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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 unitxo z*wwmw6s/7s of magnetic flux except

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction staxlt9*vbs. j s7tes 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 c h4 bzqp2cd.7ihange on the zq.p47dchib 2induced $emf$, 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 pm,34 tx jl+2ya)hfc-dj hs gqq632bv field through a loop of wire produces what kind of change on the inducjqv4h2)bh2 s-d6jt ql+mg , 3xc3pyfaed $emf$, 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 op9spx5wy.b y p2z17kb f change on the indu .9bkzbps7 w5p2pyy1xced $emf$, 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 removedy2zpuo u .4x:e.isris w7 x7:u from a magnetic field an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's law, the direction of an induced clw; xo69b 3ga(+eidegurrent in a conductor will be that which ( e x9lgi+6e;oagbd3w tends 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 bar0- 8ep pz.wamx magnet is held above its center with ize 8p0.awmpx-ts 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 barg;l(*n/ lxgma*.e gwz0f (n/ mg; jsll magnet is held above its center with its north pole pointing down, and released. As it appronznw. (/fgm0e /*llgj; m*; llaxgs(g aches 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 in a region where the magnetic field vector0dvp:lbdg ;vv* fb 6. grvkb.* points straight up. The magnetic field vanishes suddenly. Wr*vvpbg: .*vgd fl06vb; kdb. hen viewed from above, what is the sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top in a region where the magnetic fielu9m x wh73lvf:d vector points straight up. The magnuvhf7w 93x: lmetic field suddenly grows stronger. When 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 table top in a region where the mag:rdz1,/ :ici pnuzq5 lnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, what is the direction of the induced curre:,dc i/znq5pu i :lz1rnt 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 li3m hzlu,5:l n r+dly n-wnf5d-es 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 above, the induced curr lfd nd,3w-5-num: 5yrnl+zlhent 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 wimcd3g2 ma wr0ia,j2 )xth the north pole entering first. As the north pole dmj a 0cirx)32amg,2w 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 wire is rota7 3g0l3-jmk f3vqquvuted at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, wh3quqvuk7j v3gm3 0l f-at 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 rotated at constant angular speed aqd69znh: j,e hud p;m;bout an axis whose direction can be varied hd:nzj6d p eq;muh;,9. 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 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.z-wpj+/ l/flj1- v5wqm(of iw
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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 thaslrj7-;6akl,lqf+koz; m -k nt 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. Thepjd -qs z4-nv: $emf$ 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 ,fmm eulq(xi5.y1 0 upin the east-west direction) is moved northward at constant velocity through a magnetic field that points straight down. Make xe.yp15ulmmq0 uf(i, a statement concerning 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 r,u jclaq rsz/i1ncb mle 819::otates at a constant 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 generator4t28win 5j1 hi8rpta n 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 frk9ch/k xl6c: cequency of the /kxk6cc:l ch 9$emf$ 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 do((/)oi54ajig- jrqwuum l/-px/ r fc evice used to

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26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A transformer is a device t/:o f k(ed 8u4sou*99qiieamfhat

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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 lo2l glrjf+t3)m/qv w+-9- c*bpzfej r/c um-ofops than the primary coil then it is ab r/cp-mjl +f*czv+/2o-9wjf )r-tfmgqu le 3

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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 exgq lsy.bq)n 5yv)s5p9.a*g the primary coil contains more loops than the secondary coil thsaqy5lg*vy5p x)bqne9 gs. ).en 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 hrhut/aoe.8jsj7 /u 6 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(yuy s1o/ dh43xcgbk+j k-9z o circuit,

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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 i-(kxlur,qo wj+m 1l8jdeal battery of constant terminal voltage. At the moment contact,wjo1(m-l qrjxk8u+l 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 connectedm txy:n; m6wqe+e t: rb/jmj-: in series to an ideal battery of constant terminal voltage. At the m:mm:tx;e +y nw:j6mje/tb- q roment 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 s 4mj80yrdhsi5zg,6 f l3x 5wzwith inductance L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the inductance is 2L. When it is connected to the same $emf$, what will be the final value of the current?

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is connected x3/b lyyh3kdxe p 29;ito 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 const-obdnoj ;/q j-ant for the cq-jn;/bodoj- ircuit 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 is(vv0wv daa3f9v uld7 qcwn-6hc.8 x+w1k6vhz suddenly removed from the circuit. The time constant for of the circuit represents the time required for the current vua7 n6 3wv0qafklv.x w6hh+z91w c vdd-(8vcto 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 m3zyje2wsy4u- 7ia r8same 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 po 9w:zh8aw pkh7wer supply. On this circuit, the current

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure inductor is connec+1. pk wlin3gcted to an AC power supply. In this circuit, the currentlgp.+1ck i3wn

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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 6l;y29fu n peuxsv)19yvd* yl what factor when the frequency i;s p*ex6uul )yn29l91f vy dyvs 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 odcm) 8ybng 0pafr59(inductive reactance of thro)gdy5f m9a (n8b0 cpat 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 approac1pl2f5txy) y-fjc )zkhes zero, the inductive reactczp2yjlyf t51) - )xfkance 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 l 5 k6spqn.wbd)faf9 9power supply. In this circuit, the curre 96f5q9wfl )n sdpbk.ant

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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 changes83z6qi7:qwm d p abz8lc d:vlq-nd :u* by what factor when the frequency is uqdzdv8b8l- qpmni: *d: z3:q6w7clatripled?

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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 v azz qz 3vkq1)a1i483n :bhhrcapacitor approaches zero, the capacitive reactance of that capacitorbir v34z38ak h n)11zh: vqqza

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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 betweel6jhet 3-+3 z-q hyx9bswqurm4 s.d;tn the voltages of the inductor and capacitor in a RLC series circuit?dql h;6hmj-qewt+x 4-z.9u3r3sst yb

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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 defined as a, .pj(p-xgri$\cos M = R/Z$, 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 tkpbm7j8 ( uj1of the circuit increases if R increases. When is this s7j 8pm1 butk(jtatement true?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the circuit coiq2m/ ya1noui*2/a 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 i/9x6wzii;se6j6fys.r oj p v)mpedance 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 an09gtg 7uebay*d the capacitance both double in an LRC series circuit, the re7gb0* ay tg9uesonant frequency of that circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is driven by an i:01o56lfqarws/avc 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 occursism rjtb/t;-325 3tpumojh:c 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 maa b40p ro:zim+gnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the l40ia rm:pbzo+oop 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 y/ iy7agj9e0jzp/2 pa rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the lo ei yj/p9yapj0a7/2gz op 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 field sej;h-w0yu8d x7z/t q of 0.20 T. Find the magnetic flux through the loop when the 8t;se0 wxdu j qhzy/7-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 loop is red4,mu0i mu6)gzb l3bpn ur(rp4uced 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 chanuauz /)mxb5e- ges 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 turnst y-nh/l i.3aq of wire on a square frame with sides 18 cm. A uniform/yalt3-h i n.q magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the 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 1(oo q2m(v 5ckgushy ; cod+7p95 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 );dto 85e(x:qri xzxhand area $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing spl7k djjp 3wpy-1x0gd vj:o4)axrlg,o vj7 . /kan of 60 m flies horizontally at a location where the downwar3xd jj)l. kp v4j,7 7ajdgy 0kw-o/lpro:vgx1d 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 that is 2.0 me nnww, h.mmk.z.2 1xloln,w; long rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while in a constn;zm.h ,ol e2w,.nx 1lmk. wwnant 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-sec jnhn0zp9*luyv x17v*rft) t5)jibd3 tional 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 .gpxh) hd b/cwv8cg+.nmi 5d- of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 rectangula(yop6d: epg u;r loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpeoe;(up6 dygp :ndicular 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 consicwq s(q lse)/-sts 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 wish to constrwbtj3tv3v):+bcapb o+,) cr euct 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 the area of the rotatinbbbc 3aowv)jr+,v3pc t:) +e tg 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 /ip*(m l8i) 4zwjfusigenerator with 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 m+4e86: mlsoptknv2t kotor 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 r e.8, 4usrhp4xdzo p,vesistance of 6.00 W. The motor operates on 120 V AC, and we p4vxr .hzs,4pu8 ,odhen 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 connectedcls6o bp7- 0xtx zqi;8 to a 24-V power supply. The operating current is 1.0 A. What is the startzqb ;ix6-ps8oct0 xl 7-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 plhr8 l;6tzx/z j2iy c*.fq1f W is connected to a 24-V power supply. The operating current is 1.0 A at futy z6r lqchfl*1.px/ j;8zfi2ll 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 t;wma l3l2 9saep7ai x(oejr82o a 24-V power supply. Theep (wieajall;792s83o 2ra mx operating current is 1.0 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 needed to reduce an9k k7r eu2v6a 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 the se ;q z1t0i+y+xl y l.9epi6vvbicondary. How mavy+v;1 qylixtizb.9p6 e+ 0l iny 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 nect/, qhr rv5l4*q upy/oessary in a 110-V primary if the 24-V se5rq,o/ tl4y r/qh p*vucondary 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 primary coil and a 2000-ky z)3pymajp:85 /cc qturn secondary coil. If the current in the secondary is 3.0 A,y8:3zj ypkcp5a qc/)m 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 transfoocb:c03czk. r )b 3cmormer. Assuming 100% efficiency, how many amps at 24 V can f03 o r)c.c3bzbmk c:oclow 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 sign transformer provides 7500 V f ov)yx*9vq;a l.o6 pzat 10.0 mA. The primary coil operates on 120 Vf;ox)laqyz9 .v *pvo6. 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 primary coil and 504mc,a,id 0n6fnsbxvg a 0p;ngt cq8 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, wtabdf0804m;cng s0g6,n 5,q v nxciaphat voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its priq qb7m9/mkw (emary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary(mm bewkq /q97, 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 has 200 tu+hltt4u+./.+t8 erm 6j/+y pbm eci.kdgk hyzrns. If the input current at theembkyr.t/g+8+k i+ h4c/ d+ h 6y.l.mtpjztue 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 hakv)o3j z7 b7nj bfi(1gzc4qh 9s 200 turns. If 3f7)1hz 74bjbogci v9(kqz njthe input voltage 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 100 turns and its secondary has 200 tuf1 ietndo13+k p+ jf/wd tp2e8rns. If the power input to the od /8teje tki +nfw2f1pp d13+primary is 100 W, we can expect 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 qq3tgm0ei;t; 8 x s2bsof current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted8qgq;es2bxmtt;0 3 is 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 qd-n0 i4ifow x3ka(zhm/29e mvoltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of to0f hx9a 32 q( -imwi4emdn/kzotal 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 produces0l 01 gzyvt9v jhgo 5r9 m8:tzq +1nuu*uj2hye 60 A of current at 120 V. The voltage is usually stepped up to 4500 V byvo2: 919uj+z y8 hnvmjgz ul0t1*q0 gehyt r5u 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 has a total resistance of 0.60 W. A gllkc/a- o1-n +hqnm0senerator 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 thm1qlc/0-+ohn-ska nl e 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 lin(xy; dh0acf9le 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 voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost whenl xh(fy ;dca90 the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W line at 1000 V. How much less power would beqktmdk,u5ukq-gz6ggay :q*ug i4j*r :c z(3; lost if the power were transmitted at 3000 V instead of at 1003zg:rk m;:u4(5cgjz ,kqqyag6uq-* *dtuikg0 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. I3u 7ywf1rzh; q9vbrk66s/n omt 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 tramr/6bvfyko6 1 wn uzrsq7h 93;nsformer 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 curn)jgfwh dc(00u )thq 3rent of 5.0 A. How much energy is stored in the coil's )ud0g3fhh 0)q(tnjcw magnetic 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 9zqhwy;z o6 e9*sne,fpji vv1 )05a xxan 18-H inductor. What is this circwzoa1h ;ni)0 f,*e9vzx qesx5j v96pyuit'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 ACqcdp;,add kzs;r 6s ls85nh06 circuit where 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 120a,cu;vspx / f5-V AC outlet. What 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 inwn o(upy/:v;o d +z72ycr5 t*s9figo 3kecg. dto a 120-V AC outlet. What is the resistance of the lamd*t7 .c5 e3(v+ uprgf; i9o2 kc:ygn/oy dwsozp?

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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 -ua(z9sa* j v)q48rt y6ydepw120-V ac power supply. What is the peak current thvyea j9dt*)4( 6aprq zwy-u8s rough the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac powhg j0lh*w1s q/er supply. What is the power dissipatj/ h1l0wsh *qged 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 resistor i4v, hikc ;)bdlfg.qrro: ri/) .+dqzbs $I = 0.80 \sin (240 t)$. 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 50-98b h8,4unyqf i o5vplW 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 resi -i 2wz4ylx*wys .wx6,t;n* wsnh0oj xstor 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 v*6xk6* xp lp0s46.sh qfykbl1.0-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 reacz0 eg yyoo9q7 0dx4swg sn5z3.tance 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 inductive4 uhw.yur1a7g reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 157 W of inductiv4twkei:et1,)3 gig ,jzfyu fl1n) ,tve reactance at 1000 Hz?

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108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH inductor when 120 V AC at a frequencp iss j8j)k*6ey of 20 kHz is app j sp*j8se)ki6lied 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 throug -.y1xlzstov9 psh.;rh a 2.50-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 capacitor at zms-kp),e9j g10 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 todkwx( mxl ;-j;g.-iks 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 cd3sp**west5da n5f 4a apacitor have a reactance of 1200 W?

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113#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will the capacitive reactance of a 0.010-mF capacitor be 100 1dmmb9 v0rjod(ut m: -ceu2+nkpx/f / W?fbo +exmj1(2/dctuk n mr m0:udv-9p /

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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 1000 Hz*akou2vvt0vds3 9(s tfo0l)p 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 o8 -j0p/ceyxuprr i c:*f an ac series circuit with 12.0 W resistance, 15.0 W induc*yeuci:/r0-j pp r8xc tive 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 ckfp p16mm1 ,bHz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are conc1 mpb f6,1kpmnected 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 rb 08brde vgj1c3u5,.uw7 xmjif a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connec85g0d,bc3bjw rmjr vu u7xe.1 ted 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 conn y8hd2oe 2wv/nected in series with a 20-mH inductor, what is the impedance at 18/nw od2y2h ev000 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-nwkuebm .w +se2kw(,0e ifdzixt))vu* 069i m mH inductor, what is the phase angle at 10)nee(i.imuvw,+u w 2x)wi m90z0s 6bek* ktdf 00 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 n 0q,fuqs0 muvnt6y3c +eeded in a series circuit with a 20-mH coil and 1.0-mF capacimy0f +u,6v qqt0u snc3tor for a total 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 capa8ymi15 y.tr vdcitances is needed in series with a 100-W resistor and 1ymdtr.i1vy58 5-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 pu/.t76c6.2 trd rj*twyo 8ymulvteop8 t in series with a 450-mH inductor at 5000 Hz for a total impedance of 40000 W? .dowyr.et6y8 ot*7lv/6tjru tpc m82

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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 with5(i /nt7pu)mujz4 mo e a 100-kW resistor at 1.0-MHz for a totainzut7/ume 45pmo j()l impedance of 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 i2hlfhfjm 1ud-:;: koyn series with a 20-mF capacitor. What is the impedance aok :2fd1mf :; ulyhjh-t 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 sy p)mec95y15 wwu;b4ehq;omuq ec4 -series with a 10-mF capacitor at 1.0 kHz for a total impedance of 45 mmpcqo4b1s e;ywe5h4 u5- qw uey;)9cW?

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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 u.f (zfi-sg::fai -/wf g:6:li3iwwwu nbl2a kHz for a phase anglufz2wfn g:w ::6-(iglisai wl.bw3ffia/u :- e of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1.0 kHz fori r63h91kjzbb a total impedance of 45 W?b r6h9k1 bji3z

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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 s/+h 6parnxf5xfd4i 5 ,i0dglveries with a 100-mF capacitor at 120 Hz. What is the phase anglx d 565al/,rx+inphvf0 gf4die?

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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 5.0e- 9/pudqm .hmw, 3zli V and 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0hdule 9 -3 m/im.qwp,z-mF capacitor 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 res4im hcm3e*7ljt 8gh pbh.u97eistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power supply.*7bm7 c ee8g94h j3lpm hhui.t 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 capaci*dsq90 0v)13fz f oss2mgsqeqtive reactance 30 W, and an inductor of inductive reactance 30 W are connv sso0 z*f123sqs e)g q9fdqm0ected 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 circuit containinghvho . vi,v0y) a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power vo0hvi. ,)y vhsupply?

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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 wi/matrvdn;m 6sozfn2.l pb.) m(fb4:qth a 500-W resistor for a phase angle of /l nnr av ;dt.)pfom:b m.(qf2s4bm z6$40^{\circ}$ 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 whsna py/eb28ikh t cm3ou96*h 3at frequency should the circuit be driven in ordypbt cea3 h2/k*os 3nh698muier 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 resisxjm stnbhf 0+3*m, f.hg4 6suwtance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is c bwsh+nug4sm ,*0f6 h3.mftxjonnected 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 circuitpox3w+d9ty, z 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 i o (u/olwkg(860 W and a resistance of 30 W. What is the power factoru/owk( o8gi l(?

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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 resistor, z)j zcq(mg6v5a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60( c5 m)vzzgjq6-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 frequencytm 8mc4d w6p+t of a 1.0-mF capacitor and a 15-mH coil in series?p4+86cmwtt d m

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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 for a resonant fw10.kug lmrd:w*obie y4cx:, requenc d.:k ub 0yxor14g*wwcilm: e,y 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 inductor for a resonant hmyiia(.,/j:7/gc h ty p)ggy frequency of 10/.it( ,miggphyhgcy :a)/j7y00 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 ser 3zv;9+6ln oowg6jix kies with a 30-W resistor and a 40-mH coil if the resonant frequency of the circuit is to be 10z3 ;iwo l6jvo+n 6gk9x00 Hz?

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