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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 agfobq. qae8rjb 2-6o -re 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 inductionrvaospnr :x 0c4 0b93b 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 prod(ebnc8p(i s-c tk/y v(uces what kind of change on thekc ybn i s-/(8p(tve(c 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 d +esarjgu4q k-k ;dnff, m. 6nd12w8xthrough a loop of wire produces what kind of chang1dfxf.d,k 8n ur da +j qnegkm42;s-6we 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.-28ak sk pyre)wytsb*eoc2 6 a loop of wire produces what kind of change on the induced bp8 e*woy k s 2-2tcyre.)k6as$emf$, 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 mavyt tms;rr(kx;.3d* o ial)ry : j2iq5gnetic 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 direction of an i6y0lxv7yq oiuy 4 ,3qqnduced current in a conductor will be that which tends to produce which of the following e,x0yq i7 v3 y4qolyq6uffects?

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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 magnet is held abov yt:rj1ihvqf4 /qzaodgkk ws69 0 74+ge its c 4jqki: sfha/yz9gd4w1t0 qkv 6r+og7enter with its north pole pointing 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 flat on a horizontal table. A bar magnet is helbo,w :z+ic k8kf)uh60: rv15bgslw w7d vp /icd above its 5:cw v)b1dokuwzf0,b ci+/ i8k 7ghwl6sp:v r center with its north pole pointing 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 table top w vj44/ dy/*zwznd6( 6f2patc u fyv;zin a region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced cuvdp2a;4 *y yw/n 6 /ju4twfcvzzf(zd6rrent 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 region where +yfue.ot u*)t10 yyl9 eg9ild the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of t+09tu1ldgfe9ty y e liy*)o.uhe 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 + n kn6h8l:uql t7hnm4table 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 induc:t64l n7umnlh+h kqn8 ed 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 ever-increasing c3q )r lpg-jsn)urrent northward. Two coils of wire lie flat on the table, one on either spj nrg-qs)3)l ide 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 north pole entering p/k0fljb3( maru4q 5dp hmuy-yk5 v 4(first. As the no0qubjd afmrl3 -4(m(pyvp 4 5kh5yku /rth pole enters the wire, 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 wir( aj+lqps *l53;x vrcle is rotated at constant angular speed about an axis whose direction can be varr53(xpj*qsl ac+ll;v ied. 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 syte:nm 5vik2/o*mqr:5p u* orotated 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 orientation of the loop's axis of rotatio2v*k/y*o5 q irutp5:emm nos:n 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.klss u+roz ldi(47nzrl80q6sh r,dmixv:) 52
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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 thatt cs,6 b cvq*t4rx1)gh 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 magnetic field.o,;eks+ wel3 o 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-wec;g a6 bvlgz0.eq8l /jst direction) is moved northward at constant velocity through a magnetic field that points straight down. Make a statement concer08g;gj.v aceq /bzl6lning 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 constg:xodh 0b wr48ant 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 generator5wn92 dyakc 4eukbxd.-fr83y transforms

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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 second. The freqz(ecf g/7mbtt4-n;idb z*h6 iuency of t; fbtdzzig *m -n76bi( ch4/ethe $emf$ 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 urp42ak:p v7 mcsed 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 t bh+cbi7axeas*19 .bohat

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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 secondary coil contains more loops than the prx*am47 3ufjbn63wldrimary coil then46uba7 mjndf*rl3 wx 3 it is 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 contains more;n w+j0(0doietwq9ni f/:wr z loops than the secondary coil then ii q t(0o;njwndr:e0/ 9 iww+zft 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 inpub,h,3 :yc wg3qqb5pyr88pbui t

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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 cir8 qb::.suv ea hr6o eioqr j-suyo::94) vgg;acuit,

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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 battery of i 8.u-g9 k5 eg1uzxjspconstant terminal voltage. At the moment contact is made -ip1k.g gx5s ezuj98u 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: n38 uo3n8dra 1crfsd;qhkunl;/s0v an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltag3s anlr;uq81ur 3vkdc:nd 8/0onhsf ; e 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 resistance R is connected to an -:sgb (g*mhld $emf$. 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 connec sbul*ni3 )h0oted 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 series to a battery. The time con6vhsgpdac; vo k ,.n*hek2y,/ stant for the circuit represents the time required for the cu,hsk hvg/cn,6 ak.;yo2vp *edrrent 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 ./ 0mj/ vxuf7cjpt xo7battery is suddenly removed frov 7tf cm0.j /u/7xpoxjm the circuit. The time constant for of the circuit represents 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 hjsl+ -qvfx73)+;w f2tdbb ap lave 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 thagr a5u+3bw;t2* qwb2jwv/te is 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 conn+e8q 0 b3 usgfqk5rv*uected to an AC power supply. In this circuit, the currentr b0uq3eug*q f 8v5k+s

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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 factor when th mb-e6gxr/0 jce frequency is6ecbj/-m0grx 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 doubled, the ifhdkj5 t9 zng:ph+b ,vz/f0t.nductive reactance of that i:v hfk hz9njg .d/tzb tf5p+,0nductor

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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 iq*3tms 3mqikh 9,o) 0ksc6+yu akrmr7nductive reactance ofhsk3 omm*rm9+k60 c,7u)t3qsir yakq 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 pom6n pbj3d)h gw4pt7q2 wer supply. In this circuit, the currenmd7)h pg4t6pqjb wn 23t

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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 ch 3lsh+8ww k;hyanges by what factor when the frequency is t3kh ;+syhlww 8ripled?

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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 capac2ueux9k;17bbgwac lr (i9+ltitor approaches zero, the capacitive rcbg l;u (+l7a9b9w2etxrki1u eactance 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 induc.g*ndae1 .dr3md/vge tor and capacitor in a RLCa. 1d/ggd.*e3em n dvr series 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 cir//nqo; tujun: f1fqm1cuit 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 incr q 8h- ),cxof5q7buma c15 ga-bepfsp*eases if R increases. When is this sta,8mqqp-b )he1fbux5-gs57pc f* oa actement 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 impedanhj : 4jus7/:/jvc-d4zo+bwy3 + l wbvkvruc2lce 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 c.l5 cb3x j0ga79lftdy ircuit. 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 the capacitance rum j gpje( bz/2*v2b9both double in an LRC series circuit, the resrzg *9vbj2uem b2(j/ponant 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 0 o msw6n94h);uerxd 7f;y8/nd,kchang fzw-that is driven 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 RL c2)i 0oyby4zjC 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 ofk(f lz* *q 6;35yvb0vn l haz41hycngw 0.20 T. Find the magnetic flux through the loop when the plane of 0 *l 5 ;avnbqy(ghkz14 nh 6lyf3zcw*vthe 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 rotating in a uniform magnetic fih4sc .9)aisxa eld of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are perpendicul .iss)4a xc9ahar.

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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 a5r ) eu03quqi*nnj .jrwnt;) a5jpb8ss/: jc field of 0.20 T. Find the magnetic e 5brn)r35 .jq*/jjinc uqu;jst):nwa ap s80flux through the loop when the plane of the 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 loopmnla,* 7ptzpch m;05z is reduced 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 coib2y hbj2k( 9;rnxv *ii-8by xdl changes 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 tuoygio 1; h6g2drns of wire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field c ogy62o1di;g hhanges 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 turns and an area of 3sp* qq,+8iayfd o/xs$0.40 \; m^{2}$ 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 areaaky 2,,sf2w ye $0.20 \; m^{2}$ 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/d o7ud ewh45w of 60 m flies horizontally at a location where the downward compone5owd dwh/ 47uent 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 at a constant angular w9sk *,dy od,ivelocity of 2.0 rad/so,dw*,ski9yd 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 and a cross-sectional area ak(z9ko s+lfo*vvz; 7f +m 6p1cr)zmu 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 turn1u/j q 63*nqzhzmv wc.s 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. Eachy2tmmdlp.a84+*su , vm epblgkd7-t 9 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 als a d-, levykmt9 7bd+p4*m.p2 m8gutxis 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 consists of 100 turns .*owck ,l3o.axhug +6 oscyf 3of 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 generator with an output of 1zvn;l+t uy( p 2e29rng2 V maximum when rotated at 60 Hz. 9pr2lt e2gz+nnuyv;(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 wi x/gcr *qh0jpqfy yji.;-d)n+ th 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 p7ju6w-yjqw jh:v98cbp; orxclt-9; 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 resistance of 6.v5jeg/ q0n 7nx00 W. The motor operates on 120 V AC, and when runningv /xn qn7j0e5g 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 qnf r48+f-r w1son 6laresistance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A. What is th-aown 16r8lq n4fr+f se 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. c7 jcg /d-hve8The operating current is 1.0 A atcch /78je-dgv 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 24-V power supply. Thotans 9jk)a4s6j q p 21omod,0e operating current is 1.0 A at full speed. What is j)1mo0 n skaopj ,sqt6d9o42 athe 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 2k k4kzb*myi shl6 m/ib,96b7h fu sm+is 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 in thext1m ; lbzx8x6 secondary. Hmx6t 8;1 zxxblow 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 many turns are necesn(y *o*xax(ehsary in a 110-V primary if the 24-V secondary has 100*yn ( *(xohxea 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 pv4i:np 9m b-)frwl3fof a 500-turn primary coil and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what is the current4 p -mfv3i)rw9f pln:b 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 10+vh1f vqp f/w80% efficiency, how many amps at 24 V can flow in the / pqfh1vv8w+ fsecondary?

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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 a6j6y 2 zom+-k6ag e h7mwweje, neon sign transformer provides 7500 V at 10.0 mA. The primary coil operates on a2-myko6 g7ejwm, 6 jheew6+z120 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 60 turns on its p 1imez6/ s u1xw6 mz3ux.v,qagrimary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what volmsizua g1z/x,qe wm v16.u36xtage 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 +;4 pitsg:fk (h dkgelom va+r+f)/i/60 turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.va;fl/k(or+ eipgf:/g ds+ik+4mh) t0 A is applied 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 secondary h-8q+x4a t rfhhas 200 turns. If the i - hraf4tx8h+qnput 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:3mr wtd* a(92naugqx; /cpcy 100 turns and its secondary has 200 turns. If the input vu*d:329 r;gncay pm(/c txwqaoltage to the 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 1qor9u3l0nxp 1- ym))u 6rib1ld oqa/h 00 turns and its secondary has 200 turns. If the power input to the primary is 100 W, we can expect the power outpo 3)1rlhqpr /0b-i6alyu qoudn 9 mx)1ut 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 voltage is usuallyp++ 9*f d c,sbmu+iyhp stepped up to 4500 V by a transformer and transmitted through a power line of pbd*h+cis y +p+,9fm utotal 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 voltage is q:tr sh7g1nw/usually stepped up to 4500 V by a transformer and transmitted through a power line of tota: n1qr7gwh/s tl 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 zw5*p hodj:5gcurrent at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a powerwjg:h5pzdo* 5 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 a-ztm 8nty76qp: 4 p0z*f bxqiy8.kqsntir,* 50 km long 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 vo *tsx*q, -q6zni8tbk7 p f m840t:zy rin.yqpaltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the 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 5c-i xltpb+* d 0b5mw1iqz5i3e0 km long 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. Whatbtiw5 m l*pb3 -ed50izci1 x+q 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 mvinh8t bsh)exn w7je/w4r4 e . 9m r7t:q,/ulcuch less power would be lost if tb 8/l7 une :t)4/ 74cxmr .theqnwhwvre9s j,ihe power 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 20 A. d.l*e; bjuj;aIt is to be transmitted on a line with resistance of 0.60 W. To what voltage must the gendj. ;j* aulbe;erator 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 lzrbt-srn; qk0l2.ejr-be2 9 of 5.0 A. How much energy is stored in the coil's magnetic j9 22.err; 0b- klr bszt-lqnefield?

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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 inductov d: nr9zt1 kgnsic9ym9i.a*0 r. What is this circuit's ts9yn nc1:ri g.z*avmi kd99t0 ime 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 vohq xg9si-3 0io*wgi5iltage 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. Wupc) *vx81h tasgk:, qt-sje 2hat is the 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 outlet. What is the rl 275 t gh6e34cqzfy4hqxdl (gesistance of the lamp?gy4zhe5f q64l3t( 7qg dhlc2x

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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-V ab fq2 (s2)crns 2axjjh *z2b)yc power supply. What is the peak current through thnsxs 2zqb2jhb2)rf2c*y() ja e 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 connecte69jtd 8 o-0n2+m2it ttqhu jqnd to a 120-V ac power supply. What is the power diss 0tth2+qj-q don92 i 6t8mjnutipated 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 rcmgrwm/n /veru(;31 o 4x0 r;n s dvn5ubyp,-besistor 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 5tq7)0/ 1 ex*d/ntj hfr55kv(zq4 kii vsuej+ e0-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 ro/+uh+b, 6fbyl1 sa lzesistor 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 at zuebvav,vnfqtut 5l3l v95t8,5p,6 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 reactanc7uba fc2m )vl2e of a 2.50-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 14.0 W of inductivehejqm,u /*h5oj6 ;esv 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 neces7ay()gbp l q+wsary for 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 a 60-mH indu:dv-vxf:bv imdbs: j4 t-mk/ m+(9 eqfctor when 120 V AC at a frequency of 20 kHz is applied to it? ib+ ( fm:vb-tvs:vke9-d fx4d /:mmjq

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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 c m6.dh nm /d-y a+.)zzmi;ffmfoil 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 al5ynu km; ouu- 5;ng3p 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 n2la3n0cs ;i txeeded to have 50 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 reactance okp*tj of u1wlb y) j142 68gvap(gaju2f 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-mF capacitoj0 j /ay)qn;:yn gh/azr be 100 W?/);jjyy /ga naqhzn0 :

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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.wps t.ln*z,v k0c9b:hp / 5pldq(f7 pq0010-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 ;3 3 revw:k kn8b,tceuan ac series circuit with 12.0 W resistance, 15.0 W inductv:ecu t83n; wk3br,ke ive 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 impedance at 1500 Hz if a 100-W resistor, 20-mH coil, and(a)mcti-ugfh7r w 32z 1.0-mF capacitor area t7 ihc3f2grw(-uzm ) 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 1.0-mF 0h ;gy wem/xn cv3 94tpurvu;)capaxvcg /pmrw ;ht3uu4;9v)y e0ncitor 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 connected in series with a 20-mH inh;p: ez k;r35pzg- ikn p,)wliductor, what is the impedanczl:n wgh;;r-ei zkk,p)ipp5 3e 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- jj)qs9qnj3h 8 7u;vrmmH inductor, what is the phasejv)sqj h 7mr8u3n;9jq angle 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 cmk6p( b*z:cpxircuit with a 20-mH coil and 1.0-mF capacitor for a total impedance of 100 Wzp* pk:x6(cb m 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 neededbq r c3fhq42d3ww kym3m5xp0( in series with a 100-W resistor and 03d 3bk3 2w4wrqh yqpfm (mc5x15-mH coil 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 inductor at 5000 Hz for(cgvi. 53o0vvbw ai2 y a total impedance of 40000 W?i0iowv( y5 vabvc.3g2

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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 resis6szwhkq.2 ld; tor at 1.0-MHz for a total impedance of 150 kW?zqs6wk2 ;hl d.

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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 wii 1ff g)d(2 a7gmhiv+eth a 20-mF capacitor. What is the impedance at gf(mi 71 gefv)+ih d2a1000 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 a0 6lrf.e fjqeu*o /r:: b0omm10-mF capacitor at 1.0 kHz for a tota:lqe.brfj/ u0 o* omem:0raf6 l impedance 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 capacitopg-ka1 fj,h4 vhe1ze) r at 1.0 kHz for a phase angle of-1kegz1 ,e)pj h4hvf a $40^{\circ}$?

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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 wit9 r2: vopwra 2ro*:bzm 1)zkxnh a 30-W resistor at 1.0 kHz for a totalmn)*rv 1z92wb ozp ro 2x:kr:a impedance 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 capar gm)m/z1wt*dh 3 pclych j*85citor at 120 Hz. What is the phas1jpytrg hcmz wl)mh5**8/3 dce 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 a-t o/z(g uh-z3- ma;t0nevo wot 5.0 V and 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacit -nz-o t0t;(mhzw3a-/oveogu or are 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-mF cac*v g yh)/yjuvow74u(/:dne mpacitor, and a 0.cdwu) 4( g/uhy/n7:jv m y*voe350-H inductor. The circuit is connected to a 120-V, 60-Hz power 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 btybhp1 ijq3 r 3;j34dkl4u+areactance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 6 a+bj;kyurh 4 qldt4333bjp 1i0-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 sg bi/m+2l+f td1now) peries RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected toopibt1m ng 2+flw/d) + 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 necessamoua.xr ,d8rw0 +d1zsry in series with a 500-W resistor for a phase angle of m, zsau08.oxdwrr +1d$40^{\circ}$ 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 = 202ska-tris )1v.0 W, L = 200-mH, C = 10.0 mF. At what frequency should th)vtarsis 21k- e circuit be driven 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 seri4obc mkc+c4h.es circuit with 12.0 W resistance, 15.0 W inductc.k4m+h4 ccobive reactance, 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 circuit v 6 ttnu07klj(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 resistance of 30 W. Wham0i;yze w t1+ b.hw6tst is the power fa1hi6wty;bw s0 .+mztector?

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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 s)pvr*7 imuxzc ghmz h2u2*:- + aombt qj5l.*xeries RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inducto57zq)*.moxz 2vh* g2 + ma-cixluh u: rjtmpb*r, 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 capacito :j/hwgi,up nkc8( ig,z(dy 8wr and a 15-mH coil in series?ikdi(y (,c,hz :gwg8p8jun /w

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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-mFqluk*eh:-(p4 8 s vllh capacitor for a resonant frequency of 10hl epu v (llk-*qh:84s 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 for a rtgk,rc7x4o g )esonant frequency of 74gt), org xkc1000 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 lw:i a o)g8g0iin series with a 30-W resistor and a 40-mH coil if the resonant frequency w)gal0g oi8: iof the circuit is to be 1000 Hz?

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