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

 作者: physics   总分: 142分  得分: _____________

答题人: 游客未登录  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 are units vy;4 mid (t4as2e0krrdh cc02 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 ind4ec+(icgrsk + uction states 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 wire in a coil produces what kind of change on tt: p0;ap4vupjr hp)1l7 t6tmkhe inv4m6tj1l)p;pkt at 7u ph0:rpduced $emf$, 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 wir27-l8nnq diz ii5 jho5e produces what kin857 n5q-lin2 odihjzi d of change on the 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 prodk)byn ;v9,t byuces what kind of change on the inducn)9yybkv ;,tb ed $emf$, 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 from a magnetic field .yx80bm -phd3j k; juy1u +e;dckf(xu 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 direction of an induced current in a t pl8 vc)*gbl .m;m.dswal x(is+.j9j conductor will be that which tends;) (l+8 a.vjwjclg.p xtmb*.9m sdlsi to produce which of 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 table. A bar magn jt0t; zc-cv1p rx2w;jet is held above its center with its north pole pointing down. The stationary mag;2v-j1crxj w0 tct ;zpnet 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 onipj- (y(-cmrh* +9tuhjqs:bj a horizontal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magnet induces (wheny+*h :uts-j jic-mrh 9b qj((p 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 a9 hdbeqs4 c7 mpt17xe ci./7gt table top in a region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what 4pc77hxb1 eq e9 mg/tsi ctd.7is 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 a rg:(gx eu4b5nykk2 es2egion where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, wha2ks4yk5(u exgbe: n2 gt is the direction of the induced current in 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 ta y; xgf-)b(/ o*z-kkbtlv4 obyble top in a region where the magnetic field points straight down. The magnetiylvk b (bf b tg;x-kyo-o)*/z4c 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 wirenf :fe 6)zc6fpj, d,xk lies on a horizontal table and carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either side of the wire. When viewed from abov6 zfckep :6jf),dfn,x e, 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 north pol+o.xr i3bqm8v6u o1ls e entering first. As the north pole enters the wire, th8msv+.orlio3x qbu16 e induced current will be (as viewed from 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 s mu4t4 plly-e ;m kec)tn1ma16pj9 i0at 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 orientation of tc)mey1 pmtu1a6pi0jlkse m-tn4 4l 9;he 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 rotated at constant angular speed abl +wd j6xtpokp;(3w q,out an axis whose direction can be varied. In a region where a uniform magnetic field poin+q, jkpxt(w3 wldo;6pts straight down, what must be the orientation 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.jdx9 a-v8r7bjz )mx8j
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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 that :mo 6,xqivaw8an $emf$ 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;unt c*5m6zp.w 5jr dh magnetic 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 (ori1 .xbpngp; 9u .wjtwz:ented in the east-west direction) is moved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potentib;zg9:xt j .wp.p1wun al 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 veloh/9wa9s:d 6v // xf/knwshmeg city $\omega$ 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 transbvl/ sg 8,whr u,7k2zhvc/,ib forms

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24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator coil rotates through 60 revolutions each sorz x+9+by +a h.vw5ijecond. The frequency of tvai b h.5+wxyzjr+9o +he $emf$ 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 device used t3ytewh2 3gt**iw e,qeo

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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 thyf1 mcls 8 f6gp3/ir/mat

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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 seco:2jg lgmkr)z+ndary coil contains more loops than the primary coil then it is am r+g:k2 g)zlj

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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 pria 2xkhvq) , 6av0ayty(mary coil contains more loops than the secondary coil t avv ,x6tyaya (kqh)20hen it is a

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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 pow(;y (ot+v prqzk0 :jqb 6n;nxner 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 circ6s1f4;ck zzn uuit,

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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 ina /wnthb /g1t 6gqdhwyi14(2xductor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, theyw 2gg (bq itn//11x6w hdth4a 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 6)h3ubkpry b0to an ideal battery of constant terminal voltage. At the 6h )yrub0 pb3kmoment contact is made with the battery, 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 with inductance L and resistan pebec ix+(7, fq:a+cnavo,p 7ce 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 con -kyt7c 9/nk(ftkq4clnected 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 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 sdz vhi.owt/h7ak76 3 series to a battery. The time constant for the circuit represents the time required forohka d 7w7.vs6z/ it3h 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 to a battery. The battery4+ ,noo 8vauewi4, tei is suddenly removed from the circuit. The time constant for of the circuit represents the time required fwo+ ,o4iu8ait ven4,eor 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 g9u)*fy.b sthqs :p2zunits 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 supply. On this circuit, the vjd-0d q5,lg0efu 3zkcurrent

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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 ai8s:f: j0.tnipbk.zxmx z g35nn+7n power supply. In this circuit, the currenitn i:xzpbn7:k3n gsz8.jna .+0f m5x t

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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 cirmxu da 8(7yo86ckg7pdv:nf( hju 4k* hcuit changes by what factor when the frequenco(4udh( 8 v6:khkjc pyg7 *87aunmdxf y is tripled?

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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 doub1tw -vh8c kdchpk 7h()led, the inductive reh8k cvk)wh7-tdh cp1(actance of that 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 zero, the indu a(u;,gez8 ybjs6 q4eact g jaqez6 y,(4u8b;aesive reactance of that 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 thi-0n .fo l8iptds circuit, the current-0tpin f .o8ld

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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 azqz2 ;8d61cuslyu l-r n ac circuit changes by what factor when the frequency 8us6c1u lz-r q;2d yzlis tripled?

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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, thekve.1fa . zl-e capacezvk-fl. e1a.itive reactance of 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 betweq,zydh0+ot (xen the voltages of the inductor and capacitor in a RLC 0 dh(z,txq +yoseries circuit?

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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 RLC circuit is definedb b,,o ngvxi3; 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 z.) ,rjrvor5glr 4 pxyiq9y+ g+.4i fbof the circuit increases if R increases. When is jr. r yqf+x4r5rb,g)giz+.oyp9 vl 4ithis statement 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 impeou* 5ue. n,qqqdance of the circuit 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 circuit. The impedanyct )t 5/wz77a irxq,ece 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 the capacitance both double yk: tqd(lc4:u in an LRC series circuit, the resonant frequency of ld:(u 4 ktqcy: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 voltage. ibl l)9um+sx/5n b0siAt 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(tk::* 3b :iykn b:qlt0r5xu0 znzcgh RLC circuit occurs 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 field of 0.2c 2k:,z 8h , koa+3wmiqv bj;,l(qfmsw0 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic fimk m+wc3;fb hi,:q,v sw(,jklqaoz8 2 eld vector are parallel.

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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 mage-2dltrhxu-t- em+y, netic field of 0.20 T. F- yl-- ,ext2tmer h+duind 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 rotating in a uniform md;jic.tbq- ch se9 *w8agnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are at an angle of ih;wste8q.*j c d-9cb$30^{\circ}$.

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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 ekw,i21 u5pue 8i(d0:9a am uy.yl wxsreduced from $1.0 \; m^{2}$ 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 cha+zr.px i/ h30 ,0ad+ yehhhhownges from $4.0 \times 10^{-5} \; Wb$ 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 wv84tdx jy vb14ith sides 18 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 t48bjvd4 v1xy the 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 (6ha1 kard8ui 15 turns and an area 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 and aro p1)3u83y/gvar w :.jpct emrea $0.20 \; m^{2}$ 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 srtsnzi-+ 1tst ,-q 2mdpan of 60 m flies horizontally at a location where the dqnttmr ,-s2 1ds+ti z-ownward component of the Earth's magnetic 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 esir3c4 +*rblc3 vhpg -gs/. nrd:hh( that is 2.0 m long rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while in a constant magnetic field ofh*+np-r3/hb slh( rgcsd v:gr4e.3 ic $5.0 \times 10^{-5} \; T$. 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 and a cross-sectionalcl j fu0m8 dqy9vqi:t: k93q-y 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 consists of 100 turns owu6 k(;q5afwgw ou;-ef 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 rectangular loops on its armature. Each loop is 12 02ctdeny ll qk1+i)+qp6u, g ibo +.umcm 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 voltage of this uq6q+) g1dlitkni++2e,m. yop0u lbcgenerator?

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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-acmt5h+vuamyf5 3. n 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 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 simple AC generatorz; 2ce.1ah(i/. - ufhtfoxvim with an output of 12 V ma.f1(ivthm2x fuai zoe /c-;.hximum when rotated at 60 Hz. 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 wcc2s7d:nhwk2/ 1 8wfen*g y bfith a maximum $emf$ 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 motor operaty*iv) ,cn7t+ ,z-c9 6irvmri 5atf dd4wi,htt es 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 ha;crlu b8 p2ned (h7xme5 *-kt)yg.yoa ve a resistance of 6.00 W. The motor operates on 120 V AC, and .le7 5nc)h r-g;82 eo*aypytm(uxdk bwhen running at full speed it generates a 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 24-Vf+npi,l *t ts9 power supply. The operating current is 1.0 A. What is the start-up curp 9 ,*ltstifn+rent?

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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 n 3reo:wkzlzgj) ke 45 0kl;p6g 3:kacis connected to a 24-V power supply. The oper6:z k3rz5 40a3:nwgklkelkp;jo)ecgating current is 1.0 A 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 connected to a x* lft.d9s;nx24-V power supply. The operating current is ; x9tdsfl *.xn1.0 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 neede vao85k0+qrwp d to reduce a primary voltage 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 to flow i e)2sqbdqk fa5)ci qf/0;ly 9fn the secondary. f9; 5sflbqcfq/ k 0yq id))ea2 How many 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 manyw) 4/h2u1zbu0brz: sc7reh pj turns are necessary in a 110-V primary if the 24-V second 4ber7c :2zz/)1hsp0ujbhur w ary has 100 turns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consist lky7wep0b4l4 pxu.5xs of a 500-turn primary coil and a 2000-turn secondary coil. If the cu50 ppbw4 7lxleuy.kx4rrent in the secondary is 3.0 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% ef) br v3xy-ry* a+on ap/(ih*huficiency, how many amps at 2** +aby rnuh i -)xhra(y3pv/o4 V can flow in 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 sbdccn ;/91sz sign transformer provides 7500 V at 10.0 mA. The pzsc bd9; c1/snrimary coil operates on 120 V. What does 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 60j ubj/-v,d i3yk)(gvw turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary,j-bw,()j/vv id gky u3 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 6 1kcboxhp+y6 5k8m)r r0 turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what c1cm +o6y85kh )krrpb xurrent 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 secondary h fn44o-*ub) oyyecv.pas 200 turns. If the input current at the primary is 100 A, we can expectp ovoye4cu*)f.4byn - 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 turns and its seconda mca0:xen jk02ry has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltage of the secondary to be2kemcxa n:00j

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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 5 dd,m v tfte(k/p 3wfmmgl92, g-9qlshas 200 turns. If the power input to the primary is 100 W, we can expect the power output of the secondary fll-mf pv3(59mm ktd /9sqgt2,edgw,to be (neglecting 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 currex 4jlo5y(c7ubruib40 nt at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitteroy4 b(c 7ujxil5u0b 4d 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 vran5/ cg(qsi(oltage is usually stepped up to 4500 V bysqc/a5 g(r( in a transformer and transmitted through a power line of total 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 az(wvtm2 0gv-pl.-hvbi03 gd vt 120 V. The voltage is usually stepped up to 4500 V bvvvl t0 g. bpd32- (wvm0giz-hy a transformer and transmitted through a power line of total resistance 1.0 W. Find the 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(d)qp,kury b+ has 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 +p ()qyukbd,r lost if the 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. A gene2ipm rz +sos2je825 zurator produces 100 V at 70 A. In 2zemjzo p52 r si+u2s8order 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 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 poweit562wcmbs( jomca . .3ccr9ar would be lost if the power were transmitted at 30i 9(accrm5 3c. jo6wtscm. b2a00 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 4 fv.lr)aow+rgd9e4n h n4d;g(40 V at 20 A. It is to be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a transforlgda +)wv.n4drf h4(e ;rn go9mer 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 currenqz.j nhwjdcf3llcp/vu/.ds .; ; e-3 at of 5.0 A. How much energy is stored in the coil's /a fd.3. pljsqnv;jd- u3w;eh .z lc/cmagnetic 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 gcp shu;1yihpb,t0 -*g--ko h 3zzf-cinductor. What is this circu3 gc- pb-osz-*h ctupi ; fy-1,z0hhkgit's 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 wherep djq /3+fzwuc/t/ ct* the 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 the peak cur9;qapiq1 i2 uqrent?

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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)axz hxseh00 j;l84s t outlet. What is the resistance of the la) sashz4exlxjt;h0 80 mp?

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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 a 120-Vjkqcz 3,;z8c 5odc,:es ecso ky7p68 q ac power supply. What is the peak current through the resistorkcq8osjz;65ks epo: 3c7 z,qdce8,cy ?

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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 cofhpqc k5w:/4 :4rostib6+v l c. utm6nnnected to a 120-V ac power supply. What is the power dissipated 6hrv./bw: :tm 5tcfnqs4l+6kc 4 poiuin 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 505 k n)mkm du)v)e0p/tz-W resistor 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 a 50-W resqe/ vt, wgiok5 (;jw5histor 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 resisto)jhhmco e 1o:aiu4r,jtbss f3d ; y69 c64+dpur is $I = 0.80 \sin (240 t)$. 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-mH i(0kwnaooqv5qpr 4 6swoo z5iw q 49+;pnductor 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 2.50-gbr6 ,a, 9gy7.t r5p2fvaet pdmH 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 havobu jx8n4bn+ht4 .jf(e 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 1xy+0v y3pm;,n;y :ygmkjk t ( tzf-xy)a4 o.vw57 W of 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 whb1cdy5 ; zm(xgen 120 V AC at a frequency of 20 kHz is applied to it(5gbczx1m ; dy?

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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.fdaxfu 2opn/4(*(9/ u ea+fkmmr hx r)f y,id250-mH coil 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 reactance of a 4.7-mF cfcmcb50z6mkt*j 8h llfhem bkj (k*wb 59s .3-apacitor 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 50c rmzz0+ekbsb:x3:j 0 W of capacitive reactance 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 capacitor have a rea l6pzr:-yg wm2.9ds j iqi*:tx6mzbm*ctance 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 a 0.010-mnd 1.j djida6)F capacitor be 100 Wjdn)d16aj di.?

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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 through a 0.0010-mF capacim:) rhe,fn cob/b9 /kjtor 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 series cir,e 9v/hc,tghscuit with 12.0 W resistance, 15.0 W indu,she 9tc h,vg/ctive reactance, and 10.0 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 impedanchn.vz )z5 pc8u5r 9izse at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected inzcz.hz5 5psiu9vr)8n 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 resistor, 20-mH coil, and 1.0w wgr 6(xbmc3rsr7r /(-mF car36rwc rbm(/s xwg(r7pacitor are connected in 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 ly(3e xklnz75q(q:q.w7 rp vf connected in series with a 20-mH inductor, what is the impedar fn3e5q 7p.llkq (x:( zw7yqvnce 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 c eas1z1r. 9tu py;*etwith a 20-mH inductor, what is the phase angle a.y9tzr* sa et ;u1pc1et 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 circuif6ck)jxcm ,4*ppucv. bs .t o.t with a 20-mH coil and 1.0-mF capacitor for a t*umtjp k,obpfc4 c . xv.)s6c.otal impedance of 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 needed in series with a 10(kul 9s.zj g7smn xc) ) 1t-feoi85vhs0-W resistor and 15-mH coil to get a total impedancj s v n-9sul5)o7izhg ckm )t8.es1x(fe 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-m)ry mpiu9(b )lsvs/ dnvn164d r8vkh5 H inductor at 5000 Hz for a total impedancer8u r)/mn1s9d 4 dyv b6)s 5plkhvivn( 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 is me5*bem(;,qzz lu0vn series with a 100-kW resistor at 1.0-MHz for a total impedance of 150 , m*b(ez 05usqvz m;elkW?

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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-mF capacitor. What is t0*4o5)rj ;hkphm0 u1vslc frvu(j *su he impedance at0 rh um l*)04;* ckjs juhfu5p(vosvr1 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 wit15c s1ytsxl995 nkvh)qv2j+ w (meoae h a 10-mF capacitor at 1.0 kHz for a total impedance of 45 2h vsxm q jo) wke1(19aecsnt9y v5l5+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 1.0 kHze cqk*ol:)h 0gh1gj-4 mi.tzx for a phase angle cz 4qkho:h)x. jt 0l- *1gmiegof $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1.0 kHz for a xovq1-f8 ehvqfnf48 /total iq-fo8v/qefnx4fh1 8 v mpedance of 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 with a 100-mF capacitor at 120 Hz. What is the pj *8krcun2 lt: c;qj8phacnk8jlj2qu*cp8 ;:r t se angle?

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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 5.0 V and 1500 Hz if a 1ih(;2pd/ xm gz- /o,lxh p/cby00-W resistor, 20-mH coil, and 1.0-mF capacitor ar/2 l,-; og/h/yb p (xmipdcxhze 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 10.0-mFvnw(:dnr y, 0 wan9w3e capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power supply. What is the rms( , nnv9n3yw0dw:aer w 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 i2np .,chyn7f, a capacitor of capacitive reactance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz power source. Whatph .ynci ,7fn2 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 angle for a series RLC circuit containi1f5zmz hcs5k3 ;q s7oyng a 50-W resistor, a 10-mF capacitor, and3;qshf zzkc 51ms 75oy a 0.45-H inductor, when connected 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 w(,ci,oky.q jzith a 500-W resistor for a phase angle ofok q.,,iyjc (z $40^{\circ}$ 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 = 10.0 mF. At wokn *s+ :56,yh)tit 8ojoxjmdhat frequency should the circuit be driven in order to have maximum power tno*) y +ht6k8 xjdo ,:tsom5jiransferred from the driving 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 serd )6ue y47e5xbyfkh4mies circuit with 12.0 W resistance, 15.0 W inductive reauhm4 b65fex ey)y7k d4ctance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power 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 AC circuiajcn+ ag6*+glt 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 impedance of 60 n. o)j8ufg7xb W and a resistance of 30 W. What is the power fac7jgb)8x ufo.n tor?

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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 resistosh skwza(2 .n a27ejw*r, a 10-mF capacitor, and a 0.45-H inductor, when consh n2. w7sk(* jewza2anected 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-wz 2j( f;m7etvhvo9s of a 1.0-mF capacitor and a 15-mH coil in series?e 9whjvovzs f (;mt27-

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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 capacitor fm6der)lq o) s*or a resonant frequency of 6*rd emqo))ls10 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-mqz4sho 8p sgm300wrw;H inductor for a resonant frequency of 1000 Hqwpo3 z48s;s0rwgm 0 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 placed in series with a 30-W resistor and a 40-m jw i8xj9hubz+2;/w tkH coil if the resonant frez/j8 +j9 ;2ut wkbhxwiquency of the circuit is to be 1000 Hz?

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总分:142分 及格:85.2分 时间:不限时
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当前第 题,此次习题练习共有 142 道题

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