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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 magnetic fgy dg(jl: unanmgc89 9h:7 kad5hr4,hlux 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 thatyjfz s9;vqd-1y5aidn0p.k z 5wm, 5bs 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 p 1-0wv0ma9 tt+kdlew qroduces what kind of change on the ik0 t1twe0d vma-+q wl9nduced $emf$, 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 thexz acszgb 1emn):0hi/;*naq: magnetic field through a loop of wire produces what kind of changen;hiezaams g z x)bn/:c1:*q0 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 wire produces what kind of umgj x6 sj8)o9change on the inducemjg86o )sux9 jd $emf$, 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 fromy6ai 1*r9w amv+t6qr c a magnetic field an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's ll ;+wucd4v7q0u p7zyrd ;cn*l:m,xj naw, the direction of an induced current in a conductor will bezv q7,*+dw7;p0m;lj duycrnuc :l 4xn that which tends to produce which of the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table.lc opt.flj 8kz139,qinadf* 5,6icmg A bar magnet is held above its center with its north pole pointing down. The stationf8* omkzd.c56cig, t39 i,q plj1alf nary 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 horizo : d6tcjoii5*mntal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil,dcmi5jio t: *6 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 tab; 2ivk,-l- e0potfb .*g v-qk f.u eeh(jbvx:tle top in 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 th-k,vbp.tg-; e 0v xvjuqtlh *kof fbee(-:i 2.is coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top in a region where the magnetic fieqp:1 zunx a3;ru g 69f7hnzz(ud88jjv ld vector points straight up. The magnetic field suddenly grow xufur;j9(:8 ngz qpu hj d63anz7zv81s 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 tardv0vy- **ucuble top in a region where the magnetic field points straight down. The magnetic field disrv* uuv0dy c*-appears 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 ;+iv joyanmav;ld3nxk9.9 /thorizontal table and carries an ever-increasing current northward. Two coils of wire lie flat xki;lvt3 / j+av.dnyom9n a;9on 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 nortyc-x ( l b8hkje)g1b65 gimxh2h pole entering first. As the north pole enters the wire, the induced curre x 5(ckhbm)ji26l-e 1yhgxg b8nt 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 adys zscrh i 7y;(r+2v3t constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's d2z hrsv ;sc3yiy 7r(+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 rotat mk)yemck a xig.0s)i7 ey+ z0s4gz8w.ed at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotation if0m )zx8szikg sc0emw.+g yiy a7 4.)ke 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.ftt,imlt*nc/b(6c f/ qv7uc5
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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 thatxb/.o .dz8 t1zt + 6jbnjxnvp4 an $emf$ can be induced in a loop of wire.
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20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A wire moves across a magnetic field. The 1/udec8ey/4 q cyr fdt)5x 4fi$emf$ 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 z,yws3 v zf:.eqqsx ,bm3hu 81east-west direction) is moved northward at constant velocity through a magnetic field that points straightq eyqzs3hu,8vs mx:1w fz,b3 . 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 constant angue53 gr*g.ok5cat4)l /aig zf ular 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 transfatt -ncpe j:*2f qs8x3orms

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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. T s ;zv+i-svbt,hm3xq2he frequency of theh32st zbv +x, ms;vqi- $emf$ 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 u(vkpt6jwg8t2 :iqd,g/m s2cr sed 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 devi7(dwyr,wluif rp( -c 8ce 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 contains more loops than thej6a .4(bfv7dm:piuny primary coil then it is 6y:(jdmfpvi7na.bu 4a

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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 pris3k(jg zjr4c 1mary coil contains more loops than the secondary coiljzr jsg143k(c 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 inputj0v v 6+rz.m4pjaap0 n

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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 resonantoa1jkq s,2 i49mn(hy i +gb1(ucrn0gt circuit,

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to an ideal batterkdgd 2wpu,-b.h g j9, c:8(b(zv sseqfy of constant terminal voltage. At kzd,v:9qf,. uwd h-s bje(gb2(p c sg8the moment 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 connected in series to an ideal battery m)z)6 klrzs/i of constant terminal voltage. At the moment contact is made with the batzlzim)6 /rs )ktery, 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 indu*u *vtrrs 9xlm- ,*poyctance 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 inf -7qcmu vwgva)(xv92 ductance 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 batteryps ;p4nf2 3qg+ywyrg +. The time constant for the circuit represents the time required for g y+fqn;g pr+yws24p3the 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 r4jg +vr3o or*to a battery. The battery is suddenly removed from the circuit. The time constant for of ror43+ j gv*orthe 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 e uoq fj+6802wk ucl)eyxcept:

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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.8rcn *vx:kxl7 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 cirzcr*:k a;xoh f9p7g h5ng/i 2vcuit, the current*f:;h goxhci/ g275arkp znv9

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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 changfph(lo+z jo0+ es by what factor when the frequency i 0p+j(l ohfoz+s tripled?

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41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the frequency of 5.0o.(wg4jatkkl1 f9jnsl ypthe AC voltage across an inductor is doubled, the inductive reactance of that i90gk5fot jy p.sw4nljak. l 1(nductor

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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 app:; l9scw(bnx. egjf(j roaches zero, the inductive reactan .(c;:ejbfxnwj(9l s gce 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 no-pm (8tmyp9wib 1 r8x-ur p+tzkw 9*supply. In this circuit, the curremn- +89 ptt-z*xwpoby 8wr1 k9mpuri (nt

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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(ek /wgq px(3nk76okl the frequency is tripleg kkw 7( xqep3ol(nk/6d?

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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 voltagek +4rpkm,qiv (4j5v rvxhc e67 across a capacitor approaches zero, the capacir4jqr,h5vm(v v +i7x k4k e6pctive 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 bef(u5,cf3,ynrhngog 1 tween the voltages of the inductor and capacitor in a RLC 1 gnu,r3y 5f cghnof,(series circuit?

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47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The power factor of an RLC circuit is defined oj g; m(q:pan,as $\cos M = R/Z$, but the phase angle can also be calculated from .

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48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the circuit increases if R w+1r i gujn 0 ltyyw+-k 3psl;b4hl1y9increases. When is ts-3lt;++p9y whl gkr14 ljyu ynwi 1b0his 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 circu -hvlkz jbqj y*n1570uit 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 impedacqt uf177-7 :enax whince 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 doublo 9oh)rkp1o+wh ol5ffb,hb :+e in an LRC series circuit, the ref+,ob)bopo591 + hwrfhok :hlsonant frequency of that circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is drivv vu47(u u49s tw1lfmben 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 circuit occurs whhh,tzb7rd 9 ;ai. i7a s6umqg-en

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54#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A flux of $4.0 \times 10^{-5} \; Wb$ is maintained through a coil for 0.50 s. What $emf$ is induced in this coil by this flux?

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform 57o3a2y1 dkt/gc tt blmagnetic field of 0.20 T. Find the magnetic flux through the loop when the plane ofac/btd71ttok2 y 3 lg5 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 rotg 1dqtdy2f0n,cw;b0 c ating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magne ;c g0fwbdtyd 21n,cq0tic field vector are perpendicular.

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57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniforwivij4pvk8unk 2 4;t ,m magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic u8k vkji4 n,;vw2 ipt4field 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 reduced frowhnh e52l;h39ri cx*t 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 coil changes fv/qjv0bsm/0r rom $4.0 \times 10^{-5} \; Wb$ 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 s1r7o7,r7rqr,jk y:c smj4 x naabta;1 quare frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly ftj;7r41y,jkc r,7axq :1a srmba7orn rom 0.50 T to 0 in 8.0 s, find the average value of the induced $emf$.

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61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A square coil of wire with 15 turns and8z, psnlav o,, 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 areah8c 56cpr aulwzfcj8;4q1l + oen9-tp $0.20 \; m^{2}$ 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 horizontally at a locatiouxw(gy -3n iq35.rmc aa*vmmr4 o *g4cn where the downward component of the Earth's magnetic fielwganro g3*( ya.c3i45mmr4vc-u *m xqd 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 qk2g1ek b0-hd that is 2.0 m long rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of-b0dkhe q1g k2 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 lz; alf w46d;z0j ;+gyyoyq 7proops and 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 100 tuz72faapb7 x0 adxua 5.rns 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 looer5jr; sxbjure90f pgca ; 0/(ps 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, whichbeu0 jcg/f950 ; a;seprjr(xr 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 o cv:i qgvx/s0 )gk/-kff area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced current.

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that you wish to construct a simple AC generator with an output of 2 u9*b,tsydlf 12 V maximum when rotated at ldyt f2u9* ,sb60 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 )yq)wkc qu5 f.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. 89ksk x+mna4t:g-(nfq6ccfs8jrax ( 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 lttf +b:h)n8j6o1av awqeq; (a.dk y 3have a resistance of 6.00 W. The motor operates on 120 V AC, and when runkw1nvq+f:oh (yj el dt.at8 a36;ba )qning 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 roiom5u/qml/e(e x 76wa )jtb2fh ,d)yesistance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A. What is the start-up curre 7aq e/hmo25tmu6(wbdlx )jf,yo) /ie nt?

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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 res3mp ns kj+f t6;w)lm31ccic k*istance 6.0 W is connected to a 24-V power supply. The oper6p3lwfski1t+m;m c* k3jn )c cating 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 is connected to a 24-V pwtp9/i)dat0m ower supply. The operating current is 1.0 A at full speed. What is )dmi0w9 t/patthe 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 vo:fgj5igx.g;ju p-e u1ozb1 :o ltage of $120 \; V$ AC to $6.0 \; V$ AC. What turns ratio is required?

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77#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  2.0 A in the 100-turn primary of a transformer causes 14 k(h6a,n9d n up(img.h A to flow in the secondary. Hn.,(g9dhn pk (ima6huow many turns are in the secondary?

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78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, how many turns are necessapp7duk wz- z c6g/83uzry in a 110-V primary if the 24-V secondary ha8dcz -u36zz/kp 7 pwugs 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 v/ sjc7- hhqj pijn:.9a 500-turn primary coil and a 2000-turn secondary coil. If :vh9 .j7jhcjpsq-/ in the current 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 transformerl(/ lq*a ptf(9f tp+km9bh7ll . Assuming 100% efficiency, how many amps at 24 V can flow in the seconphtfl*m9+ 79 lfk(blp q/la(tdary?

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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 x3-v yioy 1n2(c 9tbxgbl-(u8 p qy9ptV at 10.0 mA. The primary coil operates on 120 V. What does the primary draw8y l-(gpx-y(ct9buq 3tnxy9 1opvbi2?

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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 turnsf 0)e)wn piki t2)+ j;ohsj3hc on its second)npws32 o ji0tkfjihh +;e)) cary 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 tuvf85h2 gflky 5rns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what f5y8vhgl 52k fcurrent 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 se2eej0h j*;t2 qlhbdfg c+(t 4dcondary has 200 turns. If the input current at the primaryhbqdt2c t jd(02l*gf;e +4 ejh 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 tranyr8b-4 m9(+( gk / ej8dkcdg lng(hmnssformer has 100 turns and its secondary has 200 turns. If the input voltage8+(j-8/9e4 l bkms( ygkng (gcrdmhdn to the primary is 100 V, we can expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer hasbjfl5q3 l99rt,:dlg/ rt gm 0t 100 turns and its secondary has 200 turns. If the power input to the primary is 100 W, we can expect the power output of the secondary tol/lgmdf 99 jb rtg03lqrt:t ,5 be (neglecting frictional losses)

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87#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is3ejz1n x:mfh . z3chsax 4(l +p-k z..ldxre1f usually stepped up to 4500 V byzm eh(cz33axx-r1z +4 : l kd...jfn1xhplfes a transformer 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 of current at 120 V. The voltage is usually s+k0;wj 3vnip:4fv vieco( *e30qkku stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the pfc vu;s+jee 3k0* qn3 pv(iko0k:vwi 4ercentage 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 usua 3jfmlnv 93u7 jhez8+blly stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lost in the transmission line if the +v h87z3mefbjj3 l9nuvoltage 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 hpml6t+ k*h6t0.60 W. A generator produces 100 V at 70 A. In order *mhp tkt h6+6lto reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy 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 of670 xo li0fgs, 0waf-)pmzxff 0.60 W. A generaf,gpi0f0 l -f)zofax60 mx sw7tor produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost 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 much ng+. lr gq/2rc*lf30 4zg pkthless power would be lost if the power were tr*0ch2t r4gf l3kg.lzpnr / qg+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 to be transmitl..yai n5 csh7 ml;ve)ted on a line with resistance of 0.60 W. To mlc7 yia;.nvs .hl5e)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. How much enerxt t0t )lyb,nzah )j2rfdw0x 9t +l1v;gy is stored in the coil'svltxx0)tfzwtt 2,r+ldna19y 0b j ;)h magnetic field?

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95#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A simple RL circuit contains a 6.0-W resistor and)n9)( xx my2hsdalq g6 an 18-H inductor. What is this sx))qm g(hd9l6 2xayn circuit'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 n1zkj9*kjku qre*s . (puoo-4an AC circuit where the rms voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed uxnw02 (rp1odlgpdwm 4r 698jsb: go- into a 120-V AC outlet. What is the peak current?

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98#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a umer+ 7apvb)8:/ c -:thra iy4vyk.ah120-V AC outlet. What is the resistance of the lampyk8)yvbtr./ih4u:7 a :-eac m vr+ hap?

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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-vtdli mk7e y.:35ye 5aV ac power supply. What is the peak current through thekileva e5t.3y d ym:57 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. Wha/gl(m i0 ku or,45zr.00u rgn+ guwj+5xlwtvjt is the power dissip g0 w jn,x0v 5kir (0+4gujuo5grlwrlz.m+/utated in the resistor?

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101#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resu15 aer 7ig.ctfil64k istor 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 yfh+gu,8 s f,br n7je r3pf.z* gj*(hqresistor 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 ,yl +h,pmz*zta 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 reactance of a 1.0-mH inductofjjgu ;.rnq /35 oojm;r 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-msi n5co7v x 4t+b+dpy)ej 3a ypj+u5+pH coil at 1000 Hz?

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106#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will oyvty* ,wg:9 zcsj9 o;a 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 of c26eu+co q drvj:8odbua n;q )9dodl(3. kxi6 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 12hf48 rn1hy1dg;muf/s0 V AC at a frequency of 20 kHz is applied to it?h4s1 ;/dr8 1 fufmhygn

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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 sourcitz.ke mef +sf(/:.3 fah x8wse?

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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 zcizq; kp-g srp,-.5axtzw79 of 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 needed to have 50 W of capacitive reactance at 10 him)/3r cca/ wkHz?

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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 reacelt 9/*3 ewkwatance 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 wiol b :x(r- gd7ihr,j5bll the capacitive reactance of a 0.010-mF capacitor be 100 W?-(7lb , g jr:hr5bodxi

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114#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 0.0010-mF capacitor at 1000 Hz and mlpk (u*s,z)u5.0 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 circu 0w: 8qna4vggp-3lpc mit with 12.0 W resistance, 15.0 W inductive rlc 3m q-0wpvn4a8g g:peactance, 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, 2jnjxb ybdvrzwf:lf3,5+s2a7 dg j1 0 +0-mH coil, and 1.0-mF capacitor are connected in j :0vyb13jzxfn, 2 5sdrfwla7+gj +dbseries?

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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 anglei70nhvi7+kr d4j6 ugq at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in sehu7r4i+7jkd q 0gin6vries?

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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 connectedeo uyo9*,)+uwv z9o mu in series with a 20-mH inductor, what is the impedance at yw zuu9m+ ve*ou,o9 )o1000 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 induct.bbtnoo0 8p s/or, what is the phase angle atbnt0s8 p b/.oo 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 circuit with a 20-mH coil n14pzg vu0c+m and 1.0-mF capacitor for ac z+1vm4p ug0n total impedance of 100 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed in series with1tmo4 vmp4+8 ie)bnie a 100-W resistor and 15-mH coil to +m4p ib) iemt 4e1ov8nget a total impedance of 110 W at 2000 Hz?

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122#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance must be put in series with a 450-mH inductor at 5000 Hz for 6zpu5 a7o s0m9 1vvp8:oip zsj/5mmcua total impedance izsvmm/j 10ppu7o85 :mc au 6vpz9o5s 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 resistor at 1.0-awd2m;+lv4m0ol u 3w 2n fjg19tl-qp iMHz for a total impedancewdlmwi23- 0tlonv4gla f2u1m p q+;9j 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 capariky 55(-ctsjcitor. What is the impedanc 5sc jrkti(5y-e at 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 ser+iikc6noil2 2ies with a 10-mF capacitor at 1.0 kHz for a total impedance of 45 i 2+6l cikn2oiW?

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126#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-mF capacitor at 1.a3yd1flp8d 3 )ks 3cbp0 kHz for a phase a183fad s3p) ykl cdpb3ngle of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1.0 kHz for a tj mf;5t)f9lsy,l /zrs,ls fg (otal impedance tyz ll,sf/f9 j(mg l;,)rf5ssof 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 10fgwcwi7.1 l +c0-mF capacitor at 120 Hz. What is the phalw cf7wc+i.g1 se 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 resistor, 20-mu jtkx/ : zpg/g8oca)0H coil, and 1.0-mF capacitor are connected in sericup / ) koj0t/xazg:g8es?

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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 consisxyz:9+wa : dybts of a 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductw 9x::zydbay+or. 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 capaci yr/4,ryy8icdtive reactance 30 W, and an inductor of inductive reactance 30 W are connected in seriesr8dyric y4,y / 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 containing a 50-W resc oz4awo *-i)cistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hw *oo ci4)zca-z 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 for a phase;kkml x+:o 6 twk3i4bu angle oo + uxt6 4b:ikl;wk3mkf $40^{\circ}$ 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 h m/ /+7ybq7lsf1 sz:+dvyxv, l+hmwvf as R = 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order7zxm yq+fysl/+1mv/vlfw:, +h d sbv7 to have maximum power transferred from the driving source?

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135#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power output in an ac series circuit w2 pmp2zje,uq5;oq7c jf. gm;with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive r7;m; jgem5fcqpwp o q,2j.2 zueactance, 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 cuz2 vi b4a*0u) yw8p9ucfddev4m7 y*pircuit 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 impeda j tt*voflz-wkxd. 33)nce of 60 W and a resistance of 30 W. What is the power factorxw .tf-k)3t dz3j*l vo?

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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 yfi8 kf,v..v 65 rvofnfor a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, wh yfo6i . vn5f,v8kvfr.en 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 ofxcdx4xp+zq 181 x.ccq a 1.0-mF capacitor and a 15-mH coil in series?p.+x x11xdcqc 4 zqc8x

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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 capok -(oki1vzs 1acitor for a resonant frequency o z-iov1k(1skof 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 neediz q1gx8,e 7vfed in series with a 3.7-mH inductor for a resonant frequi8 1xzqe7f ,gvency 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 with a 30-W resistor ann* exqtwp1z v;w (ccu3,ps-s9d a 40-mH coil if the resonant frequency of the circui,uzcp w- v3sp9(s; *1tc exnwqt is to be 1000 Hz?

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