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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 are units oqfzt( /:s,eh b +e9(krzy1r/. f qcujef 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 states thvyy y;b(w8aa p87 +* bxa8spvyy;5e zhat 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 pu6alm 20 ako3kind of change on the induce 0palau3o26k md $emf$, 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 prody4j x,l, fmd;euces what kind of change on ,x;lf,4deyjm 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 produces what kind ozgl -,vnr5)x zi*-pky0k ,y tdf change on the inducrdx )iy,gy nzkv * z0lk--5tp,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 anp9ncb:s plavuyr g,- :k:;p4u $emf$ 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, 1(35 ag l5l t y1efyelo6ze2ylthe direction of an induced current in a conductor will be that which tends to peyae5gy1yf t(5l z6lo2 1el3lroduce 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 magnfl;;-yz xj:g sqo k.75s)dhypet is held above its center with its north pole 5y p;7yfklqh s:).xs;dgj z-opointing down. The stationary magnet 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 f90 :;rner/pynn6-d od f5dwnhlat on a horizontal table. A bar magnet is held above its center with its north pole -p dr5o 9/6wynnf:hn0drd ; enpointing down, and released. As it approaches 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 t*n;hi yckcj k7 t6h+0ug0zpq9able top in a region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, w n6iky+c9tz0h07* p ugh;qjckhat 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 icn) n:.ldu: )* lk sch;z5jpaa region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. Whe 5:iuzhsp:) .j lnk *)ncdcal;n viewed from above, what 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 tablrzr/q-cgi:)cw cjk- g/i+2f z /vlw r8e top in a region where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, what is the direction of the induced current in this coil as the field disap+kwl2 g/if/r-zjrc 8qcr c: i-)g vwz/pears?

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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 ever-increasincse z;tv e07)k:(qbzqg current northward. Two coils of wire lie flat on the table, one on either sievc (0:;k eb sz7zqtq)de 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 f v 2br8em,ob j6rv3y+with the north pole entering first. As the north pole enters the wir2m+rjy ,bfv8 erv3b6oe, the 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 at constant angular speed about an axis wkku3f -(j1daohose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's ax1-u3adfoj k(k is 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 2 jtd:k77dp3qo)yxm langular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight downmo3:)t 7yl2xp qjdk7d , 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. vhy8 /-6sr(pgd1)mw6ertb b l
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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 thatffl +*q,g jtbfb2pkqjm2 .c7 , 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 magnetixbmt-2x(1g0w ja3v wp c 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) cya ;x;ixz6 m/4uf7tnis moved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the6t; c/af 74u;nixzy xm 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,vt ;*suoa.yi+6,lnka) cxoj angular velocity $\omega$ 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 tr mn;jlrk* m5,sansforms

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24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator coil rotatesq:xj 2cn.ai .vl0ji)p,r-sgi u7z f7d through 60 revolutions each second. The frequency of the j jv77 si.l).p,:i0gf ci 2zdrq-ua nx$emf$ 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 ibg()1e zt f c)9-n,.yivbk leused 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 dw156 iv.ta3lyc2tvxb2cyj6aevice that

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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 sl/ 9dxa6, thmtecondary coil contains more loops than the primary coil then it is ad,tt/lahx m 96

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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 prima)9/yy6ui 0 bchlw hva;ry coil contains more loops than the secondary coil y0wyc vu;ha)bl96/ ihthen 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 power /bf z601suzj6lg nts: 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 cd6m;dbmg v4 v7ircuit,

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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 itr3kgb0yv8 ,fg7k g0e deal battery of constant terminal voltage. At therbkte0ygg 3,g87 vk 0f 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 battery offghiqh c*5 x9- l6m+kg constant terminal voltage. At the moment contact is made with t5 +mk9-ifc* h qlgh6gxhe 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 akq 5 o1xrypjbiba57/ )q md+g:nd 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 indupt le(3c9n-coctance 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 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 ind8(6wkr/lxjlxz qyr6 c.ro 5u;uctor are connected in series to a battery. The time constant for th8 wlu.yxqzrxlrk 5/6;j(6orc e circuit 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 to a battery. The battery(y z )wrjzx8g1,zih7d is suddenly removed from the circuit. The time constant for of the circuit represegrz)1 y8whzid,7( zxjnts 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 havq nhg5j4w ;f(qe the same units 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 c+ ed i3)n8e oe3qp);9pcb4pra hgxju/ircuit, 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 supply. In this circuit, 4b3ps:qlbn) i the currentp4n:b ) lsbqi3

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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 8b0jxnc, : biqt4,cmt by what factor when the frequen,c0ib 4x mt: btnqj,c8cy 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 doub j(gmtg.*e o)cov :bq/led, the inductive react)/g(oqogc .:*vtejmbance 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 voltagw(2nq ; x sflfrnlj6me2to:ig4r(- +ze across an inductor approaches zero, the inductive reactance :zq;2oisnmw g2ltj le-r n6 f4(xf+r(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 connect-)yhw hah.syzb,a 6n; ed to an AC power supply. In this circuit, the curren6 ;s yhz,.-hba)h naywt

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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 change0ni 7b +vly9-zp)fy3nvm/ zr ks by what factor when the frequency is tripled 3pmr-zz)vyl ik/n0v9b7+ynf?

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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 v9 ogfhn( 8y+749dwrrpha/h i across a capacitor approaches zero, the capacitir 9n8hg9i a/yd+4hoh(v wr7pfve 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 between the voltages of the inductoacj0tv(h;i, l r and capacitor in a RLC se l t,j;ch(0iavries 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 circui42rts ol1xra 8t 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 circui+s;ht u o6rhauv4u q1 x1u+7ppt. The impedance of the circuit increases if R increases. When is this statement ;u7 ruho6vpu4h+ua1ps + qt1xtrue?

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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 impedoryb p6f2-w,l 5tm z,sance 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 impedance ofvh.:: t.yjxzvu sh f de;8d/c8 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 in an LRC series circuit, th.5+a) aq 4u*zigqxlyr e resonant frequency of tha. ayu q+5)gqzra4*ilxt 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 driviy2+ u+ndsf l/xg:e* sen by an AC applied voltage. 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 a di)fgm*1nr9+(dbjn 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 rotatitx a5wj+i1e2mng in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when t15+ imaw j2xethe plane of the loop and the magnetic field 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 ro(xie4f m i7annpg 6e,g vj512vtating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane oifin ,7 42xjg5v (vp1emng ae6f 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 magnetic fielo*pe7c2w ouw z9j4 qun))4aza d of 0.20 T. Find the magnetic flux through the loop when the plane of t puz4wuz7wqco 2on*9jae)a4)he loop and the magnetic field vector 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 fro-mp0 ch.eoz.pf g pqu. qc5d;.m $1.0 \; m^{2}$ 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 changesbr ok2bns 8odp7, j4-97jjj6 hq *hl7b3ga bva 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 fra q0/m2v(yt issme with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field chaqv tssy/0 (2imnges uniformly from 0.50 T to 0 in 8.0 s, find 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 15 turns7 7v.r4p kf+kdf:wlxk 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 nd yw*to12;:zas.bbnr; h1gbarea $0.20 \; m^{2}$ 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 horizontally at a location where the) .lchd6 zb;w/aadggl8/aix 8 downward componeaxa6)iga 8h.bldd ; g8lzw/ c/nt 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 that is 2.0 m long rotates ath)zgm1aa 0fg j.aj7x 4m4pmahw1 j. :x a constant angular velocity of 2.0 rad/s about a vertical axis through onz)m jw4a1:majjx hpm.ax 1 fgh0a7g4.e 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 and a crosn+ xhr7 ra--bhlru2h4q(dzm6s-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 consists of 1v p tg g2e.d(czeah0n:m 8uyva*+3c0y00 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 rectangular loops on its armature. Each loop is 12 kca/ (; nkxvw4k7 9uuxcm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rkx k n7/x;u4kvac9w( uotates 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 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 consisgsw+rn1 /-yrccp tm i.;oumk0m2w,- lts 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 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 wisqa-j3.)e x*n0s dqhnth to construct a simple AC generator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If tn h0ade*3)-x . nqjqtshe 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 map/szv ;)1fpp0c6yibb ximum $emf$ 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- 8x8mc d(od(aeyvvg5 have a resistance of 6.00 W. The motor 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 have a repu5 mj ,kcrgfza9y8p ;1r9db-z fy )l2sistance of 6.00 W. The motor operates on 120 zp - 91zy,2)rgd ;fb9c5jr8m u pfayklV AC, and when 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-V power supply. Th7f w*1o5pwo-* x+5epdufrjn 9 slds)we operating curr s)xe9 *fwjn w7+ wspdur-lo*df51o5p ent is 1.0 A. What is the 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 6.0uju8.gg) 0dcz W is connected to a 24-V power supply. The operating current is 1.0 A at full speed. What is the back u)gudjgz0c 8. $emf$ 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 24-V pow4wxs-ooe,+3or6 s myj er supply. The operating current is 1.0 A at full speed. Wh6r ,yo osm43soj xew-+at 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 iscw,w:(y2h i wkx w1d7g needed 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 iyug.k.d(yg v0 n the secondary. How many turns are inv.( dk. uyygg0 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-V primarybe3ksh k-ng2 . if the 24-V secondaryb 3gn-hek2sk . 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 consists of a 500-turn prim49xq 2do 9gf4uyvn.rbary coil and a 2000-turn secondary coil. If tdnyovx2 r9.4ub9 qg f4he current 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 ofdc nqjqg5z41e0bx0- v a transformer. Assuming 100% efficiency, how many amps at 24 V can flow in the secoq be400 n1cj-dxg5 qvzndary?

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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 at 10.0 mA.6ps8qbt d6-cl The primary coil operates on 120 V. What does the pbqstd686- lc 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 primary coil and 300 turns on ifhkjnu.1tf i9/k;v3yu9 ) aggts secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is present in the secondkiua j9 gffgtv9k1 )3hy/.un;ary?

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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 ts e*g5f6o r/;0mpx igcfu23 azurns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the seconugf ioga 3x/z2*fme; s65prc 0dary?

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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 transrq5xfg4 5egi miz834uformer has 100 turns and its secondary has 200 turns. If u4xrgz35ef54mi giq8the input current at the primary is 100 A, 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 turns and its secondary has 200.gr7se/jgoj- turns. If the input voltage to thog ejsg/. j7r-e primary is 100 V, we can 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 tu ;hull0q4/j 0 gqp/npzrns and its secondary has 200 turns. If the power input to the primary is 100 W, we can ex4jpl glz/q h0uq/0 p;npect the power output of the secondary 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 current at 120 V. The iawb-prkf t2ac -bqq*q*o1lz88 (-dvj a ov+ 4voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resiqq*kz+cq abdip 1o8b o -tv(rlw84fa2v-j*-a stance 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- ujmcixyeh6o4 s5/d 3 A of current at 120 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 pe35hjucydo46xis-/ mercentage 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 120 V. The voltage is usually steg *ebx4) 8x9xatfic4 wpped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lost in the transmissiot bxcia)w9* 4gf 4e8xxn 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 ha0apsjzz6;sqyks m z m0+//.xjs 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 tmj .zk sxspas;zj/+0zyq m/60he original energy would be 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 0t3kbw9 dzwqh ehq .5/7.60 W. A generator produces 100 V at 70 A. In od kbh93 w/qhw.q5et7zrder 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 transmittecmqzwe,te k-d,9 6xh3d down a 6-W line at 1000 V. How much less power would be lost if the pow 6d9 hz,xq mete,3w-cker were transmitted 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 2l,bt0 8tae g.j6y4mkk0 A. It is to be transmitted on a line with resistance of t4t8. ,bgem6 y0kljak0.60 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 the af rh8yb*-qt; coil's magnetic fie*h;b r-fa yt8qld?

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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 resisxa/q sklrdcj a(.n1oxkc f40.l( d7wmd 8o2l:tor and an 18-H inductor. What is this circuit's t x cad0aq(d.lokm8 :/4 sldcx.nf(ol2 wr17kjime 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 the rms voltage isb c p(g18xzqc7nk5;ht 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 peszk/: ew0 s+. ncvuth*ak 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 outlet. What is the resistance onaf-rdc-; 2 rtf the lam c td-r-;ra2nfp?

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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 wri1n4q lja1c(di 9)y to a 120-V ac power supply. What is the peak current through the resi9 d wicrnjaiy1)1q(4 lstor?

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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 supplgnrowuvj))alh r2 s;5x e30n3y. What is the power dissipat je5on3r)v 0s 3hw;n)ragxlu2ed 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 4ocij6t(fw dp3tdk3 )50-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 resicf sdl /wm7: a(d20dvmstor 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 isps 9 gs1g,9rhe/as4ds $I = 0.80 \sin (240 t)$. 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 el wi 52epj3e4 q:f u3l-qmcb.of a 1.0-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 2.50-mH coil at 70(r/a u gwbhn vfb*+h1000 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 co)jq y,hg4usqltyf4kh 73 1*hlil have 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 foru3q19xloa 2 l-3frur /f*eglk7l0ryn 157 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 gv.six c4 jq1(qc +7co*sdft 3a 60-mH inductor when 120 V AC at a frequency of 20 kHz is vc gq.ds(3cs+q4 ijftxco1*7 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 coil due to 5v afj3 bfojqhn57;p-ego -f7a 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-vsa5i.uqe/)zfs( ,8m anzmt9 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 cas pjzf f;ry3):pacitive 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 d/ ct (30 hh 6k/wzaigqug1;hxa 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 th4. egt+m.lsgc jj(krr/ q0 ra2q:6khze capacitive reactance of a 0.010-mF capacitor be 100 Wm:zg/h6 asrrgq 2tj4( l+kck q0r.ej. ?

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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 capacitor at yx+2v72g y) adqwbp1zi8osow9/ u1 wx1000 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 circuitwx-fa, )x)b is with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive , x)swb)fixa- 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 impedance at 1500 Hz if a 100-W resistor, 20-mHwbplce k ,- :-rvx:rg3 coil, and 1.0-mF capacitor ar: -:pw rl vgckr3-,bexe connected 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 resistor, 20-mH coil, and 1.07oh 0l9 q//y.jpmy yze-mF capacitor are conneo /jl z7y 0pyy/.9mqehcted 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 connel6fdlf(6, lq dcted in series with a 20-mH inductor, what is the impedance aflf6 dl(l q,6dt 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 conapqhf*ui/o0wr 9* h31 pbsn:xug73z e nected in series with a 20-mH inductor, what is the phase angle at 1000 ap:uu3q ow*3f*h erg9n71z/hp bsi0x 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 ir6z p5q4rtx6xy(ik8 zn a series circuit with a 20-mH coil and 1.0-mF capacitor for a total impedance of 10pkxt5 (r8 4q6i zx6rzy0 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 100-W resiso(e rkas*g;i 8tor and 15-mH coil to *k ;sgeo(ia8r 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 serp1g:rtyvey cl4 f9 p)*ies with a 450-mH inductor at 5000 Hz for a total impedance of 4000 y) *ryv 94gt1celfp:p0 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 100-kW resistor at 1.0-MHz for a9s4vv(nn4b.: wpr jre)vwo :q total impedance o pvnr)o4qbw:e rnj (v9.s4vw:f 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-mF capacitor.uk ,zfft8 lawyk6 +m)) What is the impedance at 1000 lwa ,k+)6zmfkft8)yuHz?

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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 serie1tj)eg: m i 4 n+7plzcg.rys:cs with a 10-mF capacitor at 1.0 kHz for a total i1: e4:j z)iy .g7+rctgnpclsmmpedance 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 1 o:wd66gh:,e21t d5 cd nrtwg+ztzf1u0-mF capacitor at 1.0 kHz for a phase angle ofdz c6 w+6:o,hr1e:gdgufw 51tttd2zn $40^{\circ}$?

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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 1.0yw lic036:aswry eh2-l a, mrq j38ti, kHz for a total impedal26, mycwa-is,3:eh w0q8jr 3iyrtlance 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 capacism2zk4 3g3q cstor at 120 Hz. What is the phase angle?smk3qz gs4c 23

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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 100-W resistor, 20-mH cl13yji)9fxugvxa,6 f oil, and 1.0-mF capacitor are connected in series1lx j )iuv,93xa6gy ff?

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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-mcxj cmg4 kz3a)c0n8/yF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power supply. What is the rms curx8cc0)/j4nm y k3z cgarent 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 reactancehx o.1,anx bmmrc36-(osp-rw 30 W, and an inductor of inductims ,rm-1c(xbx.or-p ah6o3wnve reactance 30 W are connected in series to a 110-V, 60-Hz power source. 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 angle for a series RLC cnr wg;7fgq9) s ,2fzvvircuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connecte2;7s, vgzwf) fvrqn9 gd 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 d.qa)d4pasjj qu,,hvgt+e v z0crr3 (, n(sx:in series with a 500-W resistor for a phase angle of rcd(j3,0 tq,x4vz(+aneagp )dhsq. uv:, js r $40^{\circ}$ 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 = gp 0ku0 iy0lvwnu0akep;at 8p 4l7 ;j5200-mH, C = 10.0 mF. At what frequency should the circuit be drivek; v8l7yp0 0a4n5 e0jtua gk uplpwi0;n in order to have maximum power transferred 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 series circuit with 12.0 W resistance, 15.0 W brqm.jg/9uhl p-ces *;elc 0k6s9j m( inductive reactance, and 10.0 W h/mc 6pu9rsb (l9gjls0-cq*e j .k;em 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 kl3sw-ig 4m(9 lxgz,n 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 impedance of 60 W and a ry7vrrx28tbux7 t 9g 0resistance of 30 W. What is bt7 ygx2v 0rxr8t7u9 rthe power 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 dp+vjnnk)je * f,01 uhseries RLC circuit containing a 50-W resistor, a 10-mF capacit1jep,dnhf0 v)kj u+* nor, and a 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 capacitor anyuu72u/7y 60pl dojhek4csz8 d a 15-mH coil in series?u7l2 zeu o6py7uyh 4cd0/k 8js

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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 capacit ix+i a,h.en ng.c-ov7or for a resonant frequen -.n+g7i .oanc xie,vhcy of 10 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 inde/p66r ,m;frde y qqwb2j;1hnuctor for a resonant frequency of 1000 Hz? jr,q1;d;2ner w/y6qmpe 6bhf

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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 ;9 cnw*79nze+xobxj g be placed in series with a 30-W resistor and a 40-mH coil if the resonantz7;wxe9o g 9cbj+xnn* frequency of the circuit is to be 1000 Hz?

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