TRC NGHIM CUI K K THUT O IN T

Cu 1 : Trong cc i lng sau y i lng no l i lng in tc ng l :

A . V , I , PB. V , I ,R

C . I , R, CD. P ,R, C .

Cu 2 : i lng in no sau y khng phi l i lng in tc ng :

A . VB. I

C. P D.R

Cu 3 : Trong cc i lng sau y i lng no l i lng in th ng l :

A . V , I , PB. V , I ,R

C . I , R, CD. R , L , C.

Cu 4 : Cc th t c sp xp no sau y ng vi qui nh ca cp chun ha trong o lng :

A . chun quc t , chun khu vc , chun quc gia , chun phng th nghim.

B . chun quc t , chun quc gia, chun khu vc , chun phng th nghim .

C . chun quc gia , chun quc t , chun khu vc , chun phng th nghim/

D . chun quc t , chun khu vc , chun phng th nghim , chun quc gia.

Cu 5 : c tnh tnh ca o lng bao gm cc loi no sau y :

A . chnh xc , phn gii , nhy , tnh tr , sai s ng.

B . chnh xc , phn gii , nhy , tuyn tnh ,tm ng vo ra.

C . chnh xc , phn gii , nhy , tnh tr .

D . Tc phn ng , tnh tr . sai s ng .

Cu 6 : c tnh ng ca o lng bao gm cc loi no sau y :

A . chnh xc , phn gii , nhy , tnh tr , sai s ng.

B . chnh xc , phn gii , nhy , tuyn tnh ,tm ng vo ra.

C . chnh xc , phn gii , nhy , tnh tr .

D . Tc phn ng , tnh tr . sai s ng .

Cu 7 : in p hai u in tr c tr s tin cy c l 50V . Dng vn k o c 49V. Sai s tuyt i l :

A . 1VB . -1V

C . 2VD. -2V

Cu 8 : in p hai u in tr c tr s tin cy c l 50V . Dng vn k o c 49V. Sai s tng i ca thit b l :

A . 1%B. 2%

C . 3%D. 4%

Cu 9 : in p hai u in tr c tr s tin cy c l 50V . Dng vn k o c 49V. chnh xc ca thit b o l :

A . 1%B. 2%

C . 98%D. 3%

Cu 10 : cho vn k c sai s tm o +5% tm o 100V . Gii hn sai s dng cho o in p 50V l :

A . 10%B. 20%

C . 30%D. 40%

Cu 11 : Trong qu trnh thc hin th nghim i vi cc thit b o , ngi s dng thit b o c sai , ghi nhm kt qu . thuc loi sai s no sau y :

A . sai s ch quanB. sai s h thng

C . sai s thit b oD. sai s ngu nhin.

Cu 12 : Sai s no sau y ph thuc thit bi o v nh hng mi trng bn ngoi :

A . sai s ch quanB. sai s h thng

C . sai s thit b oD. sai s ngu nhin.

Cu 13 : cc phn t thit b o c sai s do cng ngh ch to , s lo ha do s dng l :

A . sai s ch quanB. sai s h thng

C . sai s thit b oD. sai s ngu nhin

Cu 14 : Ga s in p c o bng mt vn k c cch khong 1 pht . mc d vn k hot ng bnh thng trong mi trng khng thay i, th tr s c ca vn k vn thay i cht t l do :

A . sai s ch quanB. sai s h thng

C . sai s thit b oD. sai s ngu nhin

Cu 15 : Vn k c sai s tm o tm o 300V. Gii hn sai s dng o in p 120V l :

A . 1% B.5%

C .10%D. 20%

Cu 16 : Vn k -Ampe-k c dng o cng sut tiu th ca in tr . c hai thit b ny u c sai s tm o 1% . Nu vn k c c tm o 150V c ch th 80V v ampe k c c tm o 100mA l 80Ma . Gii hn sai s tm o 80V l :

A . 1,5%B.1,86%

C . 1,7%D.2%

CU 17 : Vn k -Ampe-k c dng o cng sut tiu th ca in tr . c hai thit b ny u c sai s tm o 1% . Nu vn k c c tm o 150V c ch th 80V v ampe k c c tm o 100mA l 80Ma . Gii hn sai s ca cng sut o c

A . 3,29%B. 2.5%

C . 4,5%D. 6,34%

Cu 18 : Khi khng c l xo , cun dy trong c cu t in hot ng nh th no :

A . ng yn khng hot ngB. hot ng bnh thng

C . chy sau dng liD. kt hp chy v dng

Cu 19 : Trong c cu o t in , gc quay kim ch th t l vi :

A . tuyn tnh cng dng inB. tuyn tnh vi in p

C . bnh phng cng dng inD. bnh phng in p

Cu 20 : Trong c cu o in t , gc quay kim ch th t l cng dng in i vo khung quay . gi tr cng dng in l :

A . tr trung bnh

B . tr hiu dng

C . tr nh mc

D . dng in cc i

Cu 21 : Trong c cu o in t , gc quay kim ch th t l vi :

A . tuyn tnh cng dng inB. tuyn tnh vi in p

C . bnh phng cng dng inD. bnh phng in p

Cu 22 : S khc nhau trong nguyn l hot ng ca ng h ch th s v ch th kim l:

A . nguyn l in pB. nguyn l hin th kt qu

C . nguyn l dng inD. nguyn l o in tr

Cu 23 : u im no sau y khng phi ca c cu o t in :

A . chnh xc cao B. thang o c gc tuyn tnh

C . chu qu ti dng ttD. cng sut tiu th nh

Cu 24 : Trong cc c cu sau , c cu no c th o c dng in mt chiu :

A . c cu t inB. c cu in t

C . c cu in ng D. tt c 4 c cu trn

Cu 25: Trong cc c cu sau , c cu no c th o c dng in xoay chieu :

A . c cu t inB. c cu in t

C . c cu in ng D. c B & C.

Cu 26 : i vi c cu t in , khi dng in ng vo tng 2 ln th gc quay:

A . tng 2 lnB. gim 2 ln

C . tng 4 lnD. gim 4 ln

Cu 27 : m rng tm o dng DC trong c cu t in th cn phi :

A . Mc song song vi in tr shunt vi c cu o .

B . Thay i s vng dy ca cun dy .

C . Mc hn hp in tr shunt vi c cu o.

D . Mc ni tip vi in tr shunt vi c o

Cu 28 : m rng tm o dng DC trong c cu in t th cn phi :

A . Mc song song vi in tr shunt vi c cu o .

B . Thay i s vng dy ca cun dy .

C . Mc hn hp in tr shunt vi c cu o.

D . Mc ni tip vi in tr shunt vi c o

Cu 29 : Cho ampe-k DC kiu c cu t in nh hnh .

Vi Rm=1k , Imax = 50 , tm o 1mA th in tr shunt Rs c gi tr l :

A . 52,6 ohmB. 32,6 ohm

C . 23,57 ohmD. 34,49 ohm.

Cu 30: Mt ampe-k DC kiu c cu o t in c 3 in tr mc theo kiu shunt anyton . trong Imax ca c cu 50A , Rm =1k .Trong R1= 0,526 ohm ; R2 =4,737 ohm ; R3 =47,337 ohm.

Vy gi tr tm o ti B l :

A . 1 mA B. 10 ma

C .100maD.50ma

Cu 31 : Mt ampe-k kiu c cu o t in theo kiu shunt anyton . Trong Rm=1k ; Imax ca c cu 50A . cho 3 tm o : 1ma ; 10ma ; 100ma . Xc nh gi tr tm o l :

A . R1 = 0,526 ohm , R2 =4,737 ohm ; R3 = 47,337 ohm

B . R1 = 0,526 ohm , R2 =4,737 OHM ; R3 = 25,678 ohm

C . R1 = 0,526 ohm ; R2 = 47,337 ohm ; R3 =4,737 ohm

D. R1 = 47,337 ohm ; R2 =4,737 ohm; R3 = 25,678 ohm

Cu 32 : Cho c cu t in nh hnh v .

Cho ba tm o : 2,5V ; 10V ; 50V . Cho vn k dng c cu t in Imax =100A ; Rm =0,5k. Ga tr in tr 3 tm o tng ng l .

A . 24,5k ; 0,25k ; 35kB. 75k ; 24,5k; 0,5k

C . 24,5k ; 75k; 400kD. 75k ; 0,5k; 400k

Cu 33 : Cho ba in tr tm o tng ng l R1 =24,5k ; R2=75k; R3=400k l V1= 2,5V ; V2= 10V ; V3=50V . vn k dng c cu t in Imax = 100A ; Rm =0,5k.

Xc nh nhy ca vn k c gi tr l :

A . 10k/Vdc

B . 20k/Vdc

C . 30k/Vdc

D . 40k/Vdc

Cu 34 : Vn k dng c cu in t c cun dy c nh c dng Imax =50 ma tm o 0-300V . in tr ni Rm = 100 ohm . Cng sut ca in tr c gi tr :

A . 14,75 wB. 16,76W

C . 22,3 WD. 5,65W

Cu 35 : Cho s c cu in t nh hnh :

Rm = 1k ; Imax = 50A ; Xc nh gi tr R1 tm o Vac = 10V (RMS) vi Vd = 0,6(RMS).

A . 85kB. 100k

C . 120kD. 150k

Cu 36 : Cho s c cu in t nh hnh :

Rm = 1k ; Imax = 50A ; tm o Vac = 10V (RMS) vi Vd = 0,6(RMS).

Xc nh nhy ca vn k trong trng hp :

A . 9k.

B . 10k

C . 20k

D .30k

Cu 37 : cho s nh hnh v

Bit V =10V ; R2 =R1 =10k . Ga tr in p o c khi s dng vn-k c ni tr Rv = 200 k l :

A . 4,88VB.5V

C .5,55VD. 6,5V

Cu 38 : cho s nh hnh v

Bit V =10V ; R2 =R1 =10k . Ga tr in p o c khi s dng vn-k c ni tr Rv = 200 k l 4,88V . Sai s do nh hng ca vn k l :

A . 2,4%B. 3,2%

C . 4,8%D. 5,3%

Cu 39: Cho vn-k in t o p DC c h s khuch i =1 nh hnh v:

Cho cc tm o : 1V ; 10V ; 50V ; 100V . Dng in chy qua c cu Imax = 100 ; Rm =1k . gi tr in tr ca tm o R1 l :

A . 900k

B . 10k

C . 80k

D . 50k

Cu 40 : Cho vn-k in t o p DC nh hnh v :

Cho cc tm o : 1V ; 10V ; 50V ; 100V . Dng in chy qua c cu Imax = 100 ; Rm =1k . gi tr in p V0 l :

A . 1V

B . 10V

C . 50V

D . 100V

Cu 41 : Cho vn-k in t o p DC nh hnh v :

Cho Vi = 0,1V ; R1 = 90k ; R2 = 10k ; Rm =1k ; Imax = 50A .

Xc nh Rs Im qua ng h ch cc i :

A . 10kB. 19k

C . 20kD. 18k

Cu 42 : Cho vn-k in t o p DC nh hnh v :

Cho Vi = 0,1V ; R1 = 90k ; R2 = 10k ; Rm =1k ; Imax = 50A .

Xc nh gi tr in p Vo ca vn k l :

A . 1V B. 2V

C . 3VD. 4V

Cu 43: Cho vn k o in p DC dng omp IC nh hnh v :

Cho Vi = 0,1V , Imax = 50A ; Rm =1k . Xc nh gi tr R1 l :

A . 1 kB. 2k

C . 3kD. 4k

Cu 44 : Cho vn k o in p DC dng omp IC nh hnh v :

Cho Vi = 0,1V , Imax = 50A ; Rm =1k , Rs = 2k . Ga tr in p Vo l :

A . 250V B .500V

C . 100VD. 300V

Cu 45 : cho kf = 1,5 ; Imax = 2A . gi tr hiu dng thc ca vn-k ny l :

A . 2,7 AB. 6,2 A

C . 3,4 AD. 5,9 A

Cu 46 : Mt ampe-k dng c cu o t in c in tr c cu o Rm = 99 v dng lm lch ti a Imax =0,1ma . in tr Shunt c Rs = 1 ohm . Xc nh gi tr dng in tng cng i qua Dm .

A . 10ma

B . 5ma

C . 2,5ma

D . 15 ma

Cu 47 : Mt c cu o t in c I = 100A , in tr ni khung quay R=1k . Ga tr in tr shunt mc vo c cu o tr thnh mt ampe-k tng ng vi tm o 100ma l :

A . 1 ohmB. 2 ohm

C . 0,1 ohm D. 0,2 ohm.

Cu 48 :

A . 10ma ; 100ma ; 1A B. 10ma ; 1A ; 5A

C . 1A ; 100ma ; 3AD. 1A ; 10ma ; 1A

Cu 49 : Cho c cu o t in Imax = 100A , in tr ni Rm = 1k c dng lm vn k DC . Tnh in tr tm o vn k c Vtd =100V .

A . 999k

B . 788k

C . 1100k

D . 1200k

Cu 50 : : Cho c cu o t in Imax = 100A , in tr ni Rm = 1k c dng lm vn k DC , in tr tm o vn k c Vtd =100V l 999k . Xc nh gi tr in p hai u vn-k khi kim ch th c lch 0,5Dm l :

A . 50V

B . 75V

C .100V

D . 25V

CU 51 : Mt Vn k c tm o 5V , c mc vo mch

o in p hai u in tr R2 nh hnh v .

Ga tr in p VR2 khi cha c vn k l :

A . 10V B.5V

C .15VD.20V

CU 52 : Mt Vn k c tm o 5V , c mc vo mch

o in p hai u in tr R2 nh hnh v .

Ga tr in p VR2 khi c vn k ,c nhy l

L 20k/V. :

A . 3,87VB. 4,89V

C. 2,53VD. 6,56V

CU 53 : Gi tr in p hai u c cu o t in c Rm = 850 v Ifs = 100A khi kim lch ti a l :

A . 85mV B. 100 mV

C . 125 mVD. 200 mV

CU 54 : Mt c cu o t in c Ifs =1ma v in tr dy qun Rm =500 ohm kt hp mch chnh lu bn k tr thnh vn k AC . nhy vn k AC l :

A . 450/VB. 900/V

C . 1000/VD. 200/V

CU 55 : Mt c cu o t in c Ifs =1ma v in tr dy qun Rm =500 ohm kt hp mch chnh lu bn k tr thnh vn k AC . Xc nh gi tr in tr tm o vn-k c Vtd = 30V l :

A . 13k

B . 18k

C . 21k

D . 5k

Cu 56: Mt c cu o t in c Ifs =200A v in tr dy qun Rm =500 ohm kt hp mch chnh lu ton k tr thnh vn k AC . Xc nh gi tr in tr tm o vn-k c Vtd = 50V l :

A . 133,9k

B . 224,4k

C . 211,2k

D . 578,5k

Cu 57 : u im ca o dng/p dng phng php nhit in c in so vi phng php chnh lu l :

A . n gin , r tin

B . khng b nh hng ca mi trng

C . c th o tn hiu c dng xung bt k

D . Hot ng n nh.

Cu 58 : Nguyn l o dng DC trong ampe k in t l :

A . Chuyn dng cn o thnh in p cho php

B . Thay i s vng dy trong mch

C . to ra dng in cc mnh trong in p

D . phn chia in p thnh cc in p nh.

Cu 59 : Cho mch nh hnh v sau :

Vn-k c nhy 10k ch 500V v ampe- k ch 0,5A c RA =10 . Vn k t tm o 1000V . Ga tr in tr ca Rx l :

A . 990B. 1000

C . 1350D. 2000

CU 60 : Cho Eb =1,5V ; Imax =100A ; R1+Rm = 15k. Xc nh ch th ca kim khi Rx =0 v s ch th s in tr khi Im =1/2 thang o l :

A . 15000ohm

B . 25000ohm

C . 10000ohm

D . 32000ohm

Cu 61 : Cho s mch o in tr bng ohm-k nh hnh v :

Cho Eb = 1,5V ; R1 =15k ; Rm =1k ; R2 = 1k ; Imax = 50A . Xc nh gi tr ca Rx khi 3/4 thang o l :

A . 5kB. 10k

C . 15kD . 20k

Cu 62 : Bit Eb = 1,3V ; ; R1 =15k ; Rm =50 ; Ifs = 50A .

Ga tr R2 mi l :

A . 35,75 ohm B. 68,18 ohm

C . 45,76 ohmD . 98,4 ohm .

Cu 63 : Bit Eb = 1,3V ; ; R1 =15k ; Rm =50 ;Ifs = 50A .

Ga tr Rx bao nhiu khi tr ch th thang o .

A . 5k

B . 10k

C . 15k

D . 20k

Cu 64 : Cho s dng cu wheatstone cn bng nh hnh v :

Cu pht biu no sau y ng cho trng hp trn :

A . Dng in qua in k khng thay i

B . VP = VR

C . R =S

D. VR =VP

CU 65 : u im ca php o in tr dng cu Wheatstone cn bng l :

A . khng ph thuc vo ngun cung cp E v ph thuc vo nhy ca in k

B . Ph thuc vo dong in tr ni

C . ph thuc hon ton vo nhy ca in k

D . to s cn bng tt cho in tr

Cu 66 : Cho sai s ca S l ; P ,Q l 1% . Sai s ca R l :

A . 0,5%B. 1%

C . 1,5%D. 2,5%

Cu 67 : Cho wheatstone cn bng nh hnh v :

Cho P = 1W ; Q = 10W ; S =237,5 ohm. Khi cu cn bng , gi tr R l:

A . 23,75

B . 2375

C . 2,375

D . 0,2375

Cu 68 : Cho s o in tr dng cu Wheatstone khng cn bng nh hnh v :

Tng tr ng ra ca cu xc nh theo cng thc l :

A . r = [P // R] +[Q // S]B. r =[P //Q] + [R//S]

C . r = [P // S]+[Q // R]D. r = [P+R] //[ Q+S]

CU 69 : Cho s o in tr dng cu Wheatstone khng cn bng nh hnh v :

Dng in chy qua in k khi cu khng cn bng :

A . Ig = B . Ig =

C . Ig = D . Ig =

Cu 70* : Cho ohm k thng c chnh , c ngun cp l 5V , in tr chun tm o R1 = 50k , s dng c cu ch th t in c R2 = Rm = 1 k , dng ti a qua c cu ch th l 50A . Gc quay kim ch th v tr qc quay ln nht .

in tr cn o c gi tr l bao nhiu :

A . 50K *

B . 100K

C . 150K

D . 200K

CU 71 : Loi no di y dng o in tr c gi tr nh l :

A . Cu Wheatstone cn bng

B . cu Wheatstone khng cn bng.

C . cu i KelVin .

D . Vn k v microampe-k

Cu 72 : o in tr trong V.O.M in t c ghi R00 tr s c trn mt ch th l 36 th c kt qu o nh th no l ng nht :

A . 3600

B . 360

C . 36

D . 0,036

Cu 73 : cho mch o nh hnh v sau :

Dng in chy qua c cu o kim ch th ca Ohm-k khi s dng tm o R trong trng hp Rx =0 l :

A . 622,4

B . 534,8A

C . 783,9A

D . 845,6A

CU 74 : Ta o in tr bng phng php V v A c mc r di . Ampe-k ch 0,5A , vn-k ch 500V . Ampe-k c Ra = 10 , vn k s dng tm o 1000V v c nhy l 10k/v . Tnh tr gi ca R l :

A . 500 ohm

B . 700 ohm

C . 990ohm

D . 1000 ohm

Cu 75 : Mt Ohm-k ni tip c cc thnh phn sau : ngun cung cp Eb =3V , in tr ni tip R1 = 30k , in tr shunt R2 = 50 ohm , c cu o c Ifs = 50 , in tr c c cu o Rm = 50 ohm .

Ga tr Rx o c tng ng vi lch FSD l :

A . 75k

B . 100k

C . 90k

D . 110k

Cu 76 : Ga s ohm-k cu 75 c Eb gim xung cn 2,5V . xc nh li gi tr R2 mi cn iu chnh l :

A . 50 ohmB. 100ohm

C . 75,2 ohmD. 45,8 ohm .

Cu 77 : o in dung bng vn k , ampe k , watl-k cho nh hnh v :

Gi tr in dung tnh theo cng thc no sau y :

A . CX = B. CX =

C . CX = D. CX =

Cu 78 : o in dung v in cm dng Wheatstone xoay chiu cn bng nh hnh v sau :

iu kin cn bng no sau y l chnh xc nht trong qu trnh cn bng :

A . B. Re =Re

C. Z1.Z4=Z2.Z3D.

CU 79 : Cu o in dung mc theo s hnh sau :

Ga tr in dung khi cu cn bng xc nh theo cng thc :

A . CX = B. CX =

C . CX = R3R4C1 D. CX = 0.

Cu 80 : H s tn hao ca t in c tr s nh mch tng ng c tnh theo cng thc sau :

A . Rx/CXB. RXCX

C . 1/CxRxD. CX/RX

CU 81 : : H s tn hao ca t in c tr s ln mch tng ng c tnh theo cng thc sau :

A . Rx/CxB. RXCX

C . 1/CXRXD. WCX/RX

Cu 82 : H s phm cht ca cun dy c tr s nh mch tng ng c tnh theo cng thc sau :

A . LX/RXB. RX/LX

C . LXRXD. 1/RXLX

CU 83 : H s phm cht ca cun dy c tr s ln mch tng ng c tnh theo cng thc sau :

A . RXLXB. LX/RX

C . LXRXD. 1/RXLX

CU 84 : Cho cu ph qut o in dung nh hnh v l :

Cng thc tnh gi tr Cx l :

A . CX = B. CX =

C . CX = 1/R3R4C1D. R3R4C1

CU 85 : Cho cu ph qut o in dung nh hnh v l :

Ga tr h s tn hao D l :

A . D = C1R1 B . D = CXRX

C . D = 1/C1R1 D. D = C1/R1

CU 86 : Cho nh hnh v sau :

C1 = 0,1A; R3 = 10k . iu chnh R1 = 125 ohm ; R4 = 14,7 kohm th cu cn bng xc nh gi tr tn hao D l :

A . 0,008D. 0,001

B . 0,16C. 0,0032

CU 87 : cho cu ph qut o in cm nh hnh v :

Ga tr Lx cn tm l :

A . C3R1R4

B . C3R1/R4

C. 1/C3R1R4

D . R1R4/C3

CU 88 : cho cu ph qut o in cm nh hnh v :

GI tr h s phm cht ca cun dy l :

A . C3R3B. 1/R3C3

C .C3/R3D. R3/C3

CU 89 : Trong cu Maxwell nh hnh v trn , in dung mu C3 = 0,1F , tn s tn hiu cung cp cho cu f=100Hz . Khi cu cn bng R1 = 1,26k ; R3 =470 ohm ; R4 = 500 ohm . Ga tr h s in cm

A . 63mhB. 126mh

C. 50mhD. 75mh.

Cu 90 : Trong cu Maxwell nh hnh v trn , in dung mu C3 = 0,1F , tn s tn hiu cung cp cho cu f=100Hz . Khi cu cn bng R1 = 1,26k ; R3 =470 ohm ; R4 = 500 ohm . Ga tr h s phm cht ca cun dy l :

A . 1578

B . 29540 x

C . 35882x

D . 10892x

Cu 91 : Cho cu o in dung nh hnh v sau :

Cho C1 = 0,1A ; R3 = 10k . Bit rng cu cn bng khi ngun cung cp c f= 100Hz ;

R1=125ohm v R4=14,7k. Ga tr in dung ca cu l :

A . 0,068

B. 0,15F

C . 0,098F

D.0,01F

CU 92 : Cho cu o in dung nh hnh sau :

Bit thnh phn mu c C1=0,1F; R3=10k. Cu cn bng khi ngun cung cp c f=100Hz ; R1=375 ohm ;R4= 14,7k. Gi tr h s tn hao ca t l :

A . 42,5

B . 45,8

C . 58,8

D . 22.4

Cu 93 : Cu Maxwell o in cm nh hnh v sau :

C3 =0,1F ; ngun cung cp c tn s f=100Hz . Cu cn bng khi R1=1,26k ; R3=470 v R4=500.

H s phm cht l

A . 0,03

B . 1,21

C . 0,08

D . 2,35

Cu 94 : Cho hnh v cu Hay sau :

C ngun cung cp f=100Hz cn bng khi C3=0,1F ; R1=1,26k, R3=75 ; R4=500.

H s phm cht ca cun dy l :

A . 212

B . 257

C . 435

D . 200

Cu 95 : Tnh thnh phn tng ng ca Ls ca cun dy c Lp = 63mh ; Rp=8,4k , c tn s f=100Hz.

A .