%% and 3%%% '(
1%%% and 3%%% '(
2$%% and )%%% '(
1%%% and 2$%% '(
3+. lt is the state of the telephone when
is idle.
on7hoo&
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3+. he law that states that the wider the
bandwidth and the longer the r time of
transmission, the more information that can
be con"e!ed through the s!stem.
A. Information theor!B. Information densit! lawC. 'artle!s lawD. Information entrop! law
3#. A circuit configuration that in"ol"es one
wire for the signal and one for the reference
or ground.
A. 27wireB. )7wireC. 37wireD. 17wire
3. A circuit configuration that in"ol"es two for
signal and two for reference or ground.
A. 27wireB. )7wireC. 37wireD. 17wire
3-. It is used to match impedances and pro"ide
isolation between the two directions of
signal flow.
A. 27wireB. h!brid setC. )7wire transmissionD. 0uppressors
)%. An interface circuit that is used when a two7wire circuit is connected to a four7wire
circuit, as in long7distance telephone call.
A. suppressorsB. echo limiterC. codecD. terminating set
)1. An amplifier with a noise figure of + dB has
an input signal7to7noise ratio of 2$ dB.
Calculate the output signal7to7noise ratio in
dB.
A. 31 dBB. 1- dBC. 2% dBD. 2$ dB
)2. It is the process of combining two or more
signals and is an essential process in
electronic communications.
A. oscillationB. mi6ingC. dampingD. modulation
off7hoo&
semi7hoo&
hoo&7in
3#. !pe of loop signaling which is widel!
used in new switchlri s!stems to super"ise
trun&s between two central offices.
batter! and ground pulsing
re"erse batter! signaling
loop pulsing
duple6 signaling
3. 9rinted documents to be transmitted b!
are con"erted into a baseband electrical
signal b! the process of
reflection
scanning
modulation
light "ariations
3-. he transmission speed of group ) fa6
)%% baud
-+%% baud
$+ &bps
1-2 &bps
3-%. It is a distortion formed if 00B is use
where the information bandwidth is greater
than half of the carrier fre5uenc!.
near7far effect
hauffman effect
&endall effect
herringbone effect
3-1. lt is simpl! an unshielded twisted pair
transmission line consisting of two insula
conductors twisted together.
local loop
local line
subscriber loop
an! of these
3-2. It is an audible signal comprised of tw
fre5uencies 3$% '( and ))% '(
dial tone
ringbac& signal
bus! tone
call waiting tone
3-3. It enables the destination station of a
telephone call to displa! the name of the
telephone number of the calling part! befo
the telephone is answered.
conference call
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)3. 8888888 occurs when two or more signals
combine in a linear de"ice such as a passi"e
networ& or a small7signal amplifier
A. non7linear mi6ingB. linear7phase filteringC. linear summingD. bandlimiting
)). ne of the following is not a useful 5uantit!for comparing the noise performance of
recei"ers?
A. input noise "oltageB. e5ui"alent noise resistanceC. noise temperatureD. noise figure
)$. A single7stage amplifier has a 2%%7i'(
bandwidth and a "oltage gain of 1%% at room
temperature. Assume that the e6ternal noise
is negligible and that a 17m" signal is
applied to the amplifiers input. Calculatethe output noise "oltage if the amplifier has
a $7dB F and the input noise is generated b!
a 27&ilo ohm resistor.
A. $+.$ n>B. )$ u>C. $-$.+ n>D. 3$+ u>
)+. ln a communication s!stem, which of the
following reduces the information capacit! of
the s!stem
A. linear7phase filteringB. mi6ingC. bandlimitingD. modulation
)#. 8888888occurs when two or more signals are
combined in a non7linear de"ice such as a
diode or large7signal amplifier.
A. modulationB. non7linear summingC. oscillationD. non7linear filtering
). easuring ph!sical condition of some remote
location and transmitting this data for
anal!sis is the process of
A. elemetr!B. InstrumentationC. odulationD. ultiple6ing
)-. It is defined as an! undesirable electrical
energ! that falls within the passband of the
signal.
call wait
call forwarding
caller lD
3-). he largest cable used in a local loop
usuall! 3+%% pair of copper wires placed
underground or in conduit.
feeder cable
distribution cable
drop wire
drop7wire cross7connect cables
3-$. A weighting techni5ue that assumes a
perfect recei"er onl! therefore its weight
cur"e corresponds to the fre5uenc! of the
onl!
relati"e noise weighting
abo"e relati"e noise weighting
C7message noise weighting
psophometric noise weighting
3-+. he difference between the absolute de
of all fre5uencies.
relati"e phase dela!
phase dela! distortion
absolute phase dela!
phase distortion
3-#. A special t!pe of line conditioning tha
sets the minimum re5uirements for signal7t
noise ratio an nonlinear distortion
A7t!pe line conditioning
B7t!pe line conditioning
C7t!pe line conditioning
D7t!pe line conditioning
3-. It is a form of incidental phase
modulation G a continuous uncontrolled
"ariations in the (ero crossings of a sign
crosstal&
co7channel interference
phase =itter
spi&es
3--. A t!pe of crosstal& which is a direct
result of nonlinear amplification in analo
communications s!stem
linear crosstal&
transmittance crosstal&
nonlinear crosstal&
coupling crosstal&
)%%. he operator of the telephone instrumen
subscriber
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A. interferenceB. noiseC. splatterD. out7of7band signaling
$%. 888888noise that is present regardless of
whether there is a signal present or not.
A. atmospheric noise
B. correlatedC. uncorrelatedD. internal
$1. A three stage amplifier has an input stage
with noise ratio of $ and a power gain of $%.
0tages 2 and 3 ha"e a noise ratio of 1% and
power gain of 1%%%. Calculate the noise
figure for the o"erall s!stem.
A. ).$$ dBB. #.1) dBC. + dBD. $.1 dB
$2. ln communications s!stem, noise is most
li&el! to affect the signal
A. at the transmitterB. in the channelC. in the information sourceD. at the information
$3. /hich of the following is not true
A. ' mi6ers are generall! noisier than '
amplifiers
B. Impulse noise "oltage is independent ofbandwidth
C. hermal noise is independent of the
fre5uenc! at which it is measuredD. Industrial noise is usuall! of the impulse
t!pe
$). lt is a t!pe of noise that is generated
outside the de"ice of circuit.
A. shot noiseB. noise "oltageC. thermal noiseD. e6ternal noise
$$. 88888 noise is a naturall! occurring
electrical disturbances which is commonl!
called static electricit!.
A. ransit7time noiseB. E6traterrestrial noiseC. 0olar noiseD. Atmospheric noise
$+. /hat is the noise whose source is in a
categor! different from that of the other
three.
destination
source
terminal
)%1. lt is a s!stem of sensors, switches and
other electronic and electrical de"ices th
allows subscriber to gi"e instructions
directl! to the switch without ha"ing to g
through the operator
manual switching s!stem
automated switching s!stem
common switching s!stem
crossbar switching s!stem
)%2. oll offices are connected to other tol
offices with 888888.
intertoll trun&s
intratoll trun&s
interoffce trun&s
intraoffice trun&s
)%3. he highest ran&ing office in the DDD
networ& in term of si(e of the geographica
area ser"ed an the trun& options a"ailable
End office
0ectional center
;egional center
oll center
)%). 'e in"ented the automatic line selector
which led to the automatic telephone s!ste
Ale6ander Bain
Ale6ander 4raham Bell
homas Edison
Almon 0trowger
)%$. It allows customers to change to a
different ser"ice and still &eep the same
phone number
changing
porting
transporting
portabilit!
)%+. B! definition, speech power is e5ual to
u reading minus 888888.
1. dB
)dB
1.) dB
3dB
)%#. /hen the telephone set is in the 888888
state, a direct current from the central
office @C flows through the transmitter
recei"er of the handset.
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A. solar noiseB. cosmic noiseC. atmospheric noiseD. galactic noise
$#. A microwa"e antenna with an e5ui"alent noise
temperature of 2$ H is coupled through a
networ& with an e5ui"alent noise temperature
of 3% H to a microwa"e recei"er with an
e5ui"alent noise temperature of +% H referredto its input. Calculate the noise power at
its input for a 27' bandwidth.
A. 3.1$ f/B. ).3$ f/C. 2.12 f/D. 1.2) f/
$. he process of impressing a low7fre5uenc!
information signals onto a high7fre5uenc!
carrier signal is called 8888888 .
A. demodulationB. oscillationC. modulationD. amplification
$-. A silicon "aractor diode e6hibits a
capacitance of 2%%p at (ero bias. lf it is
in parallel with a +%7p capacitor and a 2%%7
u' inductor, calculate the range of resonant
fre5uenc! as the diode "aries through a
re"erse bias of 3 to 1$ >.
A. +#- &'( to 2.13 '(B. -++ &'( to 1.1$ '(
C. 3$$ &'( t% 3.12 '(D. 1)3 &'( to ).$3 '(
+%. A process where the recei"ed signal is
transformed into its original form
A. demodulationB. dampingC. amplificationD. oscillation
+1. It is the process of changing the amplitude
of a relati"el! high fre5uenc! carrier signal
in proportion with the instantaneous "alue
the modulating signal.
A. re5uenc! modulationB. Digital modulationC. 9hase modulationD. Analog modulation
+2. ost of the power in an A signal is in the
A. CarrierB. Jpper sidebandC. ower sidebandD. odulating signal
on7hoo&
off7hoo&
semi7hoo&
hoo&7in
)%. !pe of loop signaling which in"ol"es
opening and closing the loop to dial to or
through the central office
ear and mouth
duple6
loop pulsing
interoffice calling
)%-. Base stations transmitter output power
Impro"ed obile elephone 0!stem @I0
1%%7/ to 2%%7/ range
2%%7/ to 3%%7/ range
1$%7/ to )%%7/ range
3%%7/ to )%%7/ range
)1%. he chipping rate of /CDA @J0
3.) cps
3.+)) cps
1.2$ cps
1.22 cps
)11. A techni5ue that di"ides the group of
channels into smaller groupings or segment
of mutuall! e6clusi"e fre5uenciesK cell
sites, which are within the reuse distance
assigned their own segment of the channel
group
sectoring
duali(ation
partitioning
segmentation
)12. he actual "oice channel where mobile
users communicate directl! with other mobi
or wireline subscriber through the base
station
control channel
forward channel
re"erse channel
"oice channel
)13. 0uper"isor! Audio ones @0A ha"e the
following e6cept?
$-)% '(
$-#% '(
+%%% '
+%3% '(
)1). Each cell site contains a
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+3. Amplitude modulation is the same as
A. linear mi6ingB. analog multiple6ingC. signal summationD. multiple6ing
+). he shape of the amplitude7modulated wa"e is
called 88888888
A. sidebandsB. modulating signalC. en"elopeD. carrier signal
+$. In a diode modulator, the negati"e half of
the A wa"e is supplied b!
A. uned circuitB. ransformerC. CapacitorD. Inductor
++. It is a term used to describe the amount of
amplitude change present in an A wa"eform.
A. coefficient of modulationB. depth of modulationC. modulation inde6D. an! of these
+#. /hen the modulation inde6 in an A wa"e is
greater than one it will
A. splatterB. o"ermodulationC. buc&7shotD. an! of these
+. he ideal "alue of modulation inde6 in A
A. 1B. %C. 1%%D. infinit!
+-. /hen the amplitude of the information in an
A modulator is e5ual to (ero, what is the
"alue of the modulation inde6
A. 1B. %C. 1%%D. infinit!
#%. Amplitude modulation can be produced b!
A. 'a"ing the carrier "ar! a resistanceB. 'a"ing the modulating signal "ar! a
capacitanceC. >ar!ing the carrier fre5uenc!D. >ar!ing the gain of the amplifier
;epeater
Control computer
Direct7lin& to a branch e6change
ouch7tone processor
)1$. A class ll mobile phone using A90 has
E;9 of
7+ dB/
7) dB/
2 dB/
+ dB/
)1+. he wideband designation in /ideband7CD
@/CDA denotes a bandwidth of
2.$ '(
3 '(
).$ '(
$ '(
)1#. An automobile tra"els at +%&mLhr. ind
time between fades if the car uses a 9C0
phone at 1-%% '(.
2.) ms
3.) ms
).# ms
$.1 ms
)1. A cellular s!stem is capable of coping
with handoffs once e"er! 2 minutes. 0uppos
this s!stem is in the cit! with ma6imum ca
speeds of +$ &mLhr. /hat is the ma6imum ce
radius for this urban s!stem
1.% &m
3 &m
$ &m
2 &m
)1-. 'ow wide is the spectrum bandwidth of a
single 40 carrier
1+ &'(
2%% &'(
1%% &'(
$% &'(
)2%. Changing the time order of digital
information before transmission to reduce
effect of burst errors in the channel.
progression
interlea"ing
epoch
ra&ing
)21. he bandwidth of /CDA is 888888 larger
than 40.
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#1. /hen the modulation inde6 is e5ual to (ero,
the total transmitted power is e5ual to 88888
.
A. one of the sidebandsB. carrierC. double sidebandsD. an A wa"e
#2. /hen the modulation ta&es place prior to the
output element of the final stage of thetransmitter, prior to the collector of the
output transistor in a transistori(ed
transmitter, this is called 88888.
A. high7le"el modulationB. low7le"el modulationC. (ero7modulationD. constant modulation
#3. A circuit that monitors the recei"ed signal
le"el and sends a signal bac& to the ; and
I amplifiers to ad=ust their gain
automaticall!
A. automatic phase controlB. automatic gain controlC. automatic fre5uenc! controlD. automatic "olume control
#). /hen the modulation ta&es place in the final
element of the final stage where the carrier
signal is at its ma6imum amplitude it is
called 888888.
A. constant modulationB. (ero7modulation
C. low7le"el modulationD. high7le"el modulation
#$. If a superheterod!ne recei"er is tuned to a
desired signal at 1%%% &'( and its con"ersion
@local oscillator is operating at 13%% &'(,
what would be the fre5uenc! of an incoming
signal that would possibl! cause image
reception
A. 1+%% &'(B. 23%% &'(C. 12$% &'(D. 3)2% &'(
#+. /hen modulation re5uires a much higher
amplitude modulating signal to achie"e a
reasonable percent modulation, this is called
A. high7le"el modulationB. low7le"el modulationC. (ero7modulationD. constant modulation
##. Amplitude modulators that "ar! the carrier
amplitude with the modulating signal b!
$
1$
2%
2$
)22. lt is the process in which the same set
fre5uencies can be allocated to more than
cell, pro"ided that the cells are separate
b! a sufficient distance
fre5uenc! reuse
handoff
clustering
radio sur"e!
)23. A connection is momentaril! bro&en duri
the cell7to7cell transfer is called 888888
hard handoff
soft handoff
medium handoff
light handoff
)2). ransmission from mobile stations to th
base stations is called
forward lin&
re"erse lin&
control lin&
user lin&
)2$. lt is a database in the 9C0 networ& tha
stores information about the user, includi
home subscription information and what
supplementar! ser"ices the user is subscri
to.
"isitor location register
home location register
e5uipment identification register
authentication register
)2+. Determine the transmit power for a CDA
mobile unit that is recei"ing a signal fro
the base station at 1%% dBm
12 dBm
2) dBm
3+ dBm
1) dBm
)2#. /hen transmitting digital information,
"oice transmission is inhibited, this is
called 888888
5uieting
muting
blan&7and7burst
an! of these
)2. A metropolitan area of 1%%% s5uare &m i
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passing it through an attenuator wor& on
principle of
A. ;ectificationB. ;esonanceC. >ariable resistanceD. Absorption
#. A circuit which function is to raise the
amplitude of the source signal to a usable
le"el while producing minimum nonlineardistortion adding as little thermal noise as
possible.
A. power amplifierB. non7linear amplifierC. buffer amplifierD. preamplifier
#-. A circuit that has a low7gain, high7input
impedance linear amplifier which is used to
isolate the oscillator from the high7power
amplifiers
A. power amplifierB. bandpass filterC. signal dri"erD. buffer amplifier
%. /ith high7le"el transmitters, which of the
following is not a primar! function of the
modulator circuit
A. It pro"ides the circuitr! necessar! for
modulation to occurB. It ser"es as a final amplifierC. It ser"es as a fre5uenc! up7con"erterD. It ser"es as a mi6er
1. It is a form of amplitude distortion
introduced when positi"e and negati"e
alternations in the A modulated signal are
not e5ual.
A. phase shiftB. carrier shiftC. amplitude "ariationsD. fre5uenc! shift
2. A carrier is simultaneousl! modulated b! two
sine wa"es with modulation indices of %.3 and
%.), the total modulation inde6
A. is 1B. cannot be calculated unless the phase
relations are &nownC. is %.$D. is %.#
3. he component used to produce A at "er! high
fre5uencies is a
A. "aractorB. thermistor
to be co"ered b! cells with a radius of 2
'ow man! cell sites would be re5uired,
assuming he6agonal cells
#2
#3
#)
#$
)2-. ;efers to a land station in a maritime
mobile ser"ice
coast station
maritime station
coast earth station
ship earth station
)3%. Class of orthogonal spreading coded use
in CDA communication.
Color code
/alsh code
9C0 code
CDA
)31. ln a spread spectrum s!stem, the tenden
for stronger signals to interfere with the
reception of wea&er signals.
near7far field
near7far effect
direct7se5uence
spread7spectrum
)32. acrocells ha"e base stations transmit
power between 888888.
3/ to #/
1/to +/
2/ to /
%.1/to $/
)33. It is when the area of a cell, or
independent component co"erage areas of a
cellular s!stem, is further di"ided, thus
creating more cell areas.
cell splitting
cell clustering
cell partitioning
cell sectoring
)3). It is when a mobile unit mo"es from one
cell to another from one compan!s ser"ice
area to another compan! s ser"ice area
roaming
handoff
hando"er
paging
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C. ca"it! resonatorD. 9IF diode
). It is also &nown as upward modulation
A. carrier shiftB. amplitude "ariationsC. fre5uenc! shiftD. phase shift
$. Also &nown as downward modulation
A. carrier shiftB. amplitude "ariationsC. fre5uenc! shiftD. phase shift
+. It is a form of amplitude modulation where
signals from two separate information sources
modulate the same carrier fre5uenc! at the
same time without interfering with each
other.
A. M90HB. MJAC. 90HD. 0H
#. A recei"er has a d!namic range of 1 dB. It
has %.$$ n/ sensiti"it!. Determine the
ma6imum allowable input signal.
A. $- m/B. +- m/C. #- m/D. m/
. he information sources modulate the samecarrier after it has been separated into two
carrier signals are at -% degrees out of
phase with each other.
A. M90HB. MJAC. 90HD. 0H
-. Jnmodulating 5uadrature A signal re5uires a
carrier reco"er! circuit to reproduce the
original carrier fre5uenc! and phase and two
balanced modulators to actuall! demodulate
the signals. his is called 888888 .
A. as!nchronous detectionB. 5uadrature demodulationC. s!nchronous detectionD. 5uadrature detection
-%. Muadrature amplitude modulation is also &nown
as 888888 .
A. phase di"ision multiple6ingB. phase di"ision modulationC. phase amplitude multiple6ing
)3$. It is a 3)7bit binar! code that represe
the 1%7digit telephone number
electronic serial number
s!stem identification
digital color code
mobile identification number
)3+. he bandwidth of /CDA is 888888 times
larger than CDAone.
)
$
+
#
)3#. ;ecei"e channel 22 is #%.++ '(. ;ecei
channel 23 is
#%.3+ '(
#%.+3 '(
#%.-+ '(
#%.+- '(
)3. In mobile wireless communication, the
radio e5uipment and the propagation path.
0
air interface
direct lin&
mobile interface
)3-. he signaling tone ma! be transmitted o
the "oice channel during a call in what
fre5uenc!
2$ &'(
2% &'(
1$ &'(
1% &'(
))%. 0tation in the mobile ser"ice not inten
to be used while in motion.
base station
fi6ed station
coast station
land station
))1. ln the 40 s!stem, a Nsmart card
containing all user information, which is
inserted into the phone before use.
I0I
IEI
I0
0I
))2. Determine the number of channels per
cluster of a cellular telephone area
comprised of 1% clusters with se"en cells
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D. phase angle modulation
-1. Amplitude modulation generated at a "er! low
"oltage or power amplitude is &nown as
A. high7le"el modulationB. low7le"el modulationC. collector modulationD. minimum modulation
-2. It is the first stage of the recei"er and istherefore often called the recei"er front
end.
A. i6erB. ; sectionC. ocal oscillatorD. I stage
-3. In an 00B transmitter, one is most li&el! to
find a
A. class C audio amplifierB. tuned modulatorC. class B ; amplifierD. class A ; output amplifier
-). he section of the recei"er than down7
con"erts the recei"ed ; fre5uencies to
intermediate fre5uencies.
A. ; sectionB. ocal oscillatorC. 9ower amplifierD. i6er
-$. he circuit that demodulates the A wa"e and
con"erts it to the original informationsignal.
A. 9ower amplifierB. ocal scillatorC. DetectorD. I section
-+. A collector modulator has a suppl! "oltage of
)>. he pea&7to7pea& amplitude of the
modulating signal for 1%% percent modulation
is
A. 2) >
B. ) >C. -+ >D. 12% >
-#. A recei"er parameter that is used to measure
the abilit! of the recei"er to accept a gi"en
band of fre5uencies and re=ect all others.
A. 0electi"it!B. M7factorC. sensiti"it!D. bandwidth
each cluster and 1% channels in each cell.
#% channels per cluster
#%% channels per cluster
#%%% channels per cluster
# channels per cluster
))3. Determine the channel capacit! if #
macrocells with 1% channels per cell is sp
into ) minicells
12% channels per area
3+% channels per area
2% channels per area
)+% channels per area
))). echni5ue of spread spectrum that brea&
message into fi6ed7si(e bloc&s of data wit
each bloc& transmitted in se5uence e6cept
the different carrier fre5uenc!.
spread spectrum
time7di"ision multiple6ing
fre5uenc!7hopping
direct se5uence
))$. A base and mobile is separated b! $ &m
/hat is the propagation time for a signal
tra"eling between them
1).$ usec
1.- usec
2%. usec
1+.# usec
))+. A digital identification associated wit
cellular s!stem
IF
E0F
0A
0I
))#. A new regulation issued b! the Fational
elecommunications Commission pro"iding fo
the guideline for mobile personal
communication ha"ing a global co"erage usi
satellite.
F
49C0
40
AC0
)). he following are the t!pical cluster s
e6cept
3
#
12
1$
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-. he noise reduction ratio achie"ed b!
reducing the bandwidth is called
A. d!namic rangeB. noise figureC. bandwidth efficienc!D. bandwidth impro"ement
--. It is the minimum ; signal le"el that can be
detected at the input to the recei"er and
still produce a usable demodulatedinformation signal.
A. selecti"it!B. sensiti"it!C. M7factorD. bandwidth
1%%. or ideal A which of the following is
true
A. m O %B. m O 1C. m 1D. m P 1
1%1. A collector7modulated transmitter has a
suppl! "oltage of 2)> and a collector
amplitude of the modulating signal for 1%%
percent modulation with a load impedance as
seen b! the collector of ) ohms is
A. +/B. 12/C. 1/D. 2)/
1%2. ;ecei"er sensiti"it! is also &nown as
A. pinch7offB. thresholdC. compression pointD. shoot7off point
1%3. It is defined as the difference in
decibels between the minimum input le"el
necessar! to discern the signal and the input
le"el that will o"erdri"e the recei"er and
produce distortion.
A. d!namic range
B. noise figureC. bandwidth efficienc!D. bandwidth impro"ement
1%). It is the input power range o"er which the
recei"er is useful
A. d!namic rangeB. noise figureC. bandwidth efficienc!D. bandwidth impro"ement
1%$. It is defined as the output power when the
))-. 9ro"ides a centrali(ed administration a
maintenance point for the entire networ& a
interfaces with the public telephone netwo
through the telephone wireline "oice trun&
and data lin&s
90F
0
central offices
0C
)$%. lt is a digital telephone e6change loca
in the 0 that is the heart of a telepho
s!stem
mobile switching center
electronic switching center
gatewa! switching center
electronic mobile switching center
)$1. A database in the 9C0 networ& that stor
information pertaining to the identificati
and t!pe of e5uipment that e6ist in the
mobile unit.
"isitor location register
home location register
e5uipment identification register
authentication register
)$2. /hen the signal from a mobile cellular
unit drops below a certain le"el, what act
occurs
he unit is Nhanded oftQ to a closer cell.
he call is terminated.
he 0 increases power le"el.
he cell site switches antenna.
)$3. A method of transmitting data on A90
cellular telephone "oice channels that are
temporar! unused.
cellular digital pac&et data
digital color code
control mobile attenuation code
electronic serial code
)$). A "ehicle tra"els through a cellular
s!stem at 1%% &m per hour. Appro6imatel! h
often will handoffs occur if the cell radi
is 1% &m.
12min
1) min
1+ min
1min
)$$. In the 40 s!stem, a telephone number t
is uni5ue to a gi"en user, worldwide.
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; amplifier response is 17dB less than the
ideal linear gain response
A. 17dB compression pointB. 17dB threshold pointC. 17dB shoot7off pointD. 17dB pinch7off point
1%+. It is the measure of the abilit! of a
communications s!stem to produce, at the
output of the recei"er an e6act replica ofthe original source information.
A. sensiti"it!B. thresholdC. selecti"it!D. fidelit!
1%#. A 00B signal is generated around a 2%%7&'(
carrier. Before filtering the upper and lower
sidebands are separated b! 2%% '(. Calculate
the filter M re5uired to obtain )%7dB
suppression.
A. 1$%%B. 1-%%C. 2$%%D. 2%%%
1%. 'e de"eloped the first successful radio
s!stem
B.E. Alpine
F.0. Hapan!
E.'. Armstrong
A.C.0. >an 'eel
1%-. ;esults whene"er the phase angle ofsinusoidal wa"e is "aried with respect to
time.
angle modulation
digital modulation
amplitude modulation
pulse modulation
11%. ln the spectrum of a fre5uenc!7modulated
wa"e
the carrier fre5uenc! disappears with a large
modulationthe amplitude of an! sideband depends on the
modulation inde6
the total number of sidebands depends on the
modulation inde6
the carrier fre5uenc! cannot disappear
111. /hat is the fre5uenc! swing of an
broadcast transmitter when modulated +%R
+% &'(
)$ &'(
I0
IEI
I0I
0I
)$+. An area di"ided into he6agonal shapes t
fit together to form a hone!comb pattern i
called 888888.
cluster
transport area
cell
area of responsibilit!
)$#. Determine the channel capacit! of a
cellular telephone area comprised of twel"
macrocell with ten channels per cell
12 channels per area
12% channels per area
12%% channels per area
12%%% channels per area
)$. ransmission from base stations to mobi
stations is called 888888.
forward lin&
re"erse lin&
control lin&
user lin&
)$-. A de"ice that was constructed from mirr
and selenium detectors that transmitted so
wa"es o"er a beam of light.
lightphone
photophone
cameraphone
walletphone
)+%. /hich fiber7optic s!stem is better
3 repeaters
repeaters
11 repeaters
2% repeaters
)+1. /hat is the fre5uenc! limit of a copper
wire
appro6imatel! %.$ '(
appro6imatel! 1.% '(
appro6imatel! )% 4'(
none of the abo"e
)+2. he! were granted patents for scanning
transmitting tele"ision images through
uncoated fiber cables.
Baird and 'ansel
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3% &'(
2$ &'(
112. >ar!ing the fre5uenc! of a constant7
amplitude carrier directl! proportional to
the amplitude of the modulating signal at a
rate e5ual to the fre5uenc! of the modulating
signal.
Amplitude modulation
Angle modulation
9hase modulation
re5uenc! modulation
113. he amount of fre5uenc! de"iation from the
carrier center fre5uenc! in an transmitter
is proportional to what characteristic of the
fre5uenc! signal
amplitude
fre5uenc!
phase
shape
11). It is a modulation where the angle of a
wa"e carrier is "aried from its reference
"alue.
Amplitude modulation
Angle modulation
Analog modulation
Digital modulation
11$. Both and 9 are t!pes of what &ind of
modulation
amplitude
phase
angle
dut! c!cle
11+. >ar!ing the phase of a constant7amplitude
carrier displacement proportional to the
amplitude of the modulating signal at a rate
e5ual to the fre5uenc! of the modulating
signal.
Amplitude modulation
Angle modulation
9hase modulationre5uenc! modulation
11#. he difference between phase and fre5uenc!
modulation
is purel! theoretical because the! are the same
in practi"e
is too great to ma&e the two s!stems compatible
lies in the poorer audio response of phase
modulation
lies in the different definitions of the
Boc&ham and Hao
Hapron and Hec&
aiman and 0chawlow
)+3. he product of the bit rate and distanc
of a fiber7optic 4bits7&mLs. /hat is the
ma6imum rate at $ &m
1%% bitsLs
2%% bitsLs
)%% bitsLs
1%%% 4bitsLs
)+). Appro6imatel! what is the fre5uenc! lim
of the optical fiber
2% '(
1 '(
1%% '(
)% 4'(
)+$. he! e6perimented with light transmissi
cables through bundle of fibers and lead t
the de"elopment of fle6ible fiberscope.
ownes, 0chawlow and Hao
aiman, Hao and Boc&ham
aurer, Hapron and Hec&
>an 'eel, 'op&ins, Hapan!
)++. 9hotodiodes operate properl! with
forward bias
re"erse bias
neither forward nor re"erse bias
either forward or re"erse bias
)+#. 'e coined the term Nfiber opticsQ in 1
Hapan!
Hao
Boc&ham
Hec&
)+. he! wrote a paper describing how it wa
possible to use stimulated emission for
amplif!ing light wa"es @laser as well as
microwa"es @maser
heodore aimanHC Hao and 4A Boc&ham
Charles ownes and Arthur 0chawlow
Hapron, Hec& and aurer
)+-. he scientist who built the first optic
maser
Charles ownes
4A Boc&ham
heodore aiman
AC0 >an 'eel
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modulation inde6
11. he relati"e angular displacement of the
carrier phase in radians with respect to the
reference phase is called 888888.
phase de"iation
carrier de"iation
fre5uenc! de"iation
information de"iation
11-. If the amplitude of the modulating signal
decreases, the carrier de"iation
increases
decreases
remains constant
goes to (ero
12%. n an signal, ma6imum de"iation occurs
at what point on the modulating signal
(ero7crossing points
pea& positi"e amplitudes
pea& negati"e amplitude
both pea& positi"e and negati"e amplitudes
121. he amount of oscillator fre5uenc!
increase and decrease around the carrier
fre5uenc! is called 88888 .
fre5uenc! de"iation
phase shift
intelligence fre5uenc!
baseband
122. he relati"e displacement of the carrier
fre5uenc! in hert( in respect to its
unmodulated "alue is called 88888 .
fre5uenc! de"iation
phase de"iation
information de"iation
carrier de"iation
123. A pre7emphasis circuit pro"ides e6tra
noise immunit! b!
boosting the bass fre5uencies
amplif!ing the higher audio fre5uencies
preamplif!ing the whole audio band
con"erting the phase modulation to
12). It is the instantaneous change in phase of
the carrier at a gi"en instant of time and
indicates how much phase of the carrier is
changing with respect to its reference phase.
instantaneous fre5uenc!
instantaneous fre5uenc! de"iation
instantaneous phase
)#%. A single fiber can handle as man! "oice
channels as cables.
a pair of copper conductors
a 1$%%7pair cable
a $%%7pair cable
a 1%%%7pair cable
)#1. he! proposed a new communication mediu
using cladded fiber cables.
Hao and Boc&ham
aiman, Hao and Boc&ham
Hapron, Hec& and aurer
aiman and 0chawlow
)#2. An incident ra! can be defined as
a light ra! reflected from a flat surface
a light directed toward a surface
a diffused light ra!
a light ra! that happens periodicall!
)#3. De"eloped an optical fiber with losses
less than 2 dBL&m
Hao and Boc&ham
aiman, Hao and Boc&ham
aiman and 0chawlow
Hapron, Hec& and aurer
)#). he band of light fre5uencies that are
high to be seen human e!e
Jltra"iolet
>isible light
Infrared
Sellow
)#$. /hich of the following is the fastest
light sensor
9IF photodiode
9hoto"oltaic diode l >
9hotodiode
A"alanche photodiode
)#+. ;ange of infrared
3+% nm to ))% nm
+#% nm to 1%
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instantaneous phase de"iation
12$. Calculate the amount of fre5uenc!
de"iation caused b! a limited noise spi&e
that still causes an undesired phase shift of
3$ degrees when the input fre5uenc! is $ &'(.
2.)% &'(
3.%$ &'(
1.2- &'(
).)$ &'(
12+. /hich of the following determines the rate
of carrier de"iation
intelligence fre5uenc!
fre5uenc! de"iation
carrier fre5uenc!
broadband fre5uenc!
12#. It is the precise phase of the carrier at
a gi"en instant of time.
instantaneous phase de"iation
instantaneous phase
instantaneous fre5uenc! de"iation
instantaneous fre5uenc!
12. In 9, a fre5uenc!7shift occurs while what
characteristic of the modulating signal is
changing
shape
phase
fre5uenc!
amplitude
12-. In , it is a de"ice that in which
amplitude "ariations are deri"ed in response
to fre5uenc! or phase "ariations.
detector
discriminator
demodulator
recei"er
13%. a6imum fre5uenc! de"iation of a 9 signal
occurs at
(ero7crossing points
pea& positi"e amplitudes
pea& negati"e amplitude
pea& positi"e and negati"e amplitude
131. 0ince noise phase7modulates the wa"e,
as the noise sideband fre5uenc! approaches
the carrier fre5uenc!, the noise amplitude
remains constant
is decreased
is increased
une"en rough surface
light scattering
)#. he band of light fre5uencies to which
human e!e will respond
Infrared
>isible light
Jltra"iolet
Cosmic ra!s
)#-. aser light is "er! bright because it i
pure
white
coherent
monochromatic
)%. /hich of the following is the fastest
light sensor
9IF photodiode
9hoto"oltaic diode
9hotodiode
A"alanche photodiode
)1. ;ange of wa"elength of "isible light
+#% nm to 1%isible
Jltra"iolet
)3. /hich of the following terms best
describes the reason that light is refract
at different angles
9hoton energ! changes with wa"elength
ight is refracted as a function of surface
smoothness
he angle is determined partl! b! a and b
he angle is determined b! the inde6 of the
materials
)). ;ange of wa"elengths of ultra"iolet
+#% nm to 1%
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8/15/2019 Questions for Est - NS 47
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is e5uali(ed
132. It is the instantaneous change in
fre5uenc! of the carrier and is defined as
the first time deri"ati"e of the phase
de"iation.
instantaneous fre5uenc!
instantaneous fre5uenc! de"iation
instantaneous phase
instantaneous phase de"iation
133. 0ince noise phase7modulates the wa"e,
as the noise fre5uenc! approaches the carrier
fre5uenc!, the noise
remains constant
is decreased
is increased
is e5uali(ed
13). It is the precise fre5uenc! of the carrier
at a gi"en instant of defined as the first
time deri"ati"e of the instantaneous phase.
instantaneous fre5uenc!
instantaneous fre5uenc! de"iation
instantaneous phase
instantaneous phase de"iation
13$. It is the output7"ersus7input transfer
functions for modulators which gi"e the
relationship between the output parameter
changes in respect to specified changes in
the input signal.
fre5uenc! de"iation
de"iation sensiti"it!
transconductance cur"e
phase de"iation
13+. /hen the modulating fre5uenc! is doubled,
the modulation inde6 is hal"ed, and the
modulating "oltage remains constant. he
modulation s!stem is
amplitude modulation
phase modulation
fre5uenc! modulation
an! of the abo"e
13#. In 9, carrier fre5uenc! de"iation is not
proportional to?
modulating signal amplitude
carrier amplitude and fre5uenc!
modulating signal fre5uenc!
modulator phase shift
13. o compensate for increases in carrier
fre5uenc! de"iation with an increase in
pure
intense
coherent
monochromatic
)+. he coating in a fiber helps protect fi
from moisture, which reduces the possibili
of the occurrence of a detrimental phenome
called
0tatic fatigue
echanical fatigue
0tress fatigue
Coating fatigue
)#. he term critical angle describes
the point at which light is refracted
the point at which light becomes in"isible
the point at which light has gone from the
refracti"e mode to the reflecti"e mode
the point at which light has crossed the
boundar! la!ers from one inde6 to another
). he ratio of the speed of light in air
the speed of light in another substance is
called the
speed factor
inde6 of reflection
inde6 of refraction
speed gain
)-. he three essential t!pes of fiber
commonl! used toda! e6cept
9lastic core and cladding
9lastic core and glass cladding
4lass core and 4lass cladding @0C0
4lass core and 9lastic cladding @9C0
)-%. /hat phenomenon will result if the glas
fiber is e6posed to long periods of high
humidit!
stress fatigue
core corrosion
stress corrosion
cladding corrosion
)-1. he law that states N /hen "isible ligh
of high7fre5uenc! electromagnetic radiatio
illuminates a metallic surface, electrons
emittedQ is &nown as 888888
Einstein law of photon
arconi*s law
a6well*s law
9lan&*s law
)-2. Both EDs and lDs operate correctl! wi
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modulating signal fre5uenc!, what circuit is
used between the modulating signal and phase
modulator
low7pass filter
high7pass filter
phase shifter
bandpass filter
13-. Indicate which one of the following is not
an ad"antage of o"er A?
better noise immunit! is pro"ided
lower bandwidth is re5uired
the transmitted power is more useful
less modulating power is re5uired
1)%. /ith phase modulation, the ma6imum
fre5uenc! de"iation occurs during what "alue
of the modulating signal
positi"e pea& "alue
rms "alue
negati"e pea& "alue
(ero crossings
1)1. /ith fre5uenc! modulation, ma6imum
fre5uenc! de"iation occurs 888888 of the
modulation signal.
positi"e pea& "alue
both positi"e and negati"e pea& "alue
negati"e pea& "alue
(ero crossings
1)2. In an stereo multiple6 transmission,
the
a sum signal modulates the 1-7&'( subcarrier
difference signal modulates the 1-7&'( subcarrier
difference signal modulates the 37&'( subcarrier
difference signal modulates the +#7&'( subcarrier
1)3. /ith phase modulation, pea& phase
de"iation is called 888888 .
modulation inde6
fre5uenc! de"iation
phase de"iation
instantaneous phase
1)). he produced b! 9 is called
9
indirect
indirect 9
1)$. In a broadcast superheterod!ne recei"er,
the
forward bias
re"erse bias
neither forward nor re"erse bias
either forward or re"erse
)-3. An! energ! le"el abo"e the ground state
called 888888.
Formal state
Abo"e7ground state
E6cited state
0pontaneous state
)-). he process of deca!ing from one energ!
le"el to another energ! le"el is called
888888.
0pontaneous emission
E6cited emission
Absorption
An! of these
)-$. he process of mo"ing from one energ!
le"el to another is called
0pontaneous emission
E6cited emission
Absorption
0pontaneous deca!
)-+. ost fiber optic light sources emit lig
in which spectrum
"isible
infrared
ultra"iolet
67ra!
)-#. A pac&et of energ! which is e5ual to th
difference between the two energ! le"els.
9hotons
Electron"olt
Muantum
Muanta
)-. It is the science of measuring onl! lig
wa"es that are "isible to the human e!e.
;adiometr!
9hotometr!
phthalmolog!
ptometr!
)--. he refracti"e inde6 number is
a number which compares the transparenc! of a
material with that of air
a number of assigned b! the manufacturer to t
fiber in 5uestion
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local oscillator operates below the signal
fre5uenc!
mi6er input must be tuned to the signal fre5uenc!
local oscillator fre5uenc! is normall! double the
I
; amplifier normall! wor&s at )$$ &'( abo"e the
carrier fre5uenc!
1)+. If the amplitude of the modulating signal
applied to a phase modulator is constant, the
output signal will be
(ero
the carrier fre5uenc!
abo"e the carrier fre5uenc!
below the carrier fre5uenc!
1)#. o pre"ent o"erloading of the last I
amplifier in the recei"er, it should use the
s5uelch
"ariable sensiti"it!
"ariable selecti"it!
double con"ersion
1). he pea&7to7pea& fre5uenc! de"iation is
sometimes called 888888 .
phase de"iation
pea& phase de"iation
carrier swing
instantaneous fre5uenc!
1)-. A 1%%7'( carrier is de"iated $% &'( b! )7
&'( signal. he modulation inde6 is
$
12.$
2%
1$%. /ith angle modulation, it is defined as
the ratio of the fre5uenc! de"iation actuall!
produced to the ma6imum fre5uenc! de"iation
allowed b! law stated in percent form.
modulation inde6
percent modulation
fre5uenc! de"iation
phase de"iation
1$1. In a broadcast s!stem, the input 0LF O
). Calculate the worst7case 0LF at the output
if the recei"er*s internal noise effect is
negligible.
1-.?1
21.+?1
23?1
1$?1
a number which determines the core diameter
a term for describing core elasticit!
$%%. It is a science of measuring light
throughout the entire electromagnetic
spectrum
;adiometr!
9hotometr!
phthalmolog!
ptometr!
$%1. /hich light emitter is preferred for hi
speed data in a fiber7optic s!stem
incandescent
ED
neon
laser
$%2. ight intensit! is generall! described
terms of 888888 and measured in 88888888.
uminous flu6 densit!, umens per unit area
uminous flu6 intensit!, umens per unit area
uminous flu6 densit!, umens per unit "olume
uminous flu6 intensit!, umens per unit "olu
$%3. In radiometric terms, it measures the r
at which electromagnetic wa"es transfer li
energ!
ptical radiation
ptical impedance
ptical illusion
ptical power
$%). It is described as the flow of light
energ! past a gi"en point in a specified
time.
ptical radiation
ptical impedance
ptical illusion
ptical power
$%$. he term single mode and multimode are
best described as
a number of fibers placed into fiber7optic ca
the number of "oice channels each fiber can
support
the number of wa"elengths each fiber can supp
the inde6 number
$%+. ptical power is sometimes called 88888
;adiant emission
;adiant power
;adiant flu6
;adiant optics
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1$2. Is a circuit in which the carrier is
"aried in such a wa! that its instantaneous
phase is proportional to the modulating
signal.
fre5uenc! modulators
amplitude modulators
phase modulators
mi6ers
1$3. In a ratio detector
the linearit! is worse than in a phase
discriminator
stabili(ation against signal strength "ariations
is pro"ided
the output is twice that obtainable from the
similar phase discriminator
the circuit is the same as in a discriminator,
e6cept that the diodes are re"ersed
1$). he ma6imum de"iation of an carrier is
2 &'( b! a ma6imum modulating signal of )%%
'(. he de"iation ratio is
%.2
$
)%
1$$. he unmodulated carrier is a single7
fre5uenc! sinusoid commonl! called 888888 .
unrest fre5uenc!
rest fre5uenc!
fre5uenc!7modulated fre5uenc!
carrier fre5uenc!
1$+. It is a circuit in which the carrier is
"aried in such a wa! that its instantaneous
phase is proportional to the integral of the
modulating signal.
phase modulator
phase de"iator
amplitude de"iator
fre5uenc! modulator
1$#. he t!pical s5uelch circuit
cuts off an audio amplifier when the carrier is
absent
eliminates the ; interference when the signal is
wea&
cuts off an I amplifier when the A4C is ma6imum
cuts off an l amplifier when the A4C is minimum
$%#. In refraction that occurs in airLglass
interfaces, among the "isible light, which
bent the most
red
"iolet
!ellow
green
$%. iber7optic cables with attenuations of
1., 3.), $.-, and 1 dB are lin&ed togeth
he total loss is
#.$ dB
1-. dB
2-.1 dB
+$% dB
$%-. In stereophonic broadcast, the center
fre5uenc! of each 0CA subcarrier shall be
&ept at all times within 888888 '( of the
authori(ed fre5uenc!.
2%%
3%%
)%%
$%%
$1%. 0awtooth generator circuits produce the
scanning raster, but the s!nc pulses are
needed for
linearit!
timing
&e!stoning
line pairing
$11. /hich of the following camera tubes has
minimum lag
>idicon
9lumbicon
0aticon
Iconoscope
$12. he ser"ice area in standard A broadca
is described as 888888 there is no fading
signal.
Class A
0econdar!
Class B
9rimar!
$13. he "ertical field7scanning fre5uenc! i
888888 '(.
3%
+%
$2$
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8/15/2019 Questions for Est - NS 47
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1$. Categor! of media with some form of
conductor that conduit in which
electromagnetic signals are contained.
A. 4uided
B. Balanced
C. Jnguided
D. Jnbalanced
1$-. he conducti"e connections between
elements which carr! signals.
A. ransmission lines
B. Antenna
C. re5uenc! allocations
D. oad
1+%. Calculate the characteristic impedance for
a line that e6hibits an inductance of ) n'Lm
and 1.$ pLm
A. 3+.$ ohms
B. $1.+ ohms
C. 22 ohms
D. 2).$ ohms
1+1. Categor! of media which are wireless
A. 4uided
B. Balanced
C. Jnguided
D. Jnbalanced
1+2. It is a medium or an! ph!sical facilit!
used to propagate electromagnetic signals
between two locations in a communications
s!stem.
A. transmission medium
B. channel allocation
C. fre5uenc! allocation
D. an! of these
1+3. It is a metallic conductor s!stem used to
transfer electrical energ! from one point to
another using electrical current flow.
A. transmitter
B. multiple6ers
C. recei"er
D. transmission line
1+). A &ind of wa"e where the displacement is
in the direction of propagation.
A. trans"erse
B. longitudinal
C. re"erse
D. perpendicular
1$,#$%
$1). A ).$7'( signal which is e5ual to the
difference between the picture and sound ;
carrier fre5uencies in a +7'( > channel.
Audio fre5uenc!
>ideo fre5uenc!
lntercarrier fre5uenc!
0ubcarrier fre5uenc!
$1$. A s!stem where the modulated ; picture
and sound carrier signals are distributed
a cable networ&, instead of wireless s!ste
CC>
A>
CA>
0A>
$1+. A class A station is limited in ante
height of 888888feet abo"e a"erage terrain
1%%%
2%%%
)%%%
$%%%
$1#. /hat circuit in the > recei"er is used
de"elop the high "oltage needed to operate
the picture tube
low7"oltage power suppl!
hori(ontal output
"ertical sweep
s!nc separator
$1. he modulated picture carrier wa"e
includes the composite "ideo signal as the
a"erage carrier le"el
s!mmetric en"elope of amplitude "ariations
lower sideband without the upper sideband
upper en"elope without the lower en"elope
$1-. /ith which emission t!pe is the capture
effect more pronounced
C/
00B
A
$2%. he hue of color s!nc phase is
red
c!an
blue
!ellow7green
$21. 'ow much is the e5ui"alent internal
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1+$. Calculate the capacitance per meter of a
$%7ohm load cable that has an inductance of
$$ n'Lm.
A. 13 p
B. 1 p
C. 2% p
D. 22 p
1++. he desirable 0/; on a transmission line
is
A. %
B. 1
C. 2
D. infinit!
1+#. A &ind of wa"e where the direction of
displacement is perpendicular to the
direction of propagation
A. trans"erse
B. longitudinal
C. re"erse
D. perpendicular
1+. A short7circuited half7wa"elength line
acts li&e a
A. parallel resonant circuit
B. series resonant circuit
C. oscillator
D. C circuit
1+-. Electromagnetic wa"es that tra"el along a
transmission line from the source lo the
load.
A. re"erse wa"es
B. trans"erse wa"es
C. incident wa"es
D. longitudinal wa"es
1#%. Electromagnetic wa"es that tra"el from the
load bac& toward the source.
A. incident wa"es
B. trans"erse wa"es
C. forward wa"es
D. reflected wa"es
1#1. 0ound tra"els appro6imatel!
A. 22%% feet per second
B. 11%% feet per second
C. $$% feet per second
D. +%% feet per second
1#2. Determine the surge impedance for a
parallel wire, air dielectric with a ratio of
resistance of the electron beam with a 1.2
beam current at 2$ &>
) nano ohms
3% ohms
2%. mega ohms
1$.+ &ilo ohms
$22. he difference between the picture and
sound carrier fre5uencies for channel 3
is888888 '(.
3.$
+).$
).$
+.#$
$23. ;efers to the de"iation of the operatin
fre5uenc! of a cr!stal oscillator from its
nominal "alue due to temperature "ariation
drift
flasho"er
fre5uenc! de"iation
de"iation ratio
$2). It is the measure of how man! picture
elements can be reproduced
definition
resolution
detail
an! of these
$2$. A 3.$7'( subcarrier signal for color
tele"ision
'ue signal
>ideo signal
Audio signal
Chroma signal
$2+. A class D station shall ha"e an
authori(ed power not e6ceeding 888888 watt
2%
1$
1%
$
$2#. /hich of the following is not a benefit
cable >
ower7cost reception
4reater stabilit!
ess noise, stronger signal
9remium cable channels
$2. he width of the "ertical s!nc pulse in
the 9hilippine > s!stem is
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the spacing between conductors and the
diameter of 3
A. 2$% ohms
B. 21% ohms
C. 1% ohms
D. 21$ ohms
1#3. he rate at which the periodic wa"e
repeats
A. wa"elength
B. amplitude
C. period
D. fre5uenc!
1#). he distance of one c!cle occurring in
space
A. wa"elength
B. amplitude
C. period
D. fre5uenc!
1#$. Classification of transmission line where
both conductors currentK one conductor
carries the signal the other conductor is the
return path
Differential transmission lines
Jnbalanced lines
Coa6ial cables
Balun
1#+. A shorted half7wa"e line at the operating
fre5uenc! acts li&e
capacitor
Inductor
series resonant circuit
parallel resonant circuit
1##. /hat is the characteristic impedance of a
coa6ial line, air dielectric with a ratio of
the diameter of the outer and inner conductor
e5ual to 1.$
2).3 ohms
2+.+ ohms
13.2 ohms
1 ohms
1#. Currents that flow in opposite direction
in a balanced wire pair is called
ongitudinal circuit currents
;e"erse circuit currents
rans"erse circuit currents
etallic circuit currents
1#-. Currents that flow in same direction in a
21'
3'
'
%.$'
$2-. erm in communication which is referred
to send out in all directionQ
announce
broadcast
transmit
media
$3%. he number of frames per second in the
9hilippine > s!stem is
+%
2+2 T
).$
3%
$31. It means multiple outlines of edges to
right in the picture.
ghosting
ringing
fading
snowing
$32. In the sawtooth wa"eform for linear
scanning,
the linear rise is for fl!bac&
the complete c!cle includes trace and retrace
the sharp re"ersal in amplitude produces trac
the beam mo"es faster during trace and retrac
$33. he purpose of pre7emphasis and de7
emphasis in broadcasting is to?
increase the high fre5uenc! amplitude
impro"e the audio harmonic
decrease the low fre5uenc! amplitude
impro"e the 0LF ratio
$3). he part of the "isible spectrum where
camera pic&up tubes ha"e the greatest outp
is
red
blue
!ellow7green
infrared
$3$. he t!pe of modulation of the sound
carrier signal is 888888.
pulse modulation
phase modulation
amplitude modulation
fre5uenc! modulation
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balanced wire pair is called
ongitudinal currents
;e"erse circuit currents
rans"erse circuit currents
In7phase currents
1%. A secret de"ice used to connect a balanced
transmission line to an unbalanced load
0lotted lines
0tub
Balun
Muarterwa"e lines
11. he most common t!pe of balun used in
relati"el! high fre5uenc!
Farrowband
Cho&e
0lee"e
All of these
12. A pattern of "oltage and current
"ariations along the transmission line not
terminated in its characteristic impedance is
called
an electric field
radio wa"es
standing wa"es
a magnetic field
13. A t!pe of parallel7conductor transmission
lines consists of simpl! of two parallel
wires, closel!7spaced and separated b! air.
wisted pair
pen7wire lines
Coa6ial cables
win pair
1). A t!pe of parallel7conductor transmission
lines which is essentiall! the same as open7
wire transmission line e6cept that the
spacers between the conductors are replaced
with a continuous solid dielectric that
ensures uniform spacing along the entire
cable
wisted pair
pen7wire lines
Coa6ial cables
win lead
1$. /hat is the range of si(e of wires of a
twisted pair
A/4 1+ to A/4 2+
A/4 1) to A/4 2$
A/4 1% to A/4 2%
$3+. A "ideo or audio signal that can be use
directl! to reproduce the picture and soun
baseband signal
broadband signal
electromagnetic wa"e signal
modulated signal
$3#. Class B station should ha"e an E;9 n
e6ceeding 888888 &/.
$%
)%
3%
2%
$3. /hat techni5ue is used to permit hundre
of > signals to share a common cable
fre5uenc! modulation
mi6ing
fre5uenc! di"ision multiple6ing
time di"ision multiple6ing
$3-. Another name for the hori(ontal retrace
a > recei"er is the
ringing
burst
damper
fl!bac&
$)%. In the 9hilippine color tele"ision s!st
the intercarrier fre5uenc! in '(, is
3.$
3.$#-$)$
).$
)$.#$
$)1. In channel 1) @)#% to )#+ '(, the 3.$
'( color signal is transmitted at
)#1.2$ '(
)#3.2$ '(
)#).3 '(
)#$.2$ '(
$)2. Interlaced scanning eliminates
snowing
flic&er
distortion
fading
$)3. Beam alignment magnets for the camera t
are ad=usted while roc&ing which control
optical focus
electrical focus
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A/4 12 to A/4 2
1+. /hat is the characteristic impedance of a
coa6ial line, pol!ethel!ene dielectric with
the ratio of the diameter of the outer and
and the inner conductor of 2.$
)3.$ ohms
23.) ohms
3+.2 ohms
2-. ohms
1#. In A/4, the higher the wire gauge 888888
the higher the diameter and the lower the
resistance
the smaller the diameter and the higher the
resistance
the smaller the diameter and the higher the
conductance
the larger the diameter and the higher the
resistance
1. !pe of twisted pair wire cable that
consists of two copper wires where each wire
is separatel! encapsulated in 9>C insulation.
0hielded wisted 9air
win lead
Jnshielded wisted 9air
pen wire line
1-. A shorted 5uarter7wa"e line at the
operating fre5uenc! acts li&e
series resonant circuit
parallel resonant circuit
capacitor
inductor
1-%. he minimum number of twist for a J9 is
wo twist per foot
wo twist per meter
hree twist per foot
hree twist per meter
1-1. A dela! using ;47ALJ cable is to e6hibit
a $7ns dela!. Calculate the re5uired length
of the cable.
).$# ft
1.23 ft
+.2 ft
3.) ft
1-2. An open7circuited 5uarter7wa"elength line
acts li&e a
parallel resonant circuit
series resonant circuit
beam current
shading
$)). /hat is a fre5uenc! discriminator
An generator
A circuit for detecting
A circuit for filtering two closel! ad=acent
signals
An automatic bandwidth circuit
$)$. A s!stem used in tele"ision field
operation to ma&e on7the7spot "ideo tape
recordings using portable > cameras and
>;s.
0F4
EF4
'AC
A>
$)+. Class B station shall ha"e an
authori(ed transmitter power not e6ceeding
&/.
1%
1%%
1%%%
1%%%%
$)#. he total bandwidth of an F0C > signa
is
3.$ '(
).$ '(
+ '(
1%.# '(
$). ;eferred to the oscillator signal Nlea&
throughQ from a propert! neutrali(ed
amplifier such as a master oscillator powe
amplifier.
carrier
stra! signal
bac& wa"e
loss wa"e
$)-. Interlacing is used in tele"ision to
produce the illusion of motion
ensure that all lines on the screen are scann
not merel! the alternate ones
simplif! the "ertical s!nc pulse train
a"oid flic&er
$$%. Coa6ial cable for distribution s!stem h
an impedance of
$% ohms
#$ ohms
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oscilllator
C circuit
1-3. e"el or Categor! of J9 cable which is
suitable onl! for "oice
4rade telephone signals and "er! low7speed data
applications
e"el 1 or Cat 1
e"el 3 or Cat 3
e"el 2 or Cat 2
Cat )
1-). An antenna is being fed b! a properl!
terminated two7wire transmission line. he
current in the line at the input end is 3A.
he surge impedance of the line is $%% ohms.
'ow much power is being supplied to the line
3.1 &/
2.$ &/
1.+ &/
).$ &/
1-$. e"el or Categor! of J9 cable which was
de"eloped for IEEE %2.$ to&en ring local
area networ&s operating at a transmission
rates of ) bps
e"el 1 or Cat 1
e"el 3 or Cat 3
e"el 2 or Cat 2
Cat )
1-+. If the period of one complete c!cle of a
radio wa"e is %.%%%%%1 s, what is the
wa"elength
3%% m
2%% m
1%% m
)%% m
1-#. If the two towers of a -$%7&'( antenna are
separated b! 12% electrical degrees, what is
the tower separation in feet
231 ft
23$ ft
1#+ ft
3)$ ft
1-. Categor! of J9 used for "irtuall! an!
"oice or data transmission rate up to 1+
bps, has a minimum of 3 turns per inch.
Categor! $e
Categor! )
Categor! $
Categor! 3
1$% ohms
3%% ohms
$$1. he a"erage "oltage "alue of the 3 $
modulated chrominance signal is
(ero for most colors
close to blac& for !ellow
the brightness of the color
the saturation of the color
$$2. /hen does broadcast station conduct an
e5uipment test
during da! time
during night time
during e6perimental period
at an! time
$$3. It causes the picture information to
spread out or crowded at one end of the
raster compared to the opposite end.
linear scanning
interlaced scanning
non7linear scanning
retrace
$$). If the camera cannot be placed far awa!
enough to include e"er!thing in the scene,
change the lens to one with a
lower f rating
higher f rating
longer focal length
shorter focal length
$$$. !pe of radio communication transmissio
utili(ing fre5uenc! modulation techni5ue
tele"ision "ideo
broadcasting in $3$71+%+ &'(
single sideband ' transmission
tele"ision audio
$$+. he amount of color in the picture or
color intensit! is the 888888.
color le"el
chroma le"el
saturation
an! of these
$$#. ne of the earl! radio transmitters whi
produced &e!ed carrier generating purer
wa"eform than spar& transmitter, used for
high powered ; transmission and are limit
to radio fre5uenc! of about $%% &'(.
Arc transmitter
'artle! transmitter
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1--. he mismatch between the antenna and
transmission line impedances cannot be
corrected for b!
using an C matching networ&
ad=usting antenna length
using a balun
ad=usting the length of transmission line
2%%. Categor! of J9 that was designed for data
transmission rates up to 2% bps
Categor! $e
Categor! )
Categor! $
Categor! 3
2%1. >ariation of CA$ cables that are intended
for data transmission rates up to 2$% bps
Categor! $e
Categor! 2
Categor! +
Categor! 3
2%2. A t!pe of twisted7pair wherein its wires
and dielectric are enclosed in a conducti"e
metal slee"e called a foil.
09
win lead
J9
Jnshielded win lead
2%3. It is the name gi"en to the area between
the ceiling and the roof in a single7store!
building or between the ceiling and the floor
of the ne6t higher le"el in a multistor!
building.
attic
rooftop
plenum
ceiling
2%). It consists of center conductor surrounded
b! dielectric material, then a concentric
shielding, and an en"ironmental protection
outer =ac&et.
wisted pair
Coa6ial cable
win lead
pen wire
2%$. In transmission lines, it refers to the
wo"en stranded mesh or braid that surround
some t!pes of coa6ial cables
4rounding
0hielding
0par& transmitter
re5uenc! transmitter
$$. A techni5ue where segments of "ideotape
are =oined b! erasing and recording to cre
a single program.
mas&ing
segmenting
editing
programming
$$-. It is the pro"ision of "oice communicat
using Internet 9rotocol @I9 technolog!,
instead of traditional circuit switched
technolog!.
>I9
Bluetooth
/II
/IA:
$+%. Bluetooth enabled electronic de"ices
connect and communicate wirelessl! through
short7range, ad hoc networ&s &nown as
88888888.
nanonet
scatternet
piconet
netnet
$+1. Each de"ice can simultaneousl! communic
with up to 8888888 other de"ices within a
single piconet.
$
1%
#
$+2. he core specification "ersion of
Bluetooth that uses Enhanced Data ;ate @ED
>ersion 1.%
>ersion 2.%
>ersion 1.2
>ersion 2.1
$+3. Bluetooth technolog! operates in the
888888 band.
I0
C band
0I
Hu band
$+). Bluetooth technolog! operates in the ba
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Degaussing
An! of these
2%+. A coa6ial cable with one la!er of foil
insulation and one la!er of braided
shielding.
Bac&up shielding
emporar! shielding
Dual shielding
Interference shielding
2%#. At "er! high fre5uencies, transmission
lines are used as
tuned circuits
antennas
insulators
resistors
2%. he cumulati"e sum of the direct, ground7
reflected, and surface wa"es is referred to
as 888888.
0pace wa"e
4round wa"e
0&! wa"e
Direct wa"es
2%-. he D la!er of the ionosphere reflects
888888wa"es.
and '
> and
and >'
> and
21%. A di"ersit! scheme wherein the same radio
signal is repeated or transmitted more than
once.
polari(ation di"ersit!
field component di"ersit!
time di"ersit!
fre5uenc! di"ersit!
211. he disad"antage of ground wa"e
propagation is
4round wa"es re5uire a relati"el! high
transmission
4round wa"es are limited to "er! low, low and
medium fre5uencies re5uiring large antennas
4round losses "er! considerabl! with surface
material
An! of these
2.) to 2.)$ 4'(
2.)2 to 2.)) 4'(
2.) to 2.$2 4'(
2.3 to 2.)$ 4'(
$+$. he hopping rate of bluetooth is
1%%% hopsLsec
1+%% hopsLsec
1$%% hopsLsec
2$%% hopsLsec
$++. echnolog! used b! Bluetooth designed t
reduce interference between wireless
technologies sharing the 2.) 4'( spectrum.
A'
D000
D
'00
$+#. he signal hops among 8888888 fre5uenci
at 1 '( inter"als to gi"e a high degree o
interference immunit!.
%
#
1
#-
$+. Class 3 radios used for Bluetooth
technolog! ha"e a range of up to
1 ft
2 ft
3 ft
) ft
$+-. Class 2 radios used for Bluetooth most
commonl! found in mobile de"ices ha"e a ra
of 888888.
1% ft
2% ft
1$ ft
3% ft
$#%. Class 1 radios used primaril! in
industrial use cases ha"e a range of
1%% meters
2$ meters
1% meters
$% meters
$#1. Bluetooth technolog! uses 888888 of pow
2.+ m/
2.$ m/
2. m/
2.# m/
-
8/15/2019 Questions for Est - NS 47
31/52
212. A range of microwa"e fre5uencies more
easil! passed b! the atmosphere than the
others is called a
window
critical fre5uenc!
g!ro fre5uenc! range
resonance in the atmosphere
213. lt is simpl! the orientation of the
electric field "ector in respect to the
surface of the Earth
9olari(ation
/a"efront
;a!s
9ower densit!
21). or an isotropic antenna radiating 1%%/ of
power, what is power, what is power densit!
1%%% m from the source
1.-- u/Lm
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, '
',
,
,
21-. /hen microwa"e signals follow the
cur"ature of the earth, it is &nown as
the arada! effect
ducting
tropospheric scatter
ionospheric scatter
22%. lf the polari(ation "ector rotates 3+%
degrees as the wa"e mo"es one wa"elength
through space and field strength is e5ual at
all angles of polari(ation, the polari(ation
is 888888.
>erticall! polari(ed
'ori(ontall! polari(ed
Circularl! polari(ed
Ellipticall! polari(ed
221. 888888 tra"els essentiall! in a straight
line between the transmit and the recei"e
antennas
Direct wa"es
0&! wa"es
0pace wa"es
0urface wa"es
222. >ariations brought about the re"olution of
the earth around the sun
weather "ariation
c!clical "ariation
diurnal "ariation
seasonal "ariation
223. he dielectric strength of air is about
3>Lm. Arching is li&el! to ta&e place at
field strengths greater than that. /hat is
the ma6imum power densit! of an
electromagnetic wa"e in air
)% 4/LmD a
based
9E471
9E47)
9E472
9E47#
$). 9E4 standard on which such products as
>ideo CD and 93 are based
9E471
9E47#
9E4721
9E473
$$. 9E4 standard for multimedia for the fi
and mobile web
9E471
9E47)
9E472
9E47#
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is caused b! reflections from the ground
arises onl! with spherical wa"eforms
will occur when the wa"es pass through a large
slot
ma! occur around the edge of a sharp obstacle
22+. he critical fre5uenc! at a particular
time is 11.+ '(. /hat is the J for a
transmitting station if the re5uired angle of
incidence for propagation to a desired
destination is #% degrees
3) '(
)$ '
)% '
1$.$ '
22#. he rate at which energ! passes through a
gi"en surface area in free space is called
capture power
capture area
captured power densit!
power densit!
22. A radio wa"e mo"es from air @ relati"e
permitti"it! of 1 to glass @relati"e
permitti"it! of #. . Its angle of incidence
is 3% degrees. /hat is the angle of
refraction
1%.3