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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 841m73we8rp suq irm e-qzz3e nul;j(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 states th.1)yl-ytyo iolxb4nlu +b ld2qr7*(7kl8b icat 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 prodl mo* 0 7mcgfpkg9r47zuces what kind of change on the induced kf9glg 0z47mmp* ro7 c$emf$, 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 magneticr q0v z;da4f6v c,l2 ;pm6ugzw field through a loop of wire produces what kind of change on twl4vzpf d06,v ;aqm6zu2r c;ghe 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 hfecwq/m,i/4jbgk mp ut),1 e ), sct8loop of wire produces what kind of change on the induced fmipe4wem / k8, ,c,hbc )gu1qt/js t)$emf$, 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 bfq;qiv2 +br1field 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 ing0 fblh2., l ndda6eo rp26tt)duced current in a conductor will be that which tends d20e2rt.h gn)o6ltb6 p,al d fto produce which of the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A bar maah; 1nsqa28k/t )bk dcgnet is held above its center with its north pole pointing down. The stationqtds)/k8n a cahb ;2k1ary 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 id:f:kv h7*fvbar magnet is held above its center withvd 7hv if*:fk: 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 n kfi5pkdy/ 6.z*be6tin 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 current in this coil as /d *fky5ek zp66nitb. 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 toqgei9xy m (4z:p in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of x9m g:q(y4 ziethe 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 to iechlma1z04r*1u gtju8u m*a6n* n ;vp 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 d6nucaun 81 4jhmmt*ia z; *r0 egl1v*uisappears?

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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-increas6s80 i.dol;j -x sx.g,jycvzg 46 ldbying curriy .cgo04s xgz ybsjl6;x-j ,vd.l 68dent northward. Two coils of wire lie flat on the table, one on either side of the wire. When viewed from above, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls thr -jx kupu8ua4twge5 8 ph/(m-rough a loop of wire with the north pole entering first. As the north pole enters the wire, the induced curre/g -5(pu jkht-8u4 mu8xa eprwnt 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 rotatrel314 knfs)l9 e4h rked at constant angular speed about an axis whose direction can be varied. 9krlne)es314fk 4lh r 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 rotated at constant angular speed aboutg 8 x ag*s6bt2mgdrk33 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 rotation k3ba*6m3ts 82ggx g rdif 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.hn-g* vzyh z1zbx0a; (
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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 thazm7q6r+utdm - (q lr: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 fi.ix( w.2 valjh5p ob2-k -kurield. The $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved northward ateg51.g+f3 yr zz5u hj-nm ;lal constant velocity through a magnetic field that points straight down. Make a statement concerning the potential induced across thfrz5gjua ;+h 1 n-g.lyzm 35lee 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 rot9 9jqx,pv ;zo9oaxce 4ates 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 generatoq/h5tepd iy(*r 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 frequencw6c4 qpw8y i8jy of theywwi 48q 86pcj $emf$ 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 de(x8q(j:4cc,rgk nuxd vice 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 thatxt/e/7 ns v4pt

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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 looq j2nz ddi*,-ups than the primary coil then it id*j-2qd uinz,s 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 thypcqr 0 efsldx878v2:el91uke primary coil contains more loops than the secondary coil then it i1yxq98vs 8lk7eul:0c f p2e drs 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 +k / ol7sjcg dp93b x)jgle:,minput

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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 ci eot(kdgnxcg678 6 -qcno 9j:nrcuit,

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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 axn)/ bid m02m 16x ,rar3ziws )yvhca*n ideal battery of constant terminal voltage. At the momenz3/r, 2dym*6xas hi1xwb ))iarv n0 mct 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 cd/ nr:n:zsur 02klly (onnected in series to an ideal battery of constant terminal voltlus d kl2rr(zn::ny/ 0age. At the moment contact is made with the battery, the voltage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is connected to a z/,glsx t5fngq c0n8au)0ac* n $emf$. 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 w 2 6 zgpgtxqg u2fbod.-.: can,*q*aopith 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 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. Thet2pusmc-i q;5rxtg*d,-n p u8 time constant for the circuit repre n iupdg*pmsx, t-5-t q;u2rc8sents 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 bf4kq2 +*lbh y1m:ygihst5s/ mattery. The battery is suddenly removed from the circuit. The time constantmlyis+1/q 5h * :bhsfgm4ty k2 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 ho/j17 dqqpeg+a 2inb -ave 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 su 1sc24asg3 g4jst+bkipply. On this circuit, the current

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure inductor is connected to an AC power supply. In this circuit, the curr4sa awl :2uz9 )lrxw**e mufe.entwl 2*az.)l*4f xa:sueu9e mrw

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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 the fac3f g;1b4 darrequency is triab 3rgc4 1daf;pled?

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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 inductive / wi7x- al:,ehw)cscpmhlz /9reactance ofzs -h/x :wi /9)m7chcwlpea,l that inductor

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across an inductor appg n *c+es4yzi0vl j*0kroaches zero, the inductive reactance of that cos nvi4 e y0jcgz*0+*klil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. Iu( j/-(qp jrw)w.pp-x. o sjmwn this circuit, the current)s-up .p jqw(wmp(jox/w -jr.

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance in an ac circuit changes by wha0)w.t(-qndc w. mi nvit factor when the frequency is tripnmw..tqi diw ()-0n cvled?

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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 capafw oi*1-2 i8jqx, sfsb7l2b ozcitor approaches zero, the capacitive*78ixq 22so1bij-fz fsl,wob 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 inductor and caid5; -ula4id2e n3ipso0l:u qpacitor in a RLC series circuit0p;3ilad:4e i- s2d niu5o ulq?

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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 ask b+etfxlm5i(m48: zt $\cos M = R/Z$, 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 oo ibni4 (c6hvx n+*u, )tqlp0wf the circuit increases if R increases. When is this statet6)(qnvlh,b*n+ woixc pu 0i4ment 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 bh 12rt/zocr /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. Tvh6m+ q1yuazbagkx120 s) r g*he 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 capaphsj26n/9ib+yx/u 3 ;f wfqgp citance both double in an LRC series circuit, the resonant frequency of that circuit wif 2f/wgxu9h sb+;pn iyq3j6p /ll

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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 AC5 0tk a) if rrvg)y0h)dnz9(th 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 ctoy*d;8ocyg : ircuit 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 unif u,gfd+z9f qi. ;(ped*i1livsorm magnetic field of 0.20 T. Find the magnetic flux throu1 ds ,f uidp+vi(9z.*elfg;i qgh the loop when the 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 0jtj-9ng a bdkug:r.*;8 5qno f.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop anj dga .9 r:ftg8q;nj*oknub5 -d 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 ik:0lml2f2j2kw wsbu ( py77mc 2z5l io8qcb8 yn a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vectobq7l 5(8wm zulopw i782 f:2sklyyc0mk 22cjbr 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 frokz5 sx5d bz1p,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 coilid+wdj (jy fne.up/3f 5ny.6t79bmzxvk1 +yh 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 turns of wire on a square framef5q vr2- doo,ci1pi 9z with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field chan -i o dr5zipqo,cfv921ges 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 tug 5 mbt-iu;a-srns 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 apb f:ok4;k u.xrea $0.20 \; m^{2}$ 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 j7d +if axqry *ot/55w60 m flies horizontally at a location where the downward component of the Earth's m fw/xoraity575j* dq+agnetic 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 constanth2yw/eg0/mk o angular velocity of 2.0 rke h gw//2ymo0ad/s about a vertical axis through one of its ends while in a constant magnetic field of $5.0 \times 10^{-5} \; T$. If the magnetic field vector points straight down, what $emf$ is induced between the two ends of the bar?

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65#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The coil of a generator has 50 loops and a cross-sectional k)3*oro 3fzgl area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns of wire of area xi64s 3goxt w7*9fqx1 liy0 yn+fyto ;$0.090 \; m^{2}$ 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 rectanp,ghztj(v , /fgular 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 ro, (f,h /jpztvgtates 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 consists of 100 turns of wiryb3:mq8e/lmrn .* fnj e 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 a fi06hok26:0ecrq udgn output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T isedrc6hfo0:i6ku q 0 2g 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 generx6n/xpj 1k dm7ator 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 dy,h +r1fmb)v motor 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 resistance of 6.00 W. The motor operates on 1b wo*/6jk7 sfm20 V AC, and when running at fuljm*6k7wbsof/ l 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 internaj-bd1- gc-cl8rjj kf 3l resistance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A. Whatl-d-rfg1 bc38j -kjcj 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 6.4w(vrfi pat l3 nf7l5 z5 j9dt0s64pxy0 W is connected to a 24-V power supply. The operatin0 lv ij5tr dta 7nly(ws6p43f fxz495pg current is 1.0 A at full speed. What is the back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W iy b9r*min 4ay)s connected to a 24-V power supply. The operating current is 1.0 A at full speed. Whany*4ryi b)m9a t 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 isisih whtip*0 w3: /f7q 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 ofpj (t u, l* sm;tsev(rtdmsd+.(+ mon7 a transformer causes 14 A to flow in the secondary. How mat m upt.s +o t*sedvd+(r(7;(lm,msjnny 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 mapkiuo-:f ghq.3m *r5wny turns are necessary in a 110-V primary if the 24-V secoqgr5-3o i:wum fhk.p*ndary 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-turnh65/ hnm:oe v1ovs-dx secondary coil. If the curroh 1/d:v-ehox s6nv5ment in the secondary is 3.0 A, what is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primary of a transformer. Assuming 100% efficieyv b1.wah zj -)pd8a hy/g-im6ncy, how many ampjyh.ia)y6w -/ba1 hvp 8mz-gds at 24 V can flow in the secondary?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The secondary coil of a neon sign transformgrn46doo8 ;3pqsiy w7er provides 7500 V at 10.0 mA. The primary coil operates on 120 V. What does the prim; pyso67g8d qn3ow ir4ary 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 onur 8/qh *xo bp/1+ddiv its primary coil and 300 turns on its secondary coil. If 12/b*+vx8 r i 1podqd/uh0 V at 2.0 A is applied to the primary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on itso rn)1b* ht(sxzt* /t4gij) tw primary coil and 300 turns on its secondary coil. If 12)ji)b1gr *ztw(4sttot/x n *h0 V at 2.0 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 secondqek2)4qe+x yl ary has 200 turns. If the input current at the primary is 100 A, we can expect the output current at the secyee k+l)qq24x ondary 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 secoohna8 rghyb ed2y5*/+9x8zckv(xzd 5 ndary has 200 turns. If the input voltage to the primary is 100 V, we can expect the oyd(xy ex8zb5 k dh5/r2 9c*ovna hg8z+utput 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 turnsv oh;(o)m65naihb(s v6yw8r k and its secondary has 200 turns. If the power input to the primary is 100 W, wynrb6wh5om8 ;i( ( hsa)kov6ve 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 of current at 120 Vl0qvmic. t03y . The voltage is usually stepped up to 4500 V by a transformer and i y30qt 0v.lmctransmitted 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 16fs1rwrg .f7)syoiqi 10pzk2 20 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line s10)q6prsigo7iy f 1w 2k zfr.of total resistance 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usual.8y yrd6(qirciej;t0 ly stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percent (0etqji8yrri .dy; 6cage 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 gener0s / r,giucj3sator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is step,ssjuc ir/g30ped 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 50 km long has a total resistance of 19zs7u 3kzu zu0.60 W. A generator produces 100 V at 70 A. In order to redu7z u1 u3szuzk9ce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6.*t.1(bnll 6v kp7vt)0 vnvtzhpk ;b 3f5 ekax-W line at 1000 V. How much less power would be lost if the power were transmittkpe3 ) vnpnxalbvk*zl.h;(v 7tt.f1 tv0b 56 ked at 3000 V instead of at 1000 V?

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93#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The output of a generator is 440 V at 20 A. It is to be transmitted on a line wqij kjlt)7+ cz+2:dmfith resistance of 0.60 W. To what voltage must the generatoij)q7:lj2+zkcmdt +f r 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.few3qt b,y/8 p0 A. How much energy is stored in the coil's magnetic qy/3t8f b,epw 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 re. q-bw. tjv4anzae:, asistor and an 18-H inductor. What is this ci,q :za.vw4-ba e.jan trcuit's time constant?

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96#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the peak voltage in an AC circuit where the rms voltag06 )sabxrihk50 8 fzmje 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*rb7 w5p9nm (yed)ja u 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 place5lco*),g)pndu)hoia l8q g( f d into a 120-V AC outlet. What is the resistance of the lamo)u )5o*,p )acdgghl8 ln(iqf p?

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99#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power sup ddi 9gcn6u(.lply. What is the peak current thl 6cg.i( dn9udrough the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply2sj7 2 swhb 0ba(rb3ju. What is the power dissipated in the rbw b2 s72 a0ub3jshjr(esistor?

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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 v -a o3lfj-dm1is $I = 0.80 \sin (240 t)$. 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 resisg i6 j,ya0 cklx)8-j45 w+qsmc)ol rkator 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 hu. iqgy -x2-lnf.c :va 50-W resistor 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 reactancei74gwfz d3d*4mek5 zq 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 10q yt- iespgc2x)s zr -uwa88 kkg-93.w00 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 inducw;si)0y)*ffi ve u6ejtive 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 ofh(k u8l.ccd5 :rol z va7dmq -ijy.47r 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-zjn9- 035cadibd/x:gmjpo 1 hmH inductor when 120 V AC at a frequency of 20 kHz is appliedh0p na jdob :dc/m1ijz-93x5g 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 a 11/f4z h)mf*w cm0-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 oks6m2b , 7hlxsf a 4.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is needeboyv yz)0k 7tw i62a83bf fv 8urlyq;+d 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 0v)mui .lopr 1reactance 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 capaciti.lgdee0) tf(o,ol9 xb ve reactance of a 0.010-mF capacitor be 100 W?lex,9f dg.)too (l0eb

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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 (3hhv, n wpv6aHz 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 circuit with 12ca01 p:dogj/ b.0 W resistance, 15.0 W inducb:10oc/ jpdagtive 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 impedanc7ttvduvu75a)0 j: 5pb5 tqqcce at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capaci05v5a)t: dc7p jt7cq utvub5 qtor are 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 1qs8yz 2j6knr.le b..6q1q bzp500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are conne.lk6z6bqbj 8n seq2.z .pr1qycted 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 inductor, what is tt)i /y/p (4d u0hrkdyfhe impedance at 10 u4h 0kptf/riy)d dy(/00 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-mH inductor, what is they h56e,z jyoom7lg2,)vzs4r i(ahr d;twj: 9t phase ahlt) ,vmy;jwh ye7, :4rt96 jozsdog2r5za( ingle 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 w z la)e/0u.zdeu7vi) circuit with a 20-mH coil and 1.0-mF capacitor for a total impeda)v7a/ .uze zuw i0eld)nce 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 capacit8r koao p5ok7ur ,h/f6ances is needed in series with a 100-W resistor and 15-mH coil to get a total impedance of o6a8p,ror7o5/ f khku110 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 Hzp dmuq 8*si03b for a total impedance ob*0 3qdmpi8 usf 40000 W?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in serie-dh7c n fxms5mqc,v, dr.,nq. s with a 100-kW resistor at 1.0-MHz for a total impedand5dh v7n,x.fn c src.-mm,, qqce 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 in series with a 20-mF cv y5; -otqg(s+pnaa4 capacitor. What is the impedance o-g;a 5c 4sa+pyt(nqvat 1000 Hz?

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125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-mF capacitor atlos5wak yu+ y:p sblqy,m5th, ,2dzwytf78 2* 1.0 kHz for a tota yt,uyq l8 2,az syb td+m2yf,khs75pw ol*:5wl 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 capacitv ; ,xld ,bpyx8ulde-5or at 1.0 kHz for a phase dx,ylxve d8bpul5 , ;-angle 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 :d +wo.ioj+ sukHz for a total impedance of 4oidu.soj ++w: 5 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 120 Hz. What is the phaf 4 ai(z9dtja i9awu-*setf d(iai*w-ja9 a9 4zu angle?

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129#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows at 5.0 V and 1500 Hz if a 100-W rj5y 5w6 q5;ypa4plzxeesistor, 20-mH coil, and 1.0-mF capacitor are connected in series 55a zw6p xle4jqyyp5;?

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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 resajztm5m nv oq0b1)y+b4w 5 dnplf3-+kistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power sup nyw tpav+3jf0knb1z l4o 5m5+qd)b m-ply. 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 capackb*j;oy4 a s)a5b*c xiitor of capacitive reactance 30 W, and an inductor of inductive reactance 30 W are conneaiyo *s)bx54*kca bj;cted 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 containo qg mb)4rcu(ix;,gy:ing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power suppl(:b xg; qg)4ru,oyc miy?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W resitvn6di4mzn qa2* x), hau1 z0nstor for a phase angle of )qm,xun atnv10i 42 da*nzzh 6$40^{\circ}$ 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 (y1 7xxn :ku3ym 5;jcp hg6ocf= 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferred from the driving sy mofc(c h7u 1 nk;:j5x6xp3ygource?

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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 12.0i* b:f+tb; gtj W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance,tbj t+ bf:i*;g 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 circp0 d xr1ycl r9jo:hny.. km29uuit 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 0kpaleu900c ol)i h mfl 2f8w*hj 69aaimpedance of 60 W and a resistance of 30 W. What is the pole am90hj 0cpla h)6 9 ok0fawi82luf*wer factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series R bc8;8k esgxrec(+9 6rh o-nswLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to6 8srbc nr;h-s ec98wxg(ok+ e 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 a fa3u y+ctfb)h )bg(-8q;j20nkwqy- uzt oj(cnd a 15-mH coil in series? qo+ty(;h zb(03-cj a k8n-fw)tqfc)2bjuuyg

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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 cu pb.god1f9a40c2 gt)y nbgt /apacitor for a resonant frequency of y o.ft1pg9na0)u 24btbgc/gd10 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 3j9rdt2hqg fy/5 s,)3k5 to1tufamb6x.7-mH inductor for a resonant frequency6)ak b9qtytd u 53,rx jgsf/hof152tm of 1000 Hz?

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142#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor must be placedup hm4fv,j7,u in series with a 30-W resistor and a 40-mH coil if the resonant frequency of the circuim4j,pfh uv ,7ut is to be 1000 Hz?

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