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习题练习:Physics Unit21: Electromagnetic Induction & Faraday's Law



 作者: admin   总分: 142分  得分: _____________

答题人: 匿名未登录  开始时间: 22年08月20日 21:29  切换到: 整卷模式

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1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following ar*zidcje cx (66e units of magnetic flux except

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction statese(lce98hxx t; that the $emf$ induced in a loop of wire is proportional to

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3#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the number of loops of i8tnun2 -rkw* wire in a coil produces what kind of change on the i n*uk8n2 twr-induced $emf$, assuming all other factors remain constant?

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4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the strength of the magnetic field through a loop of wire produces whaw1,utb84 saz8- eajg dg7ra 9ft kind of change on t-z8a, 8 g71rjbgdw a uf4tes9ahe induced $emf$, assuming all other factors remain constant?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the diameter of a loop of wire produces what kind of change on the indrspz(9 5aalm ywebzap /1516 quce ewp 5zal/sa 96pm(rz5bqy11ad $emf$, assuming all other factors remain constant?

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6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As a coil is removed froo)8emeli 99 bmm a magnetic field an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's law, the directi crgfdu6 9hu-bo4*u7ion of an induced current in a conductor will be that which tends to produce which obcughrf7946u-i*dou f the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal t;w2va(q67p gnf ml(+s pys ;rsable. A bar magnet is held above its center with its north pole pointing down. The stationary mam y s6vrwa+sp((;;qnpf 7 2gslgnet induces (when viewed from above)

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizockjkv 5y b7+vz3)k s*mkviqv 9hk79i,ntal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approav7*bk k)q+k9kvivmj5s39cih v7 yk,zches the coil, the falling magnet induces (when viewed from above)

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10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a table u refvia49 0;ktop in a region where the magnetic field vector points sie 0; vau9rkf4traight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top in akp qsf:fvg;,. region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the induced current in ,svkf p :;qgf.this coil as the field increases?

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12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a horizontal table top 1)ws zc,etr-bgz 8 .cwin a region where the magnetic field points straight down. The magnet1ztcg8 -.ceb z)wws,ric field disappears suddenly. When viewed from above, what is the direction of the induced current in this coil as the field disappears?

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A long straight wire lies on a horizontal table and carries an evervn qhlge8l aywb1ulksg+/.2w 2jr973 -increasing current northward. Two coils of wire lie flawsrn21 7jh l8vk9 uy+l geq2/ l3b.wgat on the table, one on either side of the wire. When viewed from above, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls through a loop of wire with the 1 73t-p gvg d jxo:j;-s3daihunorth pole entering first. As the north pole enters the wire, the induced current will be (as viewed fr-gt3di d u-7v1psa3 jhjxo ;g:om above)

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angula8 xq*p+r4pybjfj;g /o2 r0-2 daftr ttr speed about an axis whose dir0- p pjf 8t2xartrr/+y;gj4q2 odtb*fection can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be zero?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotatedh//nq 2h 2jlwq at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the o2/2qhjl n/q whrientation of the loop's axis of rotation if the induced $emf$ is to be a maximum?

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17#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Faraday's law.:aio 3-ms uzo)
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18#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Lenz's law.
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19#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
List the three ways ,m hal eksk62)that an $emf$ can be induced in a loop of wire.
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20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A wire moves across a mag310a8 z bej:p.h)erlgtx hjb9netic field. The $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved-*3qv/(bx tfke*pldb northward at constant velocity through a magnetic field that points straight down. Make a statement concernin3t(k-xp d*f b/ *vlbeqg the potential induced across the rod.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar rotates at a constant angular vnf ygy 75ead5h9(jn ;xc;bd x(elocity $\omega$ about a vertical axis through one of its ends while in a constant magnetic field B that is directed down. The $emf$ induced between the two ends of the bar is

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23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An electric generator fkcp ei txxg97a-k )6 sf1h/2mtransforms

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24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator coil rotatduq ; 1y3it2gsj6) *uht6eush es through 60 revolutions each second. The frequency of the ;y26 3tguh)u t*ud 6sijsq1he$emf$ is

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25#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A transformer is a devicebc,-r 5p 3zefi used to

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26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A transformer is a device -ot.ic; er-: 6v ebny*mtjor5that

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27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the second+h0zv )vfv uf/ary coil contains more loops than the primary coil then it ifu /+zvfhv) 0vs a

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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the primary coil co ;75 pdhsgt+te pmgkz5cfw8;0 qba4l, ntains more loops than the secondary coil then it is a 47k scplamedb,0qt 8; g; +zhpw5gt5f

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29#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, the powez gg3kn bj-2i 3f.2zlcr input

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30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a given LC resonant circuit,u;wbikr;.v 5dtcy+, j

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to an ideal b3dnk4 5vngfa0attery of constant terminal voltage. At the0fg4nvad5 n 3k moment contact is made with the battery, the voltage across the resistor is

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to an ideal batter4hh3pooop7 .m y of constant terminal voltage. At the moment contact is made with the bato4ohphpm 3 7.otery, the voltage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit wift 79(e;m,p-g lgmyvath inductance L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the inductance is 2L. When it is connected to the same $emf$, what will be the final value of the current?

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is connected txd-ik px)2(0h/ zggygfk/ v*xo an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a bat;hpz lfwr(:o oeyr 4layf3755 tery. The time constant for the circui3ef74l ;y5arfy5 pzorol(:h wt represents the time required for the current to reach

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series 79 rxji.vl et8to a battery. The battery is suddenly removed from the circuit. The time constant for of the circuit repr.tl ej9r ix7v8esents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the same units ui+du+5d0lbt except:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connected to an AC power suppl* c w oczvm9c;-h g)5gh-cljz0g,vwt(,y tz9ny. On this circuit, the current

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure inductor is connected to an AC power su4haw eb, oe9-)xq qe+ipply. In this circuit, the currena4 w ,)ebxeh+i- qeo9qt

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40#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The inductive reactance in an ac circuit changes by what fach gpcgmt/m(.om ; a(/sy6d.jq tor when the frequency is 6mc hadpq;o/ s(/t g( y.gmj.mtripled?

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41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the frequency of the AC voltage across an inductor is doubled, the inducti:) 4japid1x y n8g,epgve reactance of th1, 8g iey)xnd4p:jag pat inductor

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across an inductor approaches ze,mb gpsgyx08 (ro, the inductive reactance of thym8 ,(bg gpsx0at coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In this circui+usnbp p+r0( st, the curreprspu 0sb(+n +nt

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance in an ac circuit changes by what fe pmbgskqz lhz5 xg6x5 fh771s6 6c4:sactor when the frequency is tripled?1 467 qscxzfp76xz e 5:ks b6gghhl5sm

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across a capacitor approaches zero,sti.tnklu yc oc:1. fj9 2:xbo:g /tz, the capacitive reactance o tf:otsxizbgy1:.c .kto:l,/u2c n9 jf that capacitor

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46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle between the voltages of the inductor and capacitor 7wtx+z-mb7,ra u wh6jin a RLC series circu, 7jzmht b+xu 67r-wwait?

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47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The power factor of an 7fvfg,a mn20m) p ah)lRLC circuit is defined as $\cos M = R/Z$, but the phase angle can also be calculated from .

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48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the circuit increases if R increase73.m km5cvl 3u3piukgnzxq n; 3i9xu6s. When is this statemecum97l3ixun i63 5. k m3k;uvz 3nxgqpnt true?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the cirzvqws9rg9 bal(: -*s 9ykcc*ycuit increases if $X_L$ increases. When is this statement true?

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50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC series bu m t;m:;mqj5circuit. The impedance of the circuit increases if $X_C$ increases. When is this statement true?

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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the inductance and tof2 ;ht+1vpj jxf 7vx2he capacitance both double in an LRC series circuit, the resonant f 2vp;+vx1t2fo x7hjj frequency of that circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is driven by an AC applied jlui3q( q r qn.;)ri8)ws.tnqvoltage. At resonance,

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Resonance in a series RLC circuit y w3iuc 6qx;9w x7ud8voccurs when

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54#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A flux of $4.0 \times 10^{-5} \; Wb$ is maintained through a coil for 0.50 s. What $emf$ is induced in this coil by this flux?

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic fiel, y;eawe35ac od of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are parcoe5ae3 ywa ,;allel.

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic field of.w8 vm nzq)a3a 0.20 T. Fin8a3nqzm vw)a.d the magnetic flux through the loop when the plane of the loop and the magnetic field vector are perpendicular.

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57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is yxvg gsr3j2- +2l0nygrotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vec 302yxjgv2gry l+gn s-tor are at an angle of $30^{\circ}$.

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional area of an adjustable single loop is reduced fwrsb9i pvu);r q ,c/j*h/oob 4rom $1.0 \; m^{2}$ to $0.50 \; m^{2}$ in 0.10
s. What is the average $emf$ that is induced in this coil if it is in a region where B = 2.0 T upward, and the coil's plane is perpendicular to B?

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59#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The flux through a coil changes from klmb(qd:sw .7 $4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a square frame with sides 18e5bh:x*biya:w) rk; y cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the 5b e ;:rakby*ihy:x w)average value of the induced $emf$.

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61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A square coil of wire with 15 turns and an arf b jraeo43a::drn:: xea of $0.40 \; m^{2}$ is placed parallel to a magnetic field of 0.75 T. The coil is flipped so its plane is perpendicular to the magnetic field in 0.050 s. What is the magnitude of the average induced $emf$?

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62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil of 160 turns dgg7b6hqd.cetl0 2 v(and area $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span of 60 m flies hogtyr9n. cpd 17rizontally at a location where the downward component of the Earth's magnetiyd7.tr1 gc9 pnc field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar that is 2.0 m long rotates at a constant angular velocit3n2tzih7g,j+ ls yl6r96gew ky 6 tgwgrs 9li+,zlj6nk723yeh of 2.0 rad/s about a vertical axis through one of its ends while in a constant magnetic field of $5.0 \times 10^{-5} \; T$. If the magnetic field vector points straight down, what $emf$ is induced between the two ends of the bar?

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65#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The coil of a generator has 50 loops andmwd8z6s 2g s.z6gui/ o a cross-sectional area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consw(/3 onjn9z tcists of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 re8fd2/tbqcscm8ihpg to)m*iu .:l s, /ctangular loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular to the axis of rotation, what will be the maximum output v2/ms q* li)/df.8t8, chtbpm:uc sog ioltage of this generator?

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68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turhk( ;ok44id.h wbnogncx ),1b ns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced current.

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that you wish to construct a simple1 xg 8i tpw,rrw66;8cy-h siup AC generator with an output of 12 V maximum when rotated at 60 wpw6-6, 8srh1pr gtiu;y 8cxiHz. A magnetic field of 0.050 T is available. If the area of the rotating coil is $100 \; cm^{2}$, how many turns are needed?

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70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are designing a generator with a maximum /u):puyte6as1c6ogl$emf$ of 8.0 V. If the generator coil has 200 turns and a cross-sectional area of $0.030 \; m^{2}$, what would be the frequency of the generator in a magnetic field of 0.030 T?

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71#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have a resistance of 6.00 W. The /-* dy) yy4 waww:jflwmotor operates on $120 \; V$ AC, and when running at full speed it generates a back $emf$ of 105 V. What is the starting current of the motor?

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72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor havh ci1a l)61+safp elv*e a resistance of 6.00 W. The motor operates on 120 V AC, and when running at full speed it generates a)ipaf as+h1 *6ev c1ll back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 2 ; h,h. *eog5h;oeiybk4-V power supply. The operating current is 1.0 A. What is toe. 5;khh ;ygoh,* iebhe start-up current?

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74#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V power supply)0poboiuv3vi1(t w t4us- tj7. The operating current is 1.0 A i ipwo -suu) vtv374jott10 b(at full speed. What is the back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is - a2mesjnbj0e, ,vxo, connected to a 24-V power supply. The operating current is 1.bnos2jae ,x,e- ,v0j m0 A at full speed. What is the back $emf$ when the motor is running at half speed?

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76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A step-down transformer is needed to reduce a primary volta 6x1j2tro3 bihge of $120 \; V$ AC to $6.0 \; V$ AC. What turns ratio is required?

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77#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  2.0 A in the 100-turn primary of a transformer causes 14 A t/oy/ui8fbnvs;e2g:ct/ a+g4nydl8d fd .tp 0o flow in the secondary. How mtdocu: .if/4 s lnty2g0g8d8n;ayv/+epd /b fany turns are in the secondary?

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78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, how many turns are necessary in a 110-2hio/ c sz i*z9s,pib1V primary if the 24-V secondary has 100 turobzic 2/i 1,9 psh*izsns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consists of a 500-turn prima)qntwnav6n/ wpgu29vjr5: :r ry coil and a 2000-turn secondary coil. If the current in the secondary is 3.npr)2 jn5 v:n/wga:qw69uvt r0 A, what is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primary of a transformer. Assuming 100% /;geui;qec957 8sm8xe )j/v yle aig uefficiency, how many amps at 24 V can flow ju sgel/mxi)ugv8iqe5 ee 7 ;c8;y9/ain the secondary?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The secondary coil of a neon sign transformer provides 7500 V a)uks cw+evv, gn9k2/it 10.0 mA. The primary coil operates on 120 V. What do) +v/g29se kuvk wc,nies the primary draw?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its pri /g5rbfcyp )yep/wsa u 1+i9c.7kigs /mary coil and 300 turns on its secondary coil. If 120ac iy/ i)/sukpw cy5p/ .re 7gsgfb+19 V at 2.0 A is applied to the primary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its prim5g51dx e0 b jfl8kyp+dary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is adex+p5f 5y0 jgbdl18kpplied to the primary, what current is present in the secondary?

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84#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary1i-o)+bfkzyr/ (gsyb has 200 turns. If the input current at the primary is 100 A, ygfb/siyr) bo(z k1+- we can expect the output current at the secondary to be

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 tyaiv,84 daet 7urns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we a4t7yi ve 8a,dcan expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary ha2b4n zewi,sj gwd1k ;e;qv,a4 s 200 turns. If the power input to the primary is 100 W, we can expect the power output of the secondary to be (nen jew; q2a i,,b;4sk4zvwgd1eglecting frictional losses)

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87#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usualld wxjmy3lmil6+ c9i3+(+(mexj 96rrks h/ vdqy stepped up to rsx( /9c(ll9 xqidm 66hmrdmik3j3+ w+y+ejv 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The :),h/k5cum5nv6fnclwb j)mo voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of to)om ,5/:v)6wc5 cjnbu fmknl htal resistance 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 12wbvhoj i7 g7/m74gsc20 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the 7i4gjmsbc 72 hwgo7v /percentage power lost in the transmission line if the voltage is not stepped up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long h xjp.t0v-6tij:(ov 88xrggo qh6soe+ as a total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy would be lost if th06o+8vig:. ( o8htsj -v pjrg xe6oxqte transformer were not used?

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91#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a total resistance of 0.60 W. y3lvg p y*wjx,s/k7)f A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio ofv/ w*x7p,lyj3g ykf )s 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W line at 1000 V. How much less power w1m j:h /b3sumaould be lost if the power were trammbas:h /u1j3 nsmitted at 3000 V instead of at 1000 V?

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93#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The output of a generator is 440 V at 20 A. It (:*x0 n0zdkhma xit;6+ jkbsmis to be transmitted on a line with res*xd k0ixm;j 0 batnk+hm: s6(zistance of 0.60 W. To what voltage must the generator output be stepped up with a transformer if the power loss in transmission is not to exceed 0.010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. How much energy is stored in theo,z) kg u+6e7kq 1kigx coil's makego)6g 1ku, qx+kzi7gnetic field?

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95#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A simple RL circuit contains a 6.0-W resistor and an 18-H inductor. What is i )q2rn(b:gkb this circuit'(k:)2 bqr bnigs time constant?

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96#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the peak voltage in an AC circuit where tlg*ji/kjc.l, vyl *( h2xt:yfhe rms voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What is th1 5oglltb6 (syb* bq1be peak current?

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98#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC ou;a8ojyhd iq3 7tlet. What is the resistance of the lamjqhio;y783 da p?

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99#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to dr6ojhnfq* os;4q5: aa 120-V ac power supply. What is the peak current through ;f5oajsd*4 h:qr6oqn the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. What is the power yrk /nmxgw5. e;;xbip /0mqq7dissipatp yxeg q;x/rm/5nki;70bq.m wed in the resistor?

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101#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor2vejc:(y + xwb is $I = 0.80 \sin (240 t)$. What is the rms current?

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102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through r.q9n yvj(r*ia 50-W resistor is $I = 0.80 \sin (240 t)$. At what frequency does the current vary?

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103#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor is (levmv-0 w+p8svay. bg)ad6 m$I = 0.80 \sin (240 t)$. How much power on average is dissipated in the resistor?

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104#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the reactance of a 1.0-ja-mzh kz3y7) mH inductor at 60 Hz?

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105#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the inductive reactance of a 2-fv/ .k.k dpkkuzy(ei5 f98qs .50-mH coil at 1000 Hz?

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106#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will a 14.0-mH coil have ;q8;mjb ths2h 14.0 W of inductive reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 157 W o*2da0 do*njrwch8o ;tf inductive reactance at 1000 Hz?

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108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH inductor when 120 V AC at a frequency of 20irof )6t2djwl(cln-) kHz is)nr6l wf2lj( id) o-ct applied to it?

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109#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 2.50-mH ,c2dbf9i s cbk61x od9coil due to a 110-V, 60.0 Hz source?

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110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitive reas8 ii2ajz -1i: lxwz-pzim* x/ctance of a 4.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is needed to have 50 W of capacitive reactanc,jc )7lk-w j:mly+pwwe at 10 kHz?

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112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacicep ,-d*y-xy5 g0thwqtor have a reactance of 1200 W?

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113#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will the capacitive reactance of j30usidjv 0lw-4bk /o*six*x a 0.010-mF capacitor be 100 Wudwsv-*l0 sjio4 bk*x /ix3j0 ?

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114#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current througrjqyo/hg ikjpz h7a )ld)/ju6q:1q ,l a;1 dx7h a 0.0010-mF capacitor at 1000 Hz and 5.0 V?

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115#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the impedance of an ac seifuhhkb x70f cji1) srz6,q )*ries circuit with 12.0 W resistance, 15.0 W inductive reactance, and ,h1 s cff)urb 0*i7)h6qizxkj10.0 W capacitive reactance?

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116#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the total impede s43 lrypjow)wyz.i-rk))p -)q( d*v1tdl bpance at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connecqb)r.(evp jo)3y --id w 4 )ptrpdzl1*sk)wlyted in series?

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117#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle at 1500 Hz if a 100-W resh f2t2kl vgzc yh8u)y*h8 zlh)0t5) xeistor, 20-mH coil, and 1.0-mF capacitor are connected in v 2lhut ct8kh lh2y))geh8z5 f0xzy)* series?

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118#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-m(fft9ij3hol 2p 0bey)H inductor, what is the impeb2()o hffl0jty9i e 3pdance at 1000 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-mH inductor, wzxx19/etc u-d hat is the phase e9 z/tux -xd1cangle at 1000 Hz?

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120#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in a series circuit with a 20-mH coil and 1.0- usqn-yhl2 ss(0 ;u hjb8na do,xam928mF capacitor for a total impedance dyml jsa oa b, h9uh0x2(s 8q-8un;s2nof 100 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is)whb abq* fjnjd2,j (/bw ;v+k needed in series with a 100-W resistor and 15-mH co*b/;+w2wb njk )dav( hqbfj,jil to get a total impedance of 110 W at 2000 Hz?

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122#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance must be put in series with a 450-mH indus,vmri).p2o:y 2 9* sj ss:e1 qrcdkolctor at 5000 Hz for a total impedanr o s isyrklp:v, sm122:9o.jc*d)seqce of 40000 W?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in series with a 1006kig .+urtwz65 cgky0-kW resistor at 1.0-MHz for a total impedance gu0 w k5gr. +ycz6ki6tof 150 kW?

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124#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected in series with a 20-m+*07wo mor dyrF capacitor. What is the impedarm d y*+0owor7nce at 1000 Hz?

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125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-mF capacitor at 1.0 kHz for a tpgzmsrc3ix24 oi*6p(bu 1k( zotal izrp(6 cb2 opmi*ukz(1s4ixg3 mpedance of 45 W?

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126#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-mF capacitor at 1f ocvb:qv6lst /t2a;7w3q au3 .0 kHz for a phase angaa3blvt q:otuw7f6 sqv2; c/3le of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is nr;qw 4j:vgyo mdbus*5k il5j 7lb*k23eeded in series with a 30-W resistor at 1.0 kHz for a total impedance 5j4*rg3bokblk jqi; 7l5 :y2 *swdvumof 45 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series witgyr:4 qzxv5 1ch a 100-mF capacitor at 120 Hz. What is the phase angyr41xqc 5: vzgle?

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129#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows at xw*itf+ /s y-s+rod f+5.0 V and 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor x+ sw+ dy*o/ tir+-ffsare connected in series?

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130#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit consists of a 100-W resistor, a 1o u)8fn v2uy-n0.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz pvo-8y)2nufn uower supply. What is the rms current in the circuit?

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131#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistance of 55 W, a capacitor of capacitive reactance 34f;(n f+wgsx z0 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz power so +n4x(zfws ;gfurce. What current flows in this circuit?

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132#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angb6.66 ea estrg:)vpvele for a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when cvge6p a:6et)ev6 s. rbonnected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W res8c.i6b o e d/1,yadcgvistor for a phase angle ofv1d/8ygi ed,.c bco6a $40^{\circ}$ at 10 kHz?

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134#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit has R = 20.0 W, L = 200-mH, C* i/;;b woym 6id-rdnr = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferred from the *di i6rw;nb/-; yr mdodriving source?

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135#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power output in an ac series circu9 mvju.+( ljgkit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V pok+lj.vg u(j9m wer supply?

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136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an i - iz;u:i4zoaswhceaos)s/ 0fe-1 q0 AC circuit is $63^{\circ}$. What is the power factor?

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137#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ac series circuit has an impedan7 lm50glx+ho/y0ch plk qv1 4kce of 60 W and a resistance of 30 W. What is the power5lk 70clhgv 10m+k/xqploy 4 h factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series RLC circuit containing a 50-W r77 r kyk +ucme.ti3sm(esistor, a 10-mF capacitor, and iuy7.7 tem (3 skrck+ma 0.45-H inductor, when connected to a 60-Hz power supply?

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139#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the resonant frequency of a 1.0-mF/cfsmiij-yd) 6d e) w( capacitor and a 15-mH coil in series?-d(wy6/jes)fiid mc )

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is needed in series with a 4.7-mF ca(o o+4..g szurfn8eb spacitor for a resonant frequency of 1rsfz.(b8o4.os u+ neg 0 kHz?

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141#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 3.7-mH inductor v zab+mh y.7 pn08voy(for a resonant frequency pna 07.yoy8zbh+(vv mof 1000 Hz?

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142#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor must be p- a68j* ou*nlfk)baqchcu) k4laced in series with a 30-W resistor and a 40-mH coil if the resonant frequencyflj cco6*4 hb)na-k)q u *8kau of the circuit is to be 1000 Hz?

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