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8/12/2019 bel paper no 2
1/21
BEL Placement Paper 2
(Technical-Electronics-IInd)
1. Resistivity of silicon in ohms cm. is approx. equal to
a. 5 !. 11" c. "#$ d. 1-%
". Rsistivity of&ermanium in ohms cm. is approx. equal to
a. 5 !. 1-1" c. 5$ d. 1-%
#. The num!er of free electrons'cu!ic cm intrinsic &ermanium at room temperature is approx. equal to
a. 1.511 !. ".511# c. 1 d. 51%
. The num!er of free electrons'cu!ic cm of intrinsic silicon at room temperature is approx. equal to
a. 1.511 !. ".511# c. 1 d. 51%
5. The for!idden ener*y *ap for silicon is
a. 1.1e+ !. %,e+ c. .,e+ d. 1.,e+
%. The for!idden ener*y *ap for &ermanium is
a. 1.1e+ !. %,e+ c. .,e+ d. 1.,e+
,. type material is formed !y the addition of the follo/in* (penta valent )atom in n to semiconductormaterial
a. 0ntimony
!. 0rsenic
c. hosphorous
d. 0ny of the a!ove
2. type material is formed !y the addition of the follo/in* 3Trivalent4 atom tn to semiconductormaterial
a. oron !. &allium c. Indium d. 0ny of the a!ove
. Impurity atoms that produces type material !y its addition in semiconductor is called
a. 6onar !. 0cceptor c. 7onductor d. Insulator
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1. Impurity atoms that produces type material !y its addition in semiconductor is called
a. 6onar !. 0cceptor c. 7onductor d. Insulator
11. 6ynamic resistance of a diode Rd is if volta*e chan*es is 6+d and the current chan*e is 6 Id
a. 6 +d ' 6 Id!. 6 Id ' 6 +d
c. 1 ' 6+d
d. 1 ' 6 Id
1". oint contact diodes are preferred at very hi*h frequency8 !ecause of its lo/ 9unction
a. 7apacitance and inductance
!. Inductance
c. 7apacitance
1#. Identify the circuit *iven !elo/
a. 06 *ate
!. :R *ate
c. Rectifier
d. :R *ate
1. Identify the circuit *iven !elo/
a. 06 *ate
!. :R *ate
c. Rectifier
d. :R *ate
15. 67 value of a ;alf /ave rectifier /ith Em as the pea$ value of the input is
a. .#12Em
!. .12Em
c. .512Em
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d. .%12Em
1%. 7han*e in
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d. one of these
"". Transition capacitance 7t of a +aricap diode /ith Bnee volta*e +t8 reverse volta*e +r and B8 theconstant !ased on semiconductor material and the construction technique C dependent on type of9unction is *iven !y
a. 1 ' B (+t D +r)'"
!. 1 ' B (+t D +r)
c. B ' (+t D +r)
d. B ' (+t D +r)1'
"#. 7t B ' (+t D +r) /here +t Bnee volta*e8 +r reverse volta*e8 B manufacturin* dependentconstant and dependent on type of 9unction8 for alloy 9unction the value of is
a. 1'# !. "'# c. 1'" d. 1'
". 7t B ' (+t D +r) /here +t Bnee volta*e8 +r reverse volta*e8 B manufacturin* dependentconstant and dependent on type of 9unction8 for diffused 9unction the value of is
a. 1'# !. "'# c. 1'" d. 1'
"5. In FGET8 the drain current Id is *iven !y (Idss drain H source saturation current +*s H &ate H sourcevolta*e8 +p the pinch off volta*e)
a. Idss31 H +p'+*s4
!. Idss(1 H +*s'+p)"
c. Idss31 H +*s'+p)
d. Idss(1 H +*s'+p)#'"
"%. The shado/ mas$ in colour tu!e is used to
a. Reduce -Ray emission
!. Ensure each !eam hits its o/n dots
c. Increase screen !ri*htness
d. rovide de*aussin* for the screen
",. Indicate /hich of the follo/in* si*nal is not transmitted in colour T+
a. J !. K c. R d. I
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"2. 0nother name for hori>ontal retrace in T+ receiver is the
a. Rin*in* !. urst c. 6amper d. Gly !ac$
". 0nother name for the colour sync in the colour T+ system
a. Rin*in* !. urst c. 6amper d. Gly !ac$
#. The ;+ anode supply for a picture tu!e of a T+ receiver is *enerated in the
a. Aains transformer
!. +ertical output sta*e
c. ;ori>ontal output sta*e
d. ;ori>ontal oscillator
#1. The output of vertical amplifier is
a. 6irect current
!. 0mplified vertical sync pulse
c. 0 sa/ tooth volta*e
d. 0 sa/ tooth current
#". In a transistor if 0lpha .28 current *ain is equal to
a. " !. 5 c. % d.
##. The active re*ion in the common emitter confi*uration means
a. oth collector and emitter 9unction is reverse !iased
!. The collector 9unction is for/ard !iased and emitter 9unction
c. The collector 9unction is reverse !iased and emitter 9unction is for/ared !iased
d. oth collector C emitter 9unction are for/ard !iased
#. The saturation re*ion in the common emitter confi*uration means that
a. oth collector C emitter 9unction are reverse !iased
!. The collector 9unction is for/ard !iased and emitter 9unction
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c. The collector 9unction is reverse !iased and emitter 9unction is for/ared !iased
d. oth collector C emitter 9unction are for/ard !iased
#5. The = of Red8 &reen C lue in 1= Lhite J is *iven !y
a. #=8 5=8 11=!. 5=8 #=8 11=
c. #=8 11=8 5=
d. ##.#=8 ##.5=8 #2.#=
#%. Equali>in* pulse /idth8 if ; is the ;ori>ontal sync rate
a. .% ; !. ., ; c. . ; d. .1% ;
#,. In a simple R7 net/or$ the !and/idth is equal to
a. 1'" p R7
!. R7 ' "
c. " 7 ' p R
d. " p ' R7
#2. The time constant of a R7 net/or$ is *iven !y
a. R7 !. 7'R c. R'7 d. one of these
#. Girst >ero crossin* of pulse frequency spectrum occurs at if d is the pulse /idth8 T is the pulserepetition rate
a. 1'd !. d'T c. T'd d. T
. The distortion less output characteristic of a net/or$ means
a. 7onstant amplitude and linear phase shift over frequency
!. @inear phase shift and amplitude need not !e constant
c. 0ny amplitude and phase
d. one of these
1. ?in*le side!and means suppressed
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a. 7arrier
!. 7arrier and one side !and
c. :ne side !and
d. one of these". In an amplitude modulated si*nal8 lo/er side !and frequency is equal to (if the carrier frequency isfc and modulation frequency is fm)
a. fm D fc !. fc H fm c. fm r fc d. fc ' fm
#. Aodulation index of the frequency modulation depends on
a. 0mplitude C frequency of the modulation si*nal
!. Grequency and amplitude of carrier si*nal
c. 7arrier frequency
d. one of these
. The L of the narro/ !and GA if modulatin* frequency is fm
a. # r fm !. " r fm c. ".5 r fm d. 1 r fm
5. Reactance tu!e modulator is $no/n for
a. GA !. 0A c. A d. 0A
%. and/idth and rise time product is
a. .#5 !. .5 c. .# d. .
,. Ener*y *ap8 @*8 for &ermanium at room temp 3#o B4 is
a. .,"e+ !. 1.1e+ c. 1.5#e+ d. ."e+
2. +olt equivalent of temperature +T8 at 11%o B is
a. .11+ !. .1+ c. 1.1%+ d. .1+
. Reverse saturation current of a &e.diode is in the ran*e of
a. m0 !. u0 c. n0 d. p0
5. 7ut-in volta*e + for silicon is approximately
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a. ."+ !. .%+ c. .+ d. 1.1+
51. Every 1o 7 rise in temp. the reverse saturation current
a. 6ou!les
!. ;alvesc. Triples
d. o chan*e
5". ;all effect /ith reference to Aetal or ?emiconductor carryin* a current I is placed in a transversema*netic field 8 an electric field E is induced in
a. arallel to
!. erpendicular to I
c. erpendicular to !oth C I
d. erpendicular to
5#. 1 e+ (electron volt) is equal toM
a. 1. r 1-" F
!. 1.% r 1-1 F
c. 1.% r 1-" F
d. 1.1% r 1-1 F
5. 6onar impurity is havin* a valency ofM
a. " !. # c. d. 5
55. 0cceptor impurity is havin* a valency of
a. " !. # c. d. 5
5%. Electron volt arises from the fact that if any electron falls throu*h a potential of 1 volt8 its $ineticener*y /ill
a. 6ecrease8 C potential ener*y /ill increase
!. Increase C potential ener*y decrease
c. e unaltered C potential ener*y decreases
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d. Increase C potential ener*y increase
5,. ;ole is created in a semiconductor material if one of follo/in* impurities are added
a. 0ntimony
!. 0rsenic
c. Indium
d. hosphorus
52. Excess electron is created !y
a. oran
!. &allium
c. Indium
d. 0rsenic
5. 0 snu!!er circuit is used across the ?7R to protect a*ainst
a. The di'dt of the anode current
!. The dv'dt turn on
c. @.di'dt of load inductance
d. one of these
%. &ermanium has the valency of
a. " !. # c. d. 5
%1. ?ilicon has the valency of
a. " !. # c. d. 5
%". ;ole acts as a free char*e carrier of polarity
a. e*ative
!. ositive
c. eutral
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d. one of these
%#. urst si*nal in T?7 system is 2 cycles of the frequency of
a. 7olour su! carrier
!. icture carrierc. ?ound carrier
d. one of these
%. 7olour su! carrier reference !urst is superimposed on the
a. ac$ porch of the each hori>ontal sync pulse
!. Gront porch of the each hori>ontal sync pulse
c. Gront porch of the each vertical sync pulse
d. ac$ porch of the each vertical sync pulse
%5. The la/ of mass action /ith reference to semiconductor technolo*y states that the product of freene*ative C positive concentration is a constant and
a. Independent of amount of donor and acceptor dopin*
!. 6ependent on amount of donor and independent of the amount acceptor impurity dopin*
c. 6epend on amount of !oth donor C acceptor impurity dopin*
d. one of these
%%. The snu!!er circuit used across ?7R is a simple
a. R-@ net/or$
!. R@7 net/or$
c. @7 net/or$
d. R7 net/or$
%,. To limit the rate of rise of ?7R anode current a small
a. Inductor is inserted in cathode circuit
!. Inductor is inserted in anode circuit
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c. 7apacitor is inserted in anode circuit
d. 7apacitor is inserted in cathode circuit
%2. Torque developed !y a 67 servo motor is proportional to the
a. roduct of po/er and time!. roduct of armature current and !ac$ emf
c. 0rmature volta*e and armature current
d. Gield volta*e and field current
%. roportional Inte*ral control
a. Reduces steady state error !ut reduces the for/ard *ain
!. Increases the for/ard *ain and reduces the steady state error
c. Increases the steady state error and increases the for/ard *ain
d. one of these
,. Increasin* the servo !and/idthM
a. Improves si*nal to noise ratio
!. Improves speed response and lo/ers si*nal to noise ratio
c. Improves po/er output
d. one of these
,1. otch filter is
a. @o/ pass filter
!. ;i*h pass filter
c. arro/ stop !and filter
d. arro/ pass !and filter
,". In T+ Receivers the Electron !eam deflection method used is
a. Electro static
!. Electro ma*netic
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c. Aa*netic
d. 0ll the a!ove
,#. In a line of si*ht communication the maximum ran*e R in miles !et/een the receiver antenna and
transmitter antenna of hei*ht ; in feet is approximatelya. R 1.# N;
!. R 1."# N;
c. R 1.5# N;
d. R ".# N;
,. In /avelen*th of the % A;> carrier frequency is
a. 1 metres
!. 15 metres
c. 5 metres
d. ".5 metres
,5. In standard T+ receivin* antenna the dipole element is
a. .5 of the /ave len*th
!. ."5 of the /ave len*th
c. 1.5 of the /ave len*th
d. 1. of the /ave len*th
,%. The characteristics of GET are similar toM
a. Triode
!. Tertode
c. entode
d. 6iode
,,. 7har*e coupled device is an array of capacitors /hose structure is similar toM
a. ?hift re*ister
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!. Glip-flop
c. 06 *ate
d. 0mplifier
,2. :perational amplifier characteristics are /hich of the follo/in*M
a. Infinite *ain
!. Infinite input impedance
c. :utput impedance is >ero
d. 0ll of the a!ove
,. The typical value of the open loop *ain in d of an amplifier at 67 /ith no feed!ac$ isM
a. to 1
!. 2 to
c. to 5
d. 5 to ,
2. The # d !and /idth means the frequency at /hich
a. The open loop volta*e *ain reduced to .,,
!. The open loop *ain reduced to unity
c. Aaximum volta*e of a si*nal is /ithout distortion
d. It is a medium /ave !and /idth of radio receiver
21. Rise time of an amplifier is defined as time required
a. To chan*e from to 1 = of its final value
!. To chan*e from to 5 = of its final value
c. To chan*e from 1 to = of its final value
d. To chan*e from 1 to 1 = of its final value
2". ;i*h speed amplifier desi*n emphasi>ed on
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a. Extremely small !and/idth
!. +ery slo/ response
c. Onity *ain !and/idth after 1 A;>
d. one of these2#. Tuned amplifier havin* the frequency ran*e !et/een
a. 15 B;> H 5 A;>
!. 1 ;> H 1 B;>
c. 1 B;> H 1" B;>
d. 5 A;> H 1 A;>
2. The resonance frequency of a tuned circuit made up of R8 @8 7 is *iven !y
a. 1'" pN@7
!. " pN@7
c. " p ' N@7
d. N@7 ' "
25. The volta*e follo/er can !e o!tained usin* operational amplifier
a. Lithout any feed!ac$
!. ?eries parallel feed!ac$ of unity
c. arallel feed!ac$
d. ?eries feed!ac$
2%. Gidelity of the amplifier is /hen
a. It is a linear amplifier
!. It does not add or su!tract any spectral components
c. It amplifier each component !y the same amount
d. 0ll of the a!ove
2,. Lhat /ould !e the output /hen t/o input sine /aves of frequency 5 B;> and 1 B;> passed
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throu*h an amplifier in the medium si*nal
a. 5 B;> and 1 B;>
!. 1 B;> and " B;>
c. 5 B;> and 15 B;>d. 0ll of the a!ove
22. The important application of ?chmitt tri**er is
a. To convert slo/ly varyin* input volta*e to a!rupt volta*e chan*e
!. To convert a!ruptly varyin* input volta*e into slo/ly varyin* output
c. To chan*e the frequency of the input
d. one of these
2. Aeanin* of decodin* is
a. inary addition
!. 6ata transmission
c. 6emultiplexin*
d. ?tora*e of !inary information
. 0pproximately ho/ many num!er of *ates are incorporated in ??@ chip
a. 1"
!. 1
c. Excess of 1
d. Excess of 1
1. The circuit dia*ram represents /hich one of the follo/in*
a. ;alf adder
!. Gull adder
c. Exor *ate
d. 06 *ate
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". Glip flop cannot !e called as
a. ista!le multivi!rator
!. 1 it memory unit
c. latch
d. com!inational circuit
#. The important use of lo/ pass filter in po/er supply is
a. To *et the re*ulation in the output volta*e
!. To filter out the ripple frequency
c. To increase the current ratin*
d. To convert 07 into 67
. inary equivalent of the decimal num!er 15 is
a. 111
!. 1111
c. 111
d. 111
5. In /hich of the follo/in* *ate the output /ill !e hi*h /hen all the maintained at hi*h level
a. :R
!. 06
c. 06
d. E:R
%. Lhich of the follo/in* definition is true in the 6e Aor*anPs theorem
a. Aultiplication sym!ols are replaced !y addition sym!ol
!. 0ddition sym!ols are replaced !y Aultiplication sym!ol
c. Each of the terms are expressed in the complementary form
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d. 0ll of the a!ove
,. 2"1'76 code fro a decimal num!er 1 is
a. 1 1 11
!. 1111c. 1111
d. one of these
2. 7om!inational circuit are mainly characteri>ed !y
a. :utput depends upon the previous state C presents state
!. :utput depends upon the input at that particular instant
c. :utput depends upon the presents state C the cloc$ state
d. :utput does not depends upon the input at all
. 0 flip flop is defined as
a. 0 !ista!le device /ith t/o complementary outputs
!. It is memory element
c. It /ill respond to input and it is a !asic memory element
d. 0ll of the a!ove
1. Gour !it code is called
a. i!!le
!. yte
c. Lord
d. Re*ister
0ns/erM-
1. c
". a
#. a
8/12/2019 bel paper no 2
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. !
5. a
%. !
,. d
2. d
. a
1. !
11. a
1". c
1#. !
1. a
15. a
1%. a
1,. a
12. d
1. c
". !
"1. a
"". c
"#. c
". a
"5. !
"%. !
",. c
8/12/2019 bel paper no 2
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"2. d
". !
#. c
#1. d#". d
##. c
#. d
#5. a
#%. c
#,. a
#2. d
#. a
. a
1. !
". !
#. a
. !
5. !
%. a
,. a
2. !
. !
5. !
51. a
5". c
8/12/2019 bel paper no 2
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5#. !
5. !
55. !
5%. !
5,. c
52. d
5. !
%. c
%1. c
%". !
%#. a
%. a
%5. a
%%. d
%,. !
%2. !
%. a
,. !
,1. c
,". c
,#. !
,. c
,5. a
,%. c
8/12/2019 bel paper no 2
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,,. a
,2. d
,. d
2. a21. c
2". c
2#. a
2. a
25. !
2%. d
2,. a
22. a
2. c
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1. a
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#. !
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5. !
%. d
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2. !
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1.a