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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 of mspz l5 cho:g8/agnetic 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 that the .tmo psp:un t/if -w,8hn: hj*$emf$ 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 sw;dod9pg-,f *+eavm a coil produces what kind of change on the is -gvfd ;e,p* a9wd+monduced $emf$, 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 ely8qq 7+8an mmagnetic field through a loop of wire produces what kind of +qae 8 ml87yqnchange on the induced $emf$, assuming all other factors remain constant?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the diameter of a loop of wjvbduge7aq/ a1 9743 sen6yabire produces what kind of change on the induba6a7 jn4 dy s719qbge/uae 3vced $emf$, 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 fieldg c* 8qeq7(wvs an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's law, the direction of an induced current in a conductor wi ccqh xig,jq5 ysq)l,:o1brf/ 9)mx b;ll be that which tends to produce which of the folxbb;y5qj,q c))1 mxi9rq:ofs cgl/ h,lowing 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 horizontawcc+l3 eum 3z/9vv5/yb pclom(4:8 k7qzuviy l table. A bar magnet is held above its center with its north pole pointing down. The stationary magnet induces (when viewed from awup+ /3(4zb87 yuc5lk3 qv vo c:il9/zmcyve mbove)

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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 held awrzh21 j7 ;:u i:sfadnbove its center with its north pole pointing down, anw s2rduh f;z ja1::7ind 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 in a region where the magnetkr0yfqm+6qw k)f 75flic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in th0 5qfwmfklf r q)+67ykis 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 h21lpzrc4 gr, region where the magnetic field vector points straight up. The magnetic fierl2 cgz r4p,h1ld 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 th7q*aq- z-nc(, kob xlve magnetic field pon,(c- lk-aqxvz7q *boints 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 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 horizonta m7 rrbb)f *iilf5/j4ul table and carries an ever-increasing current northward. Twol /fmfr r5ii *7)4jbbu 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 through a loop of wire with the north pole enterin: t8vv6h aod3vg first. As the north pole enters the wire:tvhv8oa 3dv6 , the induced current will be (as viewed from above)

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angular sp vnq0j:gyvfj 6 94gjtf/we0/ieed about an axis whose direction can be vavj9y0etn/4jg qf0/i6jfw g v:ried. 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 wird v lf4u345abjj-m l9oe is rotated at constant angular speed about an axis whose direction can be varied. In a region where a unifb5f 4laljo-d9j mvu4 3orm 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.fl c9 ;y/n(pl;ih5kdjsmw y:(
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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 tha8tf ylwpgr 95g6 s)(nnt 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 ma*ghfc+j -awqj4x.*cfm(-7a ,n ghz ssgnetic field. The $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved northward ;t87y4 hxfps,yz 6cyvat constant velc xy p;4fzyt6,hy7sv 8ocity through a magnetic field that points straight down. Make 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 rotates at a const8b :rwd9e n+roant angular velocity $\omega$ about a vertical axis through one of its ends while in a constant magnetic field B that is directed down. The $emf$ induced between the two ends of the bar is

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23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An electric generator transfo -mtui2:5ats srms

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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 frequency ofcb3p bff b+o/(p5g)ey th3yf) bpp+bg(obc 5/f ee $emf$ 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 usjsu8/,4yjo mtt/ i f)ved 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 tha(gzg z60)neo 3yb9lgwt

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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 loopslh9g17-(uhm su0;mns3v;( ay pfacdo than the primary coil then0hoyg umu(md pv;s9n;1shf7al-ca( 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 loops than th vwzsvb5 *9zm, pvrbc6e6 c,r*e secondary coil b6zbv, z*m*6evv rs59cwcp,r then 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 inpu7 bm:igs 2jfxtq3 *nt4t

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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 circu8q ee r v/bs y-,+gqzirot6b(*it,

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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 batter9raaw 4vm 62oqe ;t;zky of constant terminal voltage. At the moment contact is made with the battery, the voltage across 2am raw oeq z;6t9kv4;the resistor is

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to an ideal battery of co4elqat6b f1 m5hhq*2p nstant4mqhhb6lt eapq2f *51 terminal voltage. 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 z+ykh.sly g (*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 Lq53525gsr qkrasyf39;k5t9n w nahgu 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 areeoh draq0;ke/1 .gl v,jb+s0tzg(nsty f8* :n connected in series to a battery. The time constant for sad(jf /t8s k*r1tv,.: n zngogq0e ;0lebh+ythe circuit represents the time required for the current to reach

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a battery. Theww vt.b iut,4wy;) 8cu battery is suddenly removed from the circuit. The time constant for of the circuit reprev ;, ywbttcw 8iuw).4usents 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 have the same u +p+lma(dj oq-nits 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 tou.( ehbjcj-ni51 g3ct/ z,3k+k yeq or an AC power 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 connected to an AC power supply. In this circuit, the ssdbuqo o05 3e2)9 wgmcurrentue0 og) 92o sqb5w3smd

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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 byxv5wf9x jg sp1var ;z+.k8 v3c what factor when the frequency is triplw zp savxv;38x5gfr +91c. kvjed?

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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 doublfq+wk;evz h,f;c kv3 (ed, the inductive reactance fqv k (vz;w+efck ,3h;of that inductor

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage ak7e+qao+lb .2 jj )yj nsl.ho(cross an inductor approaches zero, the inductive reactanc 7.o)ln.+qsykaljh b+ j(eo 2je of that coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In this circui;d: sn+ 9gyvmqt, the curre:sv ;n9myd q+gnt

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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 what factor when the frequ0hi xihvl q 5e8w e/.z5i /taq;ln6d+fency iivnd.8;f 6e5az/5+ltw /hhq0elxqi is tripled?

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across a capacitor approaches zero, the capac1 zs-qqj 7m-uoitq q7omjz s--1uive 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 capacitor in c 1vdmwrz,zap.oj/89 / +g vy/dxa6wja p//gwm89.xjyaz o/r1v v, wa 6d+dcjzRLC 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 p,fthk -3ev9yan RLC circuit 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 impeop aapn ;d:t+u7f/a 5cdance of the circuit increases if R increases. Whenn/tc da:u7;p5fp+a ao is this statement true?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the ci(i2clzi f3;nxrcuit increases if $X_L$ increases. When is this statement true?

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50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC series circuit. The impedance of the ph67r+ o al2k ao0gjn;circuit increases if $X_C$ increases. When is this statement true?

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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the inductance and the capacitance both double in an LRC series circ,v v-r(+d tdowuit, the resonant frequency of tho(rw+v-v,dtd at 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 circuyao;n85h njs;k a3:zuit 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 RLC circu 7om (r57ythmr;ai xv)it 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 radia1axzio6dx .8us 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magneadixaoz.1 68x tic flux through 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 0.10 m is rotating in a uniform magnet7 dzrgdo62 oud( km.c1b:(hy fic field of 0.20 T. Find the magnetic flux through the loop when the (c(y72kudhd .1:fmd oozb rg6plane of the loop and the magnetic field vector are perpendicular.

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57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating inajd79fiy;7jkyy w+8hqh *pl - a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the pld7lkj9h7 y a yqf8+j;-*hy wipane 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 ay 9+eivy0gnqedo g;r3+ zg5j1 djustable single loop 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 coil changes f8(ovm2v+ lvtvny 7 c9erom $4.0 \times 10^{-5} \; Wb$ 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 wiken;e moc,/9 :1q;m akj3p yyf0tjfht ;b/*ovre on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coi j/hy /ktey;ck* f;po,aq930je bf:mv ;not1ml. 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 15c ./ao2-lv;i1:smxgk co* (fjr ,pivx turns and an area of $0.40 \; m^{2}$ is placed parallel to a magnetic field of 0.75 T. The coil is flipped so its plane is perpendicular to the magnetic field in 0.050 s. What is the magnitude of the average induced $emf$?

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62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil of 160 turns and are2m4gb93jv/ff) 6dnu fojjc s2vq7f, ga $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span of 60 m flies horizontallyo vz:7 qe7garigxm +) gc.px+: at a location where the downward component of the Earth's a xqxizgvgpe7m og:r+): 7.c+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 il9k7+z blm0g 2.0 m long rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one oflzl9g+bk0mi 7 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 asp( ,2;isc gflrea 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 oo qyg :kfd0t85,8r2zthj;zt+a x8 tzj f 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 rectangular loops oomb mlj -ql:-(afj.bk ul: r1)n 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 uniformlbq rb(luam1k - -).l:jjfo:m 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 wire of -t4on q2rfon8a(f b 93+eqibxarea $0.090 \; m^{2}$ 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 1;nxyf8,xbce3 t 3t9p/vo bzm/2 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is availablec 9om x; zpt3bevb8/xy3 n,/ft. 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 generatoib5hkb0tq1 m )7hu7hv r 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 motor have a resistance of 6.00 W. The motor operates on q7q(n8t wp:.lzctq. b$120 \; V$ 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 mra,v b3 m 0+vmhgg3cf37b put8otor operates on 120 V AC, and when bm bv,ft307 v+ugcp rag38mh3running at full speed it generates a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V power supplyc y( (zt2dnh+t. Thehy (znt(t+2c d operating current is 1.0 A. What is the start-up current?

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74#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V power supplyy9scp+.( paii. The operating current is 1.0 A at full speed. What is acp(p+iys9i. 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. v727ox3nq,yn c:vwk9 8 yiwqc The operatiq: wv,kn37c 8vwy7icony92xq ng 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 a primary voltart7 kh)p8lcgby9(ryet nj/om 5f:r*; +vhk;hge 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 causeyr w:ujhz -f w dl/owh7n+k *5+pxv8)g*xls /gs 14 A to flow in the secondary. How ma/rh + 5uog w*j/llh8*yxwdw-xng)p7 f+ s:vkzny 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 maq1x8sv(kll /jd9ne (gc-bw1 nny turns are necessary in a 110-V primary if the 24-V secondary hasn (w-v9ng l1d8s( lekcb1qx j/ 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 coilff*my5pa2 bb+ and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what is the current in the primap b aff2y*m5b+ry?

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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 transformerm+v uh;*qykrf o)q0d/. Assuming 100% efficiency,/o+y )dh0rfvmkq; uq* how many amps 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 transformer provides 7500 V at 10.0 mA. nr,6,egtloc8i l /1rmh0cqk (4utz1o The primary coil operates on 120 V. What d,rktl rmoc c( l1u4,hg0ni e86oqt1z/oes 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 300 tu d a y+k8bqrmg00d0z1rrns on its secondq+md z01kr bary0d08gary coil. If 120 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 its primary coil and 300 turns on itst/mvtxf/x7 p8s j* h;djs)v9a secondary coil. If 120 V at 2.0s x9v/ad j8 xms;/tt)*hvj f7p 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 transformezyy-;esfg5 i0) e1qx bv+zg/ dr has 100 turns and its secondary has 200 turns. If the input current at the primary is 100 A, - 5 d zbgf)e1sy+0geq/vi;yx zwe 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 txijm *. gm31:bmkb )mbdswy1(ep6 l0turns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltage ol3m1b t(0w m:)6xdmybi1bskp *j .gmef 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 habfo 3mz3jp-o* s 200 turns. If the power input to the primary is 100 W, we can expect the z 3*3f pjo-mbopower 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 avg- 0 unsx0bb)t 120 V. The voltage is usually stepped up to 4500 V by a transfo)bnuvsb 0x0-g rmer and transmitted 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 97cvah w h 4dy9)8bbabowx.7sof current at 120 V. The voltage is usually stepped up to 4500 V 98x yahcwv7ha7 o)bd94bb. swby a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces /o3tl)kr*d y fwvm8f)qb, o(n 60 A of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted th*qfwoonb / y)3r (v)fdk m8,tlrough 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. y onn7*r3+sai4t8 ,cnh vkmb6A generator produces 100 V at 70 A. In order to reduce+r kv mnb3a c8osh,nt6*n4iy7 energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy would be 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 t 34 p u)wklqjfbq6fr60otal 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 j r3b qwp6lu4f )qfk60voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W line a x1s6kh l*d8jcxvy+.mt 1000 V. How much less power would be lost if the power were trdj1 .xml ch6y*xv sk8+ansmitted 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 tof)zf*/f ) b qydv4/ltg6ea5kt be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a6yfvgdbq lf aeztk*)/4/5 )ft transformer if the power loss in transmission is not to exceed 0.010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. How much e oh6+cb cap3 ucnbm/3.nergy is stored in the coil's magnetic fmcp/.haocb 3cu+n6b 3ield?

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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 contaim z,vka:6 7l7bo bppswp (:2cwns a 6.0-W resistor and an 18-H inductor. What is this circuit's timo7,p2:kmb az:p7 lvw6 (psw cbe 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 rmss7+dqqvz w 0h2h6iqr7oi4oy4 voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What is the peak -.zz f/z7f hys x )ealw5ded3rsj 0-b2current?

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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 120-94n7+u ksrx.y5:+ s hd gusxnhV AC outlet. What is the resistance of the lamny7sh+ +rh 5u.9s dn:4uk xxsgp?

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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 po0a5np );h kih vb;el;pwer supply. What is the peak current through ta phhn;; ;belpi0)k5vhe 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 supply. What is knf -xn3 it,t ze(63zvthe power dissipated zivxt,fnn 3z k6e3 -(tin 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 resistoj9p ax a-wdf*(r is $I = 0.80 \sin (240 t)$. What is the rms current?

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102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W rezhau-1qk.n m 7snf :z4sistor 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 resipsx*(rxw)hegb9py c1o7q9k ,ni;x i:stor is $I = 0.80 \sin (240 t)$. How much power on average is dissipated in the resistor?

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104#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the reactance of a 1.0-mH inductja,owaf ecq+-, g.1enor 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 1000 ivnl) z/nhq7 .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 4 xf(a ut*67ttkku ;xb s3f,awa 14.0-mH coil have 14.0 W of inductive reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 157 W:krk t8.vzyr 9j) *bp;mzt+b p of inductive reactance at 1000 Hz?

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108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH inductor when 120inok18: exj +a V AC at a frequency of 20 kHz is applied toxj:ai no8k+1e 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 110-V, 60.0 Hz source hz)p4tfx x 31umm6tq7?

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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 .c, z 2bszg 2v)ui2,oifm8jfx4.7-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 needed to have 50 W of capacitive reactaz 5 3qzepl(nt,- m/2-*pn9ju gzrjoivnce 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 reacfv +k5r8sd /:htj 7fdjtance 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-mzzf oz(*5akp hu;.l6sF capacitor be 100 W? zlas;k(65 u.o*fhpzz

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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 p1we:pdh t9, jat 1000 Hz and 5.0 V?

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115#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the impedance of an ac series z 9 /2ews,jwz03llxix circuit with 12.0 W resistance, 15.0 W inducsxllx9,w w3 zj0 e/2iztive 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, 2bs7mywrvph+dh( 9j 5;0-mH coil, and 1.0-mF capacitor a 95yp7vb ;hjhdw(+mrs re 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 5edmjd . l46 kkchq fp1zz/3+w1.0-mF capacitor a p ez4/z6hw5cd.lmdk1jk3 fq+ re 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*e/ d nzojo lgj;k5:k3-j; gjz inductor, what is the impedance atdj:g*5ge 3 nk;;l-kjzjo /z oj 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 se1tej1h8pd o d/d3wtalcj)/2ie/a5p4uo ezq .ries with a 20-mH inductor, what is the phase angle at 1.hcodwa 1/jpijez4a5/tq1tp8o/32ule e ) dd000 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 ci l,ol bhv0sc8+rcuit with a 20-mH coil and 1.0-mF capacitor for a total impedance of 10lc8 s0lo+vhb,0 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed in sepwnx,v( 0 rckgfrfjyev06(*tf 2t-3u ries with a 100-W resistor and*fj,2-( rxe y pv0k(f6wt3vuf tg0nr c 15-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 0dl9r 43whb edyhoux )+n3ny(at 5000 Hz for a total impedayox(lr )9e n0d 3uy4+w3hnh bdnce of 40000 W?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in series with a 100-kW resistorx-v0q c(.q2do5 9 vrw-asgd7q3ht;dgty) m fj at 1.0-MHz for a total impeoc;7d(fmd -dsy.r3 j )0t tgvqq5 wgx9hv-a2qdance 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 capacitor. What is the 4fkdyda0 qgprw5ul5-1be1 .n impedance at bp. 15wd fe-0un14rdglkq5ay1000 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 uq+q9x* 9/qpsw moh v-capacitor at 1.0 kHz for a total impedance of 45 W?-qq h9oxvq/u w+s m*p9

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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 14*p)xq (ry ggm0-mF capacitor at 1.0 kHz for a phase angl4gm )rx (pyq*ge 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 ns 3;v*zr).,z-r eldauu1 ppcq eeded in series with a 30-W resistor at 1.0 kHz for a total impedanceczppa r)de q-, rvu*1s. ;luz3 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 seriz .g z5 3s2hppgugh/p(es with a 100-mF capacitor at 120 Hz. What is the phase angle?(5uh gzp.p3 gsh2 gz/p

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129#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows at 5.0 V and 1500 Hz if a 100-W resistor, 20-mH coilqloi,5w 4e2g d,f(gs 95fahfv, and 1.0-mF capacitor are connectedga94(s2fd f,w ,lgfei55vh qo 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 ca0.slf(ebi;esdph6kt 4 d ds ,3pacitor, and a 0.350-H i40hsie klpst6 ;f sed(b .3d,dnductor. 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 reacp1bjk7)+bz o naez (s+tance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-k 1j7+)bez+zasb(p n oV, 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 circuiht +j9:i,c-eqkfi m(:wh6 lnb t containing a 50-W resistor, a 10-mF capacici:l(e btqk h6f,-: +mwnjhi9 tor, and a 0.45-H inductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W resistor fo5s g m.+,b7*m iwurmvpr a phase angle of 5mw rmmi7+s,vg*b up. $40^{\circ}$ 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 = 100 0im)uus)3r7z- kj ho/xp reb.0 mF. At what frequency should the circuit be drivhs7j 3 b o0u-rkxe)mu0i)rpz/en 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 sepb6b75k m3iw9ij:zctries circuit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power supply?kp wb zii9jc5tm:76b3

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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 is**q/k am6j jlq $63^{\circ}$. 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. Wf-gdnza/7pt*7 bz:f f:y, ap rhat is the po7fzd*z/f 7fng:a-:,r yatpb pwer 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 foradsee- ,er kgq 3v377n a series RLC circuit containing a 50-W resistor, a 10-me3-gqksdra ne737v ,eF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power supply?

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139#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the resonant frequency of a 1.0-mF capacitor and a 15-mH c 4x +9* zaahlkwr 4ehu:lsfg3j;lb7 2soil in series?jl3 slhk7a4w9fbg*u4lez +xsh; :r a2

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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/xl 2nkst).tr resonant frequency of 10 s2r/)tktl xn. 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 seriesvk 2nv * veyxo(6fo(tnvd0v-;.2o gxx with a 3.7-mH inductor for a resonant frequency of 1000.xtvn- 0v*;o x 6k(do(fno e22gvvvyx Hz?

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142#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor must be placed in series with35hgvd pu400a+*o nk6x) yogohrx7 rp a 30-W resistor and a 40-mH coil if the resonant frequenc05noog 6+ ppxu 7oa gh0*hyvkdx4r)3r y of the circuit is to be 1000 Hz?

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