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C. a triac without a gate terminal• D. the *C+

5 . What re$ion lies 'et"een the pea/ point and (alley point of 0 emitter

characteristic?

• A. *aturation• B. Cut o2 C. Negative resistance• D. 3ositi(e resistance

54. What refers to the application of electronic theory technolo$yinstrumentation and computin$ system to 'iolo$ical research and medicalpro'lems?

• A. 6edical electronics• B. %enetics electronics• C. Biomedical en$ineerin$ D. Biome ical electronics

57. Which de(ice e#hi'its ne$ati(e resistance re$ion?

• A. Diac• B. riac• C. ransistor D. !"T

58. he 0 operates in "hat re$ion after pea/ point?

• A. Cut o2 B. Negative resistance• C. *aturation• D. 3ositi(e resistance

9. *C+ is a recti:er constructed of silicon material. *ilicon is chosen'ecause

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• A. it is the most a'undant material• B. of its stren$th and ru$$edness• C. it is much cheaper than any other material D. of its high temperature an power capabilities

1. A transduction principle used primarily in optical sensors.

• A. 3hotoconducti(e transduction B. #hotovoltaic trans uction• C. Electroma$netic transduction• D. 3ie;oelectric transduction

!. What is a solid state equi(alent of a $as :lled triode?

• A. riac• B. hyristor C. SCR• D. *C*

&. he supply (olta$e is $enerally uadric• C. *hoc/ley diode

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D. Diac

5. When the supply (olta$e e#ceeds the 'rea/o(er (olta$e of an *C+ it

A. starts con ucting• B. stops conductin$• C. conducts lea/a$e current• D. conducts terminal current

. he step response of a :rst order systems is $i(en 'y

• A. y t@ A9• B. y t@ A9 A 1e s1t A ! e s!t A &e s&t• C. y t@ A9 A 1e s1t A ! e s!t D. $%t& ' A ( ) A *e s*t

4. A feed'ac/ control system in "hich the controlled (aria'le is mechanicalposition.

• A. Closed-loop feed'ac/ control system• B. ,pen-loop feed'ac/ control system C. Servomechanism• D. 6echanical ser(omechanism

7. What is that (olta$e a'o(e "hen the *C+ enters the conduction re$ion?

• A. +e(erse 'rea/o(er (olta$e B. +orwar breakover voltage• C. oldin$ (olta$e• D. ri$$er (olta$e

8. A locus or path of the roots traced out on the s-plane as a parameter ischan$ed.

A. Root locus

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• B. yper'ola• C. 3ara'ola• D. Circle

49. A control system in "hich the output is related to the input 'y de(iceparameters only.

A. ,pen-loop control s$stem• B. Closed-loop control system• C. *er(omechanism• D. eed'ac/ control system

41. What is that (alue of current 'elo" "hich the *C+ s"itches from theconduction state to the for"ard 'loc/in$ re$ion under stated conditions?

A. ol ing current• B. or"ard current• C. +e(erse current• D. ri$$er current

4!. Which is equi(alent to a ;ener or a(alanche re$ion of the fundamentalt"o-layer semiconductor diode?

A. Reverse break own voltage• B. or"ard 'rea/do"n (olta$e• C. Brea/do"n (olta$e• D. Brea/o(er (olta$e

4&. What is the required $ate tri$$erin$ current of % ,?

A. /( mA• B. 19 mA• C. &9 mA

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• D. )9 mA

4). What is an automatic speed control de(ice usin$ the centrifu$al force onrotatin$ y"ei$hts as the feed'ac/ element?

• A. +e$ulator B. +l$wheel governor• C. ield control• D. hrottle (al(e

45. What is the sensin$ element of acceleration transducer?

• A. Damper• B. *prin$ C. Seismic mass• D. Crystal

4 . What are some areas "here % , is applica'le?

• A. Counters• B. 3ulse $enerators• C. 6ulti(i'rators D. All of the above

44. What %ree/ "ord "hich means Fs"itchG?

• A. +istor• B. rans C. Th$• D. hyristor

47. What is the typical turn-on time of an *C+?

A. * 0s• B. 5 Hs

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• C. 19 Hs• D. & Hs

48. An *C+ is a solid state equi(alent of "hich tu'e?

• A. riode B. 1as-2lle trio e• C. 3entode• D. etrode

79. he $ate of an *C+ is

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7&. What is one of the most "idely used sensin$ elements particularly forpressure ran$es hi$her than ! 63a?

• A. Bello"s

B. Bour on tube• C. Capsule• D. *trai$ht tu'e

7). Which of the follo"in$ can chan$e the an$le of conduction in *C+?

• A. Chan$in$ anode (olta$e B. Changing gate voltage•

C. +e(erse 'iasin$ the $ate• D. Chan$in$ cathode (olta$e

75. An *C+ is a mem'er of "hat family?

• A. hyrector• B. hyratron C. Th$ristor•

D. ransistor

7 . o" many pn unction does *C+s ha(e?

• A. "o• B. our C. Three• D. i(e

74. Which of the follo"in$ is J, a method primarily used for densitysensin$?

• A. *onic

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• B. +adiations• C. Ii'ratin$ element D. Di3erential

77. When *C+ starts conductin$ then

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• A. electroe#tracellu$raphy• B. electroemyo$raphy C. electroencephalograph$• D. electro(ectorcardio$raphy

8&. Acceleration transducers are also called

• A. $yros• B. force transducers• C. tachometers D. accelerometers

8). When an *C+ is com'ined to a s"itch it is considered as a

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84. he *C+ can e#ercise control o(er

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• c. B . Diac

19!. Iolta$e required to turn on any thyristor.

• a. ri$$er (olta$e b. Breakover voltage• c. Barrier (olta$e• d. *upply (olta$e

19&. Also /no"n as a four-layer diode.

• a. Diac b. Shockle$ io e• c. Kener diode• d. E

19). he thyristor counterpart of the uni unction transistor.

• a. 0 b. #!T• c. *B*• d. *C*

195. 6inimum current required to /eep a thyristor FonG.

a. ol ing current• '. ri$$er current• c. *upply current• d. Collector current

19 . A unidirectional-three terminal de(ice the most popular of thyristors.

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• a. *C*• '. riac• c. 0 . SCR

194. he an$le of an AC supply (olta$e durin$ "hich an *C+ is Fo2G.

• a. Conduction an$le b. +iring ela$ angle• c. +i$ht an$le• d. ,2 an$le

197. hyristors are most often used as

a. Switches• '. Ampli:ers• c. Bu2ers• d. Decoders

198. he total internal series resistance of the 0 .

• a. Bul/Ls resistance• '. otal resistance c. 7nterbase resistance• d. +M*

119. he most popular and typical 'rea/o(er (olta$e of a diac.

a. 8/ 4• '. 1 I• c. 7 I• d. ) I

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111. he pea/ (olta$e of a 30 is

• a. ID IBB• '. I% IBB c. 4D ) 41• d. IBB

11!. A 0 has N 9. 5 and is connected to a !9 I supply. What is its IEB1?

• a. 1! I b. *8.9 4• c. 1!.4 I• d. 1) I

11&. he three terminal semiconductor de(ice that acts in either direction.

a. Triac• '. *C+• c. Diac• d. *C*

11). he 3 of 30 stands for

a. #rogrammable• '. 3erformance• c. 3ea/• d. 3ost

115. he terminals of a 0 are

• a. %ate Anode Cathode• '. Anode Cathode• c. Emitter Base . :mitter; Base*; Base/

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11 . he lo"est current that can pre(ent the transition of a 0 fromconduction to 'loc/in$ re$ion.

• a. *"itchin$ current• '. Emitter current c. 4alle$ current• d. 3ea/ current

114. he *C* has ho" many $ate terminals?

• a. 9• '. 1 c. /• d. &

117. What de(ice has t"o terminals connected in in(erse-parallel that passin t"o directions?

• a. riac

b. Diac• c. *hoc/ley• d. *C+

118. What is the 'rea/o(er (olta$e of a 30 if it is connected to a 15 Isupply across the $ate terminal?

• a. 19.4 I• '. !&.4 I c. *5.< 4• d. 5.& I

1!9. he $ap 'et"een the for"ard 'loc/in$ re$ion and the for"ardconduction re$ion.

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• a. Band $ap• '. *"itchin$ re$ion• c. ump $ap . Negative resistance region

1!1. he cathode of the 30 is the counterpart of "hich terminal in 0 ?

• a. Anode• '. Base!• c. Emitter . Base*

1!!. An electronic s"itch that has the hi$hest sin$le de(ice current capacityand can "ithstand o(erloads 'etter.

• a. hyratrons• '. M$nitrons c. SCR• d. riac

1!&. %roup of de(ices "ith ) or more semiconductor layers.• a. ransistors• '. Diodes c. Th$ristors• d. ,p-Amps

1!). Mdentify "hich of the follo"in$ is a three layer de(ice.

• a. *C* b. Diac• c. riac• d. 30

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1!5. What de(ice can 'e modeled 'y a diode and t"o resistors?

• a. B• '. DMAC• c. *C+ . !"T

1! . A unction that is formed 'y addin$ controlled amounts of an impurity tothe melt durin$ crystal $ro"th is termed as

• a. used unction• '. 0ni unction•

c. Alloy unction . Dope =unction

1!4. A triac is a

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. Con ucts when triggere in both irection

1&9. 6inimum anode current to hold a thyristor at conduction.

• a. ri$$er• '. 6aintainin$ current c. ol ing current• d. hreshold (olta$e

1&1. %eneral term for semiconductor de(ices primarily used as s"itches.

• a. *hoc/ley• '. hyratron c. Th$ristor• d. +elay

1&!. A t"o-terminal unidirectional thyristor.

• a. DMAC b. Shockle$• c. +MAC• d. Diode

1&&. A thyristor is 'asically

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• '. riac• c. *0* . SCS

1&5. Which de(ice incorporates a terminal for synchroni;in$ purposes?

• a. Diac• '. riac c. S!S• d. *C+

1& . An *C+ is a

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1&8. A de(ice that cannot 'e tri$$ered 'y (olta$e of either polarity is

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b. 7gnitron• c. hyrector• d. *C+

1)). o" do you stop the conduction durin$ "hich the *C+ is alsoconductin$?

• a. +emo(e (olta$e $ate• '. Mncrease cathode (olta$e c. 7nterrupt ano e current• d. +educe $ate current

1)5. A series +C connected in parallel "ith an *C+ to eliminate falsetri$$erin$ is the

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• d. *"itchin$

1)7. he minimum emitter to 'ase (olta$e to tri$$er the 0 is the

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a. Con uction angle• '. irin$ delay an$le• c. Mnduction an$le• d. ,J an$le

15&. A four-element solid state de(ice that com'ines the characteristics of a'oth diodes and transistors.

• a. Iaractor• '. Kener diode• c. unnel diode . SCR

15). Electron tu'e equi(alent to solid state *C+.

• a. riode• '. I I6• c. C+ . Th$ratron

155. ind the t"o sta'le operatin$ conditions of an *C+. a. Con ucting an non-con ucting• '. ,scillatin$ and quiescent• c. J3J conduction and 3J3 conduction• d. or"ard conductin$ and re(erse conductin$

15 . o" do you stop conduction durin$ "hich *C+ is also conductin$?

• a. +emo(e (olta$e $ate• '. Mncrease cathode (olta$e c. 7nterrupt ano e current• d. +educe $ate current

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154. When an *C+ is tri$$ered or on conductin$ its electrical characteristicsare similar to "hat other solid-state de(ice as measured 'et"een itscathode and anode@?

a. The =unction io e• '. he (aractor diode• c. he tunnel diode• d. he hotcarrier diode

157. Which of the follo"in$ does not ha(e a 'ase terminal?

• a. 0• '. 3J3 c. SCR• d. J3J

158. A series +C circuit that is connected in parallel "ith an *C+ to eliminatefalse tri$$erin$.

• a. Cro"'ar b. Snubber

• c. Iaristor• d. Eliminator

1 9. A circuit that protects a sensiti(e circuit from a sudden increase insupply (olta$e.

a. Crowbar• '. *nu''er• c. Iaristor• d. Eliminator

1 1. A t"o-terminal 'idirectional thyristor.

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a. D7AC• '. *hoc/ley• c. +MAC• d. Diode

1 !. A DMAC is equi(alent to in(erse parallel com'ination of

a. Shockle$ io es• '. *chott/y• c. B• d. *C+Ls

1 &. A +MAC is equi(alent to in(erse parallel com'ination of

• a. *hoc/ley• '. *chott/y• c. B . SCR>s

1 ). Which are the three terminals of a +MAC?

a. 1ate; ano e* an ano e/• '. %ate source and sin/• c. Base emitter and collector• d. Emitter 'ase1 and 'ase!

1 5. Which de(ice can 'e modeled 'y a diode and t"o resistors?

• a. B• '. DMAC• c. *C+ . !"T

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1 . he minimum emitter to 'ase 1 (olta$e to tri$$er the 0 .

• a. or"ard 'rea/o(er (olta$e• '. ri$$er• c. Brea/do"n (olta$e . #eak voltage

1 4. he ratio of the emitter to 'ase1 resistance to the inter'ase resistanceof a 0 .

• a. Aspect ratio• '. Current $ain•

c. Iolta$e $ain . 7ntrinsic stan o3 ratio

1 7. or 0 it is the re$ion 'et"een the pea/ and (alley points.

• a. Acti(e re$ion b. Negative resistance region• c. ri$$er re$ion•

d. *aturation re$ion

1 8. ypical 'rea/o(er (olta$e of an *B*.

• a. ! I• '. ) I c. ? 4• d. 1 I

149. he tri$$er current is applied to theO

• a. Anode b. 1ate• c. Cathode

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• d. Base

141. he re$ion "here 'rea/o(er (olta$e of the *B* drops to 1 Iinstantaneously.

• a. alldo"n re$ion• '. all'ac/ re$ion c. Breakback region• d. Brea/do"n re$ion

14!. he ratio of +B1 and +BB is called

a. 7ntrinsic stan o3 ratio• '. +eu'erLs ratio• c. Common mode re ection ratio• d. CatLs ratio

14&. he time 'et"een the :rst application of electrode force and the :rstapplication of "eldin$ current.

a. S@uee e time• '. Weld time• c. old time• d. ,2 period

14). 3rocess "herein coalescence is produced 'y the heat o'tained from theresistance of the "or/piece to the o" of lo" (olta$e hi$h density electriccurrent in a circuit.

• a. or$e "eldin$ b. Resistance wel ing• c. 0ltrasonic "eldin$• d. PBW

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. #ressure applie

179. +esistance "eldin$ machine component that holds the "or/pieces.

• a. Electrical circuit• '. Electrode system c. echanical s$stem• d. Jone of the a'o(e

171. +esistance spot "eldin$ +*W@ machine type that is controlled 'yhydraulic cylinders.

• a. 6iniature "elders• '. +oc/er-arm "elder c. #ress-t$pe wel er• d. 3orta'le spot "elder

17!. 6achine component made up of the transformer and the currentre$ulator.

• a. Control system b. :lectrical s$stem• c. Electrode system• d. 6echanical system

17&. Welder machine "ith capacities up to 599 /Ia

• a. 6iniature "elders• '. +oc/er-arm "elder c. #ress-t$pe wel er• d. 3orta'le spot "elder

17). +e$ulates the time of the "eldin$ cycle.

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• a. Electrode• '. Current re$ulator c. Control s$stem• d. 6echanical system

175. Weldin$ machine use for lar$e "or/pieces.

• a. 6iniature "elders• '. +oc/er-arm "elder• c. 3ress-type "elder . #ortable spot wel er

17 . Another name for hammer "eldin$

• a. usion "eldin$• '. +W• c. 6aul "eldin$ . +orge wel ing

174. +eferred to as a locali;ed coalescence

a. el• '. 6old• c. Cast• d. 6etal

177. 3art of the "eldin$ electric circuit that is used to produce hi$hampera$e current at lo" (olta$es.

• a. Capacitor• '. Iolta$e re$ulator c. Transformer

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• d. he secondary circuit

178. he o(erlapped +*W.

a. RS: %Resistance Seam el ing&• '. ,+*W• c. ,*W• d. 0*W

189. *pot "eldin$ are most commonly used in

• a. *hips b. Automobiles• c. Airplanes• d. +afts

181. he last step in "eldin$ time control.

a. ,3 perio• '. Weld time• c. *quee;e time• d. old time

18!. he relati(e ma#imum "or/piece thic/ness "here spot "eldin$ can 'eused.

• a. 9.5 in

b. * in.• c. 1.5 in.• d. 9.!5 in.

18&. +esistance "eldin$ "as de(eloped 'y this man in and re(olutioni;ed the"eldin$ industry.

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• a. Msaac Asimo(• '. Qarel Cape/• c. homas *ee'ec/ . :lihu Thomson

18). he year "hen resistance "eldin$ "as disco(ered.

• a. 18&5• '. 1487 c. *??9• d. 18)5

185. Mt is the fusion or $ro"in$ of the materials 'ein$ to$ether.

• a. Coalition• '. Coincidence c. Coalescense• d. 6i#in$

18 . Arc "eldin$ requires a (olta$e around

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187. he 'ody structure of the car is "elded 'y

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• C. ne$ati(e feed'ac/• D. dopin$

!9&. he turn-o2 time of thyristor is &9 m sec at 59VC. Mts turn-o2 time at199V is

• A. same• B. 15 m sec C. 9( m sec• D. 199 m sec

!9). he pea/ and (alley currents of the 30 are typically

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• A. 9. 15&7 B. (.8?69*• C. !.• D. 9.71!5

!97. When *C+ starts conductin$ then

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C. TR7AC• D. *hoc/ley diode

!1!. he 0 operates in "hat re$ion after pea/ point?

• A. Cut o2 B. Negative resistance• C. *aturation• D. 3ositi(e resistance

!1&. What is 'asically a t"o-terminal parallel-in(erse com'ination ofsemiconductor layers that permits tri$$erin$ in either direction?

A. D7AC• B. +MAC• C. >0AD+AC• D. *hoc/ley Diode

!1). Which de(ice does not ha(e a $ate terminal?

• A. riac• B. *C+• C. E D. Diac

!15. he four-layer de(ices "ith a control mechanism are commonly referredto as

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• A. +e(erse 'rea/o(er (olta$e B. +orwar breakover voltage• C. oldin$ (olta$e• D. ri$$er (olta$e

!14. Mt is a three-terminal silicon diode "ith the a'ility to control a lar$e acpo"er "ith a small si$nal.

• A. +MAC• B. *C+ C. !"T• D. *C*

!17. he smallest amount of current that the cathode-anode can ha(e andstill sustain conduction of an *C+ is called theS

• A. ma#imum for"ard current• B. ma#imum for"ard $ate current• C. holdin$ current D. reverse gate leakage current

!18. Mt is the minimum additional current that can ma/e up for any missin$input $ate@ current in order to /eep the de(ice ,J.

• A. lea/a$e current• B. ac current• C. holdin$ current D. switching current

!!9. he 30 pro$ramma'le uni unction transistor@ is actually a type ofS

A. !"T th$ristor• B. E de(ice• C. +MAC• D. *C+

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C. *( ; /((( A; *?(( 4• D. !999 6W 19 A 1799 I

!! . An *C+ is a mem'er of "hat family?

• A. hyrector• B. hyratron C. Th$ristor• D. ransistor

!!4. Which of the follo"in$ can chan$e the an$le of conduction in *C+?

• A. Chan$in$ anode (olta$e B. Changing gate voltage• C. +e(erse 'iasin$ the $ate• D. Chan$in$ cathode (olta$e

!!7. What is the frequency ran$e of application of *C+s?

• A. A'out 19 / ; B. About 5( k• C. A'out !59 / ;• D. A'out 1 m ;

!!8. he minimum operatin$ (olta$e of the 0 is typically

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A. ouble-base• B. sin$le-'ased• C. a recti:er• D. a s"itchin$ diode

!&1. Mt is li/e a lo" current *C+ "ith t"o $ate terminals.

• A. 0• B. 30• C. *C+

D. SCS

!&!. What is the typical (alue of the re(erse resistance of *C+s?

• A. 1 to 19 • B. 199 to 1 /• C. 1 / to 59 / D. *(( kE or more

!&&. Which of the follo"in$ is the normal "ay to turn on a diac?

A. B$ breakover voltage• B. By $ate (olta$e• C. By $ate current• D. By anode current

!&). Mn a *C+ circuit the an$le of conduction can 'e chan$ed 'y chan$in$

• A. anode (olta$e• B. anode current• C. for"ard current ratin$ D. gate current

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!&5. he function of snu''er circuit connected across the *C+ is toS

A. Suppress dv/dt • B. Mncrease dv/dt • C. Decrease dv/dt • D. Decrease di/dt

!& . An *C+ is made of "hat material?

A. Silicon• B. Car'on• C. %ermanium• D. %allium-arsenide

!&4. he *C+ can e#ercise control o(er

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B. positive• C. at ;ero potential• D. at in:nite potential

!)9. Which of the follo"in$ de(ices has ha(e@ four layers of semiconductormaterials?

• A. *ilicon-controlled s"itch *C*@• B. %ate turn-o2 s"itch % ,@• C. Pi$ht-acti(ated silicon-controlled recti:er PA*C+@ D. All of the above

!)1. o" many pn unction does *C+s ha(e?

• A. "o• B. our C. Three• D. i(e

!)!. he silicon-controlled s"itch *C*@ is similar in construction to the

• A. triac.• B. diac. C. SCR.• D. )-layer diode.

!)&. Which of the follo"in$ de(ices has nearly the same turn-on time as

turn-o2 time?

• A. *C+ B. 1T,• C. *C*• D. PA*C+

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!)). Which of the follo"in$ is are@ the ad(anta$es of the *C* o(er acorrespondin$ *C+?

• A. +educed turn-o2 time•

B. Mncreased control and tri$$erin$ sensiti(ity• C. 6ore predicta'le :rin$ situation D. All of the above

!)5. An e2ect that reduces the possi'ility of accidental tri$$erin$ of the *C*.

• A. 6iller e2ect B. Rate e3ect•

C. End e2ect• D. ly"heel e2ect

!) . An *C+ "hose state is controlled 'y the li$ht fallin$ upon a siliconsemiconductor layer of the de(ice.

• A. *C*•

B. % ,• C. hyristor D. LASCR

!)4. 3o"er electronics deals "ith the control of ac po"er at "hat frequenciesessentially?

• A. !9 Q ;• B. 1999 Q ;• C. requencies less than 19 ; D. 9( fre@uenc$

!)7. o turn on the 0 the for"ard 'ias on emitter diode should 'e

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A. more than• B. less than• C. equal to• D. t"ice

!)8. What is the resistance of a certain )-layer diode in the for"ard-'loc/in$re$ion if I AQ 15I and M A 1 uA

• A. 15 • B. !1.!1 6 C. *5 E• D. 19. 1 6

!59. What is the pea/-point (olta$e for the 0 in pro'lem 4 if I BB 15I?• A. 19. 95• B. 5.4 81! C. 9.69H*5• D. 9.71!5

!51. he *C+ is turned-o2 "hen the anode current falls 'elo"

• A. for"ard current ratin$• B. 'rea/o(er (olta$e C. hol ing current• D. latchin$ current

!5!. When an *C+ is com'ined to a s"itch it is considered as a

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• A. li$htly• B. moderately C. heavil$• D. not

!5). An *C+ is a

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• D. *C*

!57. o turn o2 the *C+ "hich of the follo"in$ is done?

• A. +educe $ate (olta$e to ;ero• B. +e(erse 'ias the $ate C. Re uce ano e voltage to ero• D. +educe cathode (olta$e to ;ero

!58. Xour 'oss has as/ed you to recommend a thyristor that "ill ena'le youto turn it on with a pulse and also turn it of with a pulse . Which of thefollo"in$ should you recommend?

• A. an *C+

B. an SCS• C. a 30• D. a triac

! 9. he current from that semiconductor de(ice "hen it is re(ersed 'iased.

• A. ma#imum for"ard current• B. ma#imum for"ard $ate current•

C. holdin$ current D. leakage current

! 1. What is the ran$e of the turn-on times in hi$h-po"er *C+ de(ices?

A. 8( Is to *(( Is• B. 19 Zs to !5 Zs• C. 5 Zs to 7 Zs• D. 1 Zs to 5 Zs

! !. Xou need to desi$n a rela#ation oscillator circuit. he most li/ely de(iceto use mi$ht 'e

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• A. an *C+. B. a !"T.• C. a triac.• D. a )-layer diode.

! &. he

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! 4. Xou ha(e a li$ht-dimmer circuit usin$ an *C+. Mn testin$ the circuit you:nd that M % 9 mA and the li$ht is still on. Xou conclude that the trou'lemi$ht 'e one of the follo"in$S

• A. the *C+ is open.•

B. the s"itch is faulty.• C. the $ate circuit is shorted. D. this is normalJ nothing is wrong.

! 7. Which equation defines the intrinsic standoff ratio N@ of 0 s?

A. R B* K %RB* ) R B/ &• B. +B1 + B! @ = +B1• C. + B1 + B! @ = +B!• D. + B1 + B!

! 8. he (olta$e across an *C+ "hen it is turned on is a'out

• A. 9.5 I• B. 9.1 I C. * 4• D. 5 I

!49. he typical turn-o2 time of an *C+ is a'out

• A. !9 to )9 Hs B. 5 to 6( 0s• C. 1 to 5 Hs• D. 15 to !5 Hs

!41. Which of the follo"in$ de(ices has the smallest turn-o2 time?

• A. *C+

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B. 1T,• C. *C*• D. PA*C+

!4!. A triac is equi(alent to t"o *C+s

• A. in parallel B. in inverse-parallel• C. in series• D. in in(erse-series

!4&. Mt is the phase an$le relati(e to the po"er line at "hich point the $ate is

:red to commit the anode to conduct to the cathode

• A. ri$ht an$le• B. re(erse an$le C. con uction angle• D. :rin$ an$le

!4). Mt is the total resistance of the silicon 'ar from one end to another "ithemitter terminal open.

• A. $ate resistance• B. 'ase resistance• C. emitter resistance D. interbase resistance

!45. oldin$ current of a thyristor isS

•

A. Pess than latchin$ current B. ore than latching current• C. Equal to latchin$ current• D. Kero

!4 . An *C+ is a solid state equi(alent of "hich tu'e?

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• A. riode B. 1as-2lle trio e• C. 3entode• D. etrode

!44. What is the typical turn-on time of an *C+?

A. * 0s• B. 5 Hs• C. 19 Hs• D. & Hs

!47. An *C+ is a solid state equi(alent of "hich tu'e?

• A. riode B. 1as-2lle trio e• C. 3entode• D. etrode

!48. Mt is a special type of thyristor "hich is a hi$h-po"er semiconductorde(ice 'ut are fully controlla'le s"itches "hich can 'e turned on and o2 'ytheir third lead.

• A. 30• B. 6C• C. *C* D. 1T,

!79. When the temperature increases the inter-'ase resistance of a 0

• A. +emains unchan$ed B. 7ncreases• C. Decreases• D. is ;ero

http://en.wikipedia.org/wiki/Thyristorhttp://en.wikipedia.org/wiki/Thyristor

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!71. When chec/in$ a $ood *C+ or +MAC "ith an ohmmeter it "illS

A. show high resistance in both irections• B. sho" lo" resistance "ith positi(e on anode and ne$ati(e on

cathode and hi$h resistance "hen re(ersed• C. sho" hi$h resistance "ith ne$ati(e on anode and positi(e on

cathode and lo" resistance "hen re(ersed• D. sho" lo" resistance in 'oth directions

!7!. he 0 may 'e used as

•

A. an ampli:er• B. a recti:er C. a sawtooth generator• D. a multi(i'rator

!7&. A resistor connected across the $ate and cathode of an *C+ in a circuitincreases its

• A. dv/dt ratin$• B. oldin$ current C. Noise 7mmunit$• D. urn-o2 time

!7). AC po"er in a load can 'e controlled 'y connectin$

• A. t"o *C+s in series• B. t"o *C+s in parallel C. two SCRs in parallel opposition• D. t"o *C+s in series opposition

!75. An *C+ com'ines the feature of

A. a recti2er an resistance

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• B. a recti:er and capacitor• C. a recti:er and transistor• D. a recti:er and inductor

!7 . Mt is (olta$e-controlled fully controlla'le thyristor similar in operation"ith % , 'ut it has a (olta$e controlled insulated $ate.

• A. 30 B. CT• C. 0• D. 6%

!74. he three terminals of a triac are

• A. drain source $ate B. two main terminals an a gate terminal• C. cathode anode and $ate• D. anode source $ate

!77. A triac can pass a portion of

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• B. *C*• C. % ,• D. hyristor

!81. What %ree/ "ord "hich means Fs"itchG?

• A. +istor• B. rans C. Th$• D. hyristor

!8!. he

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• D. *C*

!85. An *C+ is made of silicon and not $ermanium 'ecause silicon.

• A. is ine#pensi(e B. has low leakage current• C. is mechanically stron$• D. is tetra(alent

!8 . he triac is fundamentally a=an

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• B. Ialley point• C. Any point 'et"een pea/ and (alley point• D. After the (alley point

&99. When the :rin$ an$le of *C+ is increased its output

A. ecreases• B. increases• C. remains unchan$ed• D. dou'les