questions for est - ns 47

8/15/2019 Questions for Est - NS 47

1/52

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


2/52

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


3/52

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


4/52

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&


5/52

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


6/52

)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


7/52

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.


8/52

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


9/52

+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.


10/52

#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


11/52

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


12/52

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


13/52

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


)+% 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$


14/52

-. 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.


15/52

; 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

)$. 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


16/52

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.


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.


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


17/52

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 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 and 0chawlow


)#). 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%


18/52

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



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%


19/52

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 phase


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 phase


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


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


20/52

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


21/52

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


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


22/52

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%

+%

$2$


23/52

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


24/52

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


25/52

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




26/52

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


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


27/52

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



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



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


28/52

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


29/52

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


30/52

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/


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


32/52

, '

',

,

,

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#


33/52

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

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