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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 magnetiwdzz 1yro7 + 0p6qi(8 c ncwaigv2xw;0c 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 inductio ufb8kfh3/ uf.ji8-h snw)fdd+f* c :pn states that the $emf$ induced in a loop of wire is proportional to

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3#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the number of loops of wire in a coi)a zsvnm. l5eiyx;8igcij bh6c/n4uwy-v 6, ,l produces what kind of change on the ind,5wx6ccsyae n.ji iynv li/ ,b;v-)g 4 h8mzu6uced $emf$, assuming all other factors remain constant?

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4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the strength of the magnetic field through a loop of wire produces w -3o ochq2vu.z7x1zl d1-gif ihat kind of change on i3 g- i.zqcxuol2fd7- zv11ohthe induced $emf$, assuming all other factors remain constant?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the diameter of a loop of wire produces what kind of change on the indum2kna q4)f.l 2rv evv/6(ivrucednvrfrv.q/ 2(am6 l 2 vvku4)ie $emf$, 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*1n/ m 82ameyka4wr ;kh) vbdt 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 directivbo0dte i lh*u9va)x :m-ol,u9 ) p)inon of an induced current in a conductor will be that which0:v*9)l)9,nabidlu hmu oto- p) vixe 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 f0(zm8 fa8iirmn+m +dslat on a horizontal table. A bar magnet is held above its center with its north pole pointing down. n+f80 z (dmrim 8i+ams 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. * we6 i cxkegb;v c0bdoi95f:-A bar magnet is held above its center with its north pole pointing down, and released. As it approaches thice6x g-do v:fk 9 5;wb*ibce0e 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 wherc ;k:noscgty: d 33 prtcn257oe the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed g;c :3docco:t 23s pt ynk57nrfrom 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 w( *y -lu( p y9umq wym7:x0,bmllcaf-jhere the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the induced current in this coil as ucpb7yj muf - q9m :ylwy(l0,l(x*m-a 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 magnetic fs2,1v qfjtjfh.c q. 6vield points straight down. The magnetic field disappears suddenly. When viewed from above,f.h.v jqs j1 tqvf6c,2 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 horizontal tablesdzh.ss62;q*n w7 rvpkltm1 ,vq3cr: and carries an ever-increasing current northward. Two co7*;w vz3nrss6qk,sl2p:vrm .cdh1q tils 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 tgtlfquf7 md eooj*3* gd6g7 +.he north pole entering first. As the north pole enters the wire, the indog ut dgl7qo+em.fd7*j 6*g3fuced 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 rot wh c+ e/kwqfmn57j::qe/ .nvyated at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop'nq:wq/k jmvwh/n+ . eyc5f:7e 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 i5p,vm y tgy6w/s rotated at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, y 56,ypwvt/mgwhat 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.k8q /w;hh3ybo
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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 that a,*p xt70 .( ofc5gggv4tqham zn $emf$ 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. yebym 26w 2 * 7k-+pibaw.gmnr 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 direct4z4 aknlm -6u;p9qsksion) is moved northward at conns-s44;l 9aqpkz kum6 stant velocity 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 avs+8* vnai p.jin :(p,rlrjmg 5 v-9qs 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 generatorey .2p8sny3w0tu/geu. vbe ;w 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.4qur rm8he g99qzxo00 The frequency of th 0e 84ogr0muzqr9 xhq9e $emf$ 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 de3e+qd(f;zlvb zu2zs6vice 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 llor (:fsmtq8-x -ca2abe:d i7c c* w,that

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27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the secondary coil contalb.vq*r5fttcaxbp5;b+m- f t0ti *b9ins more loops than the primary coilm blr.q;5tf bft9+bit * *-t0v5xbap c then 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 k4h byj r/)u.tprimary coil contains more loops than the secondary coil then it u)4k /yj.rtbh 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 p heu*n*;z9juxw 6qq6aower 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 ci , k4ydlm6pmlwd+488potxw r.rcuit,

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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 xl,3n)8k*kk : : ppvmehn.qv wseries to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage acro m 8nevw:l.vq,p*xn kkph)3k :ss 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 idealfuc*n: e25eyl aldo2) battery of constant terminal voltage. At the moment contact is made with the battery, the voltag 2conlud 2e*):fe yl5ae 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 induct ,jxsd;0i 2xnhokzi.n3ia:/c ance 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 resista-ek;dxpqu/y j/c6s; j kw;xdhh yg5: :nce 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 serieh3z+q gmhmax7i 4;n-us to a battery. The time constant for the circuit represents the time required fo;m 7nhmuh-xzi43qga +r 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 connectew acvn cv8dqanbw 71l+-z;n* 9d in series to a battery. The battery is suddenly removed f- vn;qlnc8 19dcww z*7bn+ vaarom the circuit. The time constant for of the circuit represents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the same units excepa u6g+n5 lhn zw./xzu1;vh/wqi*dj x;t:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connected to an AC power supply. On th3 t ,v7vvxkm2iis 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 sukkqavu)di 8*e g, :8itpply. In this circuit, the currenak d*v:q)kie8 igt, 8ut

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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 frh86dy7 ;lxfv-+cnkibequency is triplv; + dihf-lc8b6kxn y7ed?

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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 ri02 ji0ol aux0-+wgqdoubled, the inductive r-0olrjx2w q gu00i ai+eactance 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 across an inductor approaches zenso1rncp45/ . x.m qkiro, the inductive rk.5opms. 41/n qcxrineactance 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 circuit, the 2/bdk- ,)m a befdn8s.fz 0h9bi aiu-zcurre)i f8k.-9m bu-zb,a/ehs0 d2bdnzfiant

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance0zjf o+ armt3-lz69eh in an ac circuit changes by what factor when the frequency is tri+0 zmf-e69 3jzatohlr pled?

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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 lx4 l*3 ymp1zya capacitor approaches zero, the capacitive reactance of l*mypz1 y 4xl3that 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 (fvmp0dq v 6-c7zzew- the inductor and capacitor in a RLC series cvpz6(d-zw 7vqe f0 m-circuit?

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47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The power factor of an RLC circuit is definedhm6 7soo38a *fqc*wjy 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 rtrjfr ;( pls)t-/jdvvr+54iimpedance of the circuit increases if R increases. When is this statement truejfrr( pst-v5d ri ;v)/+4jr lt?

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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 if6b48 n t6o-,2shr usqki; lbsncreases 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. ;za8pzd;z 5)(jjtisoyx7 k+u The impedance of the circuit increases if $X_C$ increases. When is this statement true?

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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the inductance and the capacitance both double in an LRC series circuit, the 5:5-dhxmk2fu - abdbiea)k 6 vresonant frequency of that circuit ua6 -eb: 5 -bv5)2ahdxkdfkmi 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 AC applied volt h8mcxxlu:, 1wbm q(0cage. 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 cie;a5ih(wm2owegm a aw * (3 e9mas)g(/openo7 rcuit 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 , 3604(kyub nfcwfvxhc4i duo;v6d 2ia uniform magnetic field of 0.20 T. Find the magnetic flux through thew03f6(xhiyoudf v4d 2 ,n6cb k; iv4uc 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 magnet2 wm j2/hd)tlhm opp63,;lafric field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are perpendicul26 r /ld ofm)j2t3hp;hlmw,pa ar.

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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 radi r/52t5l:cdkg,wygkj+vit h0 us 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the gd+v/,5 icjtlgt5kwrh :k2y0plane 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 reduon+sd pp4ks9*k0 g 5rgced 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 from lou +-afme x84$4.0 \times 10^{-5} \; Wb$ 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 witnp 2+oknxg1 nsa,i,jlusk9n azs 26+5 h 200 turns of wire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the average value on6+psa 2 ,n9jkluznsiax,n5g1 o2+skf 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 tur(0 .d gzr/wixd:4t4s:tayvn: hae ls;ns 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 ah7as mc;8qrwg g7 r ,n5f tkktz2u7+)vrea $0.20 \; m^{2}$ 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 hm0 sv3x ;yzy*dorizontally at a location where the downward component of the Earth's magnetic fie dy03symz v*x;ld 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 zw )8rl)rjo86ij9 k uxlong rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while i k9u)ijl8w8zj)rrx o 6n 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 a+yxm4 -ntgp) mttsnio.im sbi,.mz60d8t,* cnd a cross-sectional area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of a5vq xp+ l-b3g;p lbn: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 1i/vd/jz w;hqs1 vmrwnt.b-/ 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 perpendicular to the axis of rotation, wh- qv jnw1;z /t d/sib1/vhrm.wat 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 10091 guqx)+,fdpn/b a da 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 construct a simple AC gen7fiqe.y t ru2tc8do 83erator with an output of 12 V maximum whee7 83d .8cttri2qf uoyn rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of the rotating coil is $100 \; cm^{2}$, how many turns are needed?

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70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are designing a generator with a maximud/ :wyd;y 1xx):rqj ,5ck lzssm $emf$ 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. T s *u5 3 ptj*(szz)er1nn) khu*d8lhgfhe 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 +hs;-qnb qsuo 8kh0u4 operates on 120 V AC, and when rnq+; shb8h- uko4usq0 unning 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 t + 2.vpfz8qeey5kuse+ o a 24-V power supply. The operatingfu+ezk.vyeqe s+p852 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 6d j4mkuvt6u5.f/ m6ox .0 W is connected to a 24-V power supply. The operating currxm56 4 f kdotuvm./6juent 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 is connecte 3roo d 8v69,kpdvs;tbd to a 24-V power supply. The opera6dsprkb 8 vvto3 ,9od;ting 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 transforo,3mudfyt42 q- fdfb/mer is needed to reduce a primary voltage of $120 \; V$ AC to $6.0 \; V$ AC. What turns ratio is required?

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77#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  2.0 A in the 100-turn pribdt4t2s / vx.vv a5iqd2m;3wxmary of a transformer causes 14 A to flow in the secondary. How many turns are in the secondav/ wa2i5t3dmt xb qvd2x .s4;vry?

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78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, how many turns are necessary in a 110-V mg9jyw ha8 )3rprimary if the 24-V secondary hash y98ra3 jgmw) 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(p cf27bjv9 qb coil and a 2000-turn secondary coil. If the curreqfj 9bp72v cb(nt 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 pr5nr3ylr;w4: tzt ep6** teqzk7ge7ls imary of a transformer. Assuming 100% efficiency, how many amps at 24 V can flow in the secondary7ynep;etk wz7r34 5 l 6lt*z:rt q*seg?

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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 apkue 64(wqie,;5 , *npgzoed ut 10.0 mA. The primary coil operates on 120 V. What , uoedie;p46 k*zg q5wue, (npdoes 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 cd k-q/- b7xj wf/fyi:soil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what v/: 7jxdy f-i-wq fk/bsoltage 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 3tww4(bq3 w7; oyemu xa8,uhn/ 00 turns on its secondary coil. If 120 V at 2.0 A is ap;/ x3q (w owetwm,u7h4anbuy8plied 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 tran 7jn; -ox7b 9syeikl 4kf6cg.fsformer has 100 turns and its secondary has 200 turns. If the input current at thx6f syk bkog7f7nie;jc9l 4- .e primary is 100 A, we can expect the output current at the secondary to be

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has 200 turns. I(lhhsca 6t4 o;f the input voltage to the prilt64c;a(oh hs mary 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 turns. Ibq57et8xi d( kf the power input to the primary is 100 Wx k7te5q (8idb, 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 of current at 120 V. The wt5ja0zcmj t0qvv j6 i(y x(w /t)(m5xvoltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the number ojx6(vyw/j0 mj vt (0a5m5ixt(cz)tw qf turns in the secondary if the primary has 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is u u;0ns4 rxmtam)hp/x)sually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lostm)h );pmn4t x0a/ uxrs 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 07 ;lrtwgis s6voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total ri l7gtw0s6rs;esistance 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 q(+6ilp538s n(shu sn + dlrxtresistance 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 8 sl s(6xpnr3ld+i( sqht5n +u100:1. 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 lin rsz33lfu4;vne 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 ratiufsn lvz33 ;4ro 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 at 1000 V. How hv b,*owl3d 4 q4354faild*wz llyl7jmuch less power would be lw *3ozid d3y 4 l4wj,l5 47hbvfa*lqllost if the power were transmitted at 3000 V instead of at 1000 V?

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93#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The output of a generator is 440 V at 20/vzqr e22xe6o y4 .zadf6 e4kp A. It is to be transmitted on a line with resistance of 0.60 W ek2/operde zx6 424qaf z.v6y. To what voltage must the generator output be stepped up with a transformer if the power loss in transmission is not to exceed 0.010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. Howbi/ b 4b1*b:3a w+fc ekgs)znw much energy is stored in the coil's magnetic field?41)swi wb+kbb: /bf 3g c*azen

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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 contai6;sm lej,b4 cfns a 6.0-W resistor and an 18-H inductor. What is this circu 6 ;ecsj,4blfmit'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 theg/oz7 f-,kfp h, .pvbr 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 120-V AC os*udwen g5m 78hv/gn( g7j)uoutlet. 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 intoxf )dufc4 r/q. a 120-V AC outlet. What is the resistance of the lamp?c/4f.qdx )fur

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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 -)qziw + +qfijto a 120-V ac power supply. What is the peak current through the resistor?-fw)qiqz+j + i

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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 suppla4v)tuoey3:se6-xr o 7:wot p y. What is the power dissipated in the reso7oe s:3-xvet64ro uya)t:wpistor?

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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 sisvbe0s3v,o hvsp748e,dq9 50-W resistor is $I = 0.80 \sin (240 t)$. What is the rms current?

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102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resis-7jy +xdw2 g la3lgy *wq bwehxuji4q()w;.r0tor 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 5 .hey:vde1d j+ipw( f;jmeb3 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 reactanceqxli z4tgy: yat7bm h r /x,08d(r(3ie 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 1000 Hzl s+st9we w-9. 9fowogenep7;?

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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 W9cy q 4r0 wy-mnyf+4si 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 necessa flj8lf.c0 hv. wvm 0/hit*ror14lr3p v1 du;wry for 157 W of inductive reactance at 1000 Hz?

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108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH inductor when 120 V AC at a rung: we6 9+ccfrequency of 20 kHz is applied t 9+:ugwncecr6 o 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.zb.v *cubr* id*e 3x/u50-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 10 kHz s s-dpme)mz qd/u4:0y?

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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 eawrc-i 59 reck- wqq 43x,j9kto 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 1t e*ozuc 8stca+*jvksk;wa 0i5wg7 7a 10-mF capacitor 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 -u/5 vd y3h ro(lyi;hlpryq11be 100 W?p( iduoylyv53h-;/ r ql11y rh

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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 104 gk .**gnifsb00 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 seriesu,2zrj dygven8f5,j 0 circuit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W jz82g,5fjdn y0 eur,v 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 *(0m/m/wn2vygzbb;)f aeuztc g on) 3Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capgu zb)b v /te 32c*nom0;yfmnawg)z(/acitor 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 1500 Hz if a 100-W resist1pp4la83 9:orab +o qt- hwvncor, 20-mH coil, and 1.0-mF caponq-t3ao1p:p 8+ 9h lcbv4awracitor are connected in series?

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118#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-mHws,xo rp-nbw(w ,g9a2 inductor, what is the impexwpa-n9ob,w(g,s 2 w rdance at 1000 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is con)p5cy9t :j2j vw1 h.(ngbl iqknected in series with a 20-mH inductor, what is the phase angle at 1000 Hz?g 2tv :qy)cp1nh5 k(9i jwb.lj

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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 tet54 xm4m,9oik h.lv series circuit with a 20-mH coil and 1.0-mF capaci 9vo. kx5m,t4 lmi4ethtor 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 followin3n4ale tu 04gag capacitances is needed in series with a 100-W resistor and 15-mH coil to get a totaa4aln e 4g30utl 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-+*dgi45 clm e)iypjick h e-p818gle:mH inductor at 5000 Hz for a total impedance of 40000 Wp4cepj1+e)*ikcg-8 gyi e5hil:m8ld ?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in series with a 100-kW resistor at 1.0-MHz for a jqfd/8 cola50total impedancjd/f 5qa08lo ce 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- gsr4) g(ak5emku h.ryw()9kp- wr 8daz(z,xbmF capacitor. What is the impedance at 1000 Hz(-k5ze. (rw)gu pk9(ga,yhazkr4xdbw8rs) m ?

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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-k(w jgt+8 o7fdmF capacitor at 1.0 kHz for a total impedanc7+gd( jo 8ftwke 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 we ,nyt eb if2ml)2q9t.v 7ewj3jzy: )9yx.klgith a 10-mF capacitor at 1.0 kHz for a phase anglefy9) e:e3ey7q.nw2,g l9v2mkzblyijjt) x.t 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 newwfgt l/(b,iz(19 ke9d ts6 )ns gxp(veded in series with a 30-W resistor at 1.0 kHz for a total impedancesf1(psgwn t/v, (kbld tez)w ( 96xig9 of 45 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 1x/x 88qb / xc )j;d,.x-jwwbwocznv d:20 Hz. What is the phasxqd wj ,-n . j;b: 8/xvw)dcx8xbwo/zce 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 100fv 5xk4-fvc 0i-W resistor, 20-mH coil, and 1.0-mF capacitor are connected ink xfi50- vfv4c 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 10:uwi fx /k 7dp3)vir -pf1mqd5n; (naf0-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power supply. What is the rms5 i p-1f;:w3fuqdrx/n 7pmd(kf)avin 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)3zohp vtx:l9j21fbt h0 +fm i, a capacitor of capacitive reactance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz powfbj f12t3i+)h v: lxzo 9tmh0per 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 hei0s)fld6a k f4+q3e RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power suppfael6de 0 4) +fhki3sqly?

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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 resuul4yz3fuoak n1 7).histor for a phase angle o7y uk.1 hlf 4zau3nu)of $40^{\circ}$ 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 haxw .(zl3 +v.ntly6nezs R = 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power .zwll ny.+6v 3 ex(znttransferred 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 wi q hotrsu+irk1h557.wth 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactancers5tkhu7 wo1i.5r+h q, when the circuit is connected to a 120-V power supply?

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136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an AC circuit i :ta6pq5ui/i wx + s;8a zy2:mbeuif*bs $63^{\circ}$. 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. Whatxe 8,m *utkd/u6cm ol. is o kt 8cmuel 6/u.*dm,xthe power factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series RLC circuit contagcq5wiul88ly kv :u42p m)a+sining a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductoaumv28q + g48p) yu5l: cisklwr, 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 fv;q dr fwbiy:o7eb jns3lg,k2n 6j);yn6gj 2)requency of a 1.0-mF capacitor and a 15-mH coil in series?wvf )enosj3n jbg 6y), i7bq2 d6:ryjl2;n ;gk

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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 ixf(m6ii jz;g 8n series with a 4.7-mF capacitor for a resonant frequen; 68 gxzi(jifmcy 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 i6qzxq + 09pzc9fdzy4cjed l9 ;nductor for a resonant frequenc+cdpz9qzfel; 96 dj 0z4y9x qcy 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 placed in series wit 73 mzbn3z p7i-p sc4fzjn2yk(h a 30-W resistor and a 40-mH coil if the reso-2iz7n 7 sbkyfj4m( 3zpzpc3 nnant frequency of the circuit is to be 1000 Hz?

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