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习题练习:Physics Unit21: Electromagnetic Induction & Faraday's Law



 作者: physics   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 flux eeq3u/ o.4dwl5.zt niu xcept

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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 induh0auwqq kez m6gu3j t(7()wc91 h ufc.ction 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 coil produces hxas)evd3 m4el-o-:ewhat kind of change on the induced3)-sx e4e-m eoa lvh:d $emf$, 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 througcq9o 5 c2:4a,lla cfhdfu:( qrh a loop of wire produces what kind qc (25:frul9,l ha :doca4fqcof change 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 ws:q zmj(juys5 b+ lqqx4 6q(8lire produces what kind of change on the inducj q 6m(5zql(lsqb y8x:q+ uj4sed $emf$, 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 fi,+upfsy/0w-k vyll (z eld 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 inducykw7/di9l b4f4ul) v ted current in a conductor will be that which tends to lwk79)vftdbyul/44i produce which of the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A bar hc/g hq6w:u) vmagnet is held above its center with)q 6/vh: hgcuw its north pole pointing down. The stationary magnet induces (when viewed from above)

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A bar magnet is held abovelyf/vaqs+:12ru4 zh hzw4b( xzvqd45 its center with its north pole pointing down, and released. As it approaches the coil, the fahqu1w xs45vlh(by 4 2 zzf+vaqd/z 4:rlling 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 4e.;6ec qzjtq region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field fade.e6zcqjq t4 e;s?

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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 tabl9ge jvkth0(7x)fr xn-e top in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, -j)v9xr (knf7ht0exg 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 regi hlgdjm 9/9gkx4usxu29) qm5d on where the magnetic field points straight down. The mam/9 q)xx9hdlu5gm4 9su dj 2kggnetic 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(rb 7q*wf6yum 2fde ut.(2aobl table and carries an ever-increasing current northward. Two c r(b u6mb(o .q*yu2a ted2f7fwoils 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 noi 7n.l lzvf,o(rth pole entering first. As the north pole enters the wire, fn.o(z7 l,ivlthe 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 angul(*paz b5 a7txaar speed about an axis whose direction can be varied. In a region where a uniform magnetic field poina(atpz5 *ax b7ts straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be zero?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constajwu62w +ud7qtfigcs9 3p(, dgnt 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 qcwd us +9gi dw6,732gfj(uptof 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.8(x7w oksjr4ng:*hlgv4nz, bcf0w u :
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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)rwb3mw(u*ukhbk1va, n (e e*n $emf$ 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 fieldkzbfy.a1v:f hsgm*huvgmz+d- iv805u8 0el -. 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 di 7ahe5,e1gq0 rom9x corection) is moved northward at constant velocity through cho90ar7g1mo qexe,5a 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 con0 4wq*t5ms3j; zzjnvnrc, ,pvstant 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 tran3 kgy4mi pygou *f z;-n:-.pohsforms

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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 secondhq-dbfu5/ el.62c ve- /o(*vt x zdmzh. The frequency of the d.dvz-x/5e* uc/ e(hmohblt2-qfv z6 $emf$ 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 deveqbz(a:2 nl z:ice 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 thaa bw./ql ,x:iht

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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 secondtf 53/eysq 3beary coil contains more loops than the primary coil t3ebf y5ste q/3hen 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 3u8p3)bxc1n3w q o rwfcontains more loops than the secondary coil then it is 3cf8xu 1w wqrop3b3)na

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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 inpu2jb/l+wc kp)rj+6:ol2qi uvg t

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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 circh)ovzw 7ad .n4gyh9.3jq jy6iuit,

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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*xac:frk ; vbf*if q4fd)9ta . battery of constant terminal voltage. At the momeak9rvfb*xq :ff4a) fi .d;*ct nt 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 ind/7u, (lhxjrxnuctor are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the volxxr,h/ (u nlj7tage 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 re3s 04ew56nbxylat+dnsistance 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 resistad 6l.sj3q sv2sr 4v*pns fd/7gnce 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 tosi1vr6 ,dipi.tcde; 3 a battery. The time constant for the circuit re.icvpt ir31;e,id6 sdpresents 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 inducthiyv+hu90yx za et)cyb+md;+h) (w q6or are connected in series to a battery. The battery is suddenly removed from the circuit. The time constant for of the circuit represents the time required for the curre(+h; wy h txab )d6yzeu+c +v0)9mihqynt 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 s gdl3hlod5; (dp y8lr6ame units except:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connected to an AC power supply. On this circui-e,v-)jdxhzrvw0 cnr- e;xl2wij +5t/ af :xut, 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 c/ ty6b6 *w,e jqbec.7rzmexp3f w ,;0w9ed fmiircuit, the curren*97x tw6wbejp ye q, ;cd wmmerfe,60/. i3bzft

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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 hfg:b )2xopj c3* )07j nqzf88 wcpio+m6gtcwby what factor when the frequenoog x) ij3zq6*w)8pn0c82c ftjg+ cfbhm7:pwcy is tripled?

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41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the frequency of the AC voltage a k6 *jysxe d7r62;nxnkcross an inductor is doubled, the inductive reactance of that ink7jd6 6xs*x2yrk ;n enductor

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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 a0 wgbi7 3x:jwwn inductor approaches zero, the inductive reactance of th ixb3ww: gj7w0at 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 con6v(jvj74 1ckpyp;k r tnected to an AC power supply. In this circuit, the curre(1;tvjrky4c j7 kpp6vnt

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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 circr)0 )a,*wohs.2l2 mqp xumyieuit changes by what factor when the frequency is tril. mpuqe )sy*m2r2ia o)0,hwxpled?

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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 n,(z z:ov9yk.mcjdq ;capacitor approaches zero, the capacitive reactance of that, ydv; 9jozz.mnk:qc( 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./ ht7x tpsdg c ne;cee;l5(g3 inductor and capacitor in a RLC seriehe( eec tsd5t /cp;l.xgng;73 s 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 +:d(uu2z hwtpv*zawz.-8qxq 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 impedance of the circuit increases if R increa co5wn wspkb ra97,v72aa ;v3ases. o9c5nb ka2a3avv7; prw , 7swaWhen 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 tzlw2b n .-hr7im5p.jof the circuit increases if $X_L$ increases. When is this statement true?

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50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC series circuit. The impgf7 qno: oqj( otvaqcz4.(n1-edance 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 circuief)ujx2sg8 i4t, the resonsg4) ex82ufji ant 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 drv/:nd h2vb v )icjh)m6f1o ra7iven 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 oc+w;w gnrpk k.-curs 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 rotatingx z1yr:x4 un8jky*sq0 in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are para jy :8qxnk4zyr* xs10ullel.

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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 magnetic5.v2nlo4;.sw fns:vz 4 wsu 9m9a krva field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are perpendiculvrfv4s5w4lm2:9 9nv owk a ;ss.u.azn 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 radius 0.10 m is rotating ipahe*rll-4 ;un a uniform magnetic field of 0.20 T. Find the magnetic flu4*l;pr ae-hlux through the loop when the plane of the loop and the magnetic field vector are at an angle of $30^{\circ}$.

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional area o6hwwg7-p+ ew amwz 1/ef an adjustable 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 from :yfw.t -d f3qplfc-e- e v9pmm36fy 7n$4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a square frame with si0u ymmuodfrz 2 /5z,43dsqwc+g zjy8.des 18 cm. A uniform magnetic field iq gmyw/d+04r j3dm.z2cz5, yf su8z ous applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the average value of the induced $emf$.

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61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A square coil of wire with 15 turns auc : 0rkq,.xmbh8*bbjnd 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 areayz. 2 xh7*wxsz9t hwr6 $0.20 \; m^{2}$ 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 wmam ,9w3ibzkrjji48*ing span of 60 m flies horizontally at a location where the downward component of the Ear,mairk3m *9j 4wzi8jbth's magnetic field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar that is 2.0 m long 4o31(-jtkwqucr4u x j rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while in a constant magnetic field or4x o4jucjquw 3t(k-1 f $5.0 \times 10^{-5} \; T$. 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 area oflq ,i00; qbh0 b;monmu $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns of wir1s-cqld-z7ab x a-rl7)ei 5 awe 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 loopsc glm/6 h g-e;aqs8 ufr:)(eka 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, what will be the maximum output voltage of tea8-lcu ;gqag:6esf /)m (rkhhis 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+ue )::fs 2opxecaeu8 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 98 qgvg-3y zehAC generator with an output of 12 V maximum when rotated at 60 Hz. A magyq9gg83z -v ehnetic 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 p9b,nvg5/ mua78k3f 7p qadgd 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 mo8y-yu6xw s l3otor 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 moto8nflf)klojl6s-/ r+vr operates on 120 V AC, and when running at full speed it ff8l/ ll )k6srn -+vjogenerates 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 aqavi66d 9i7ix3 te6l m 24-V power supply. The operating current is 1.0 A. x tld9376m vqiiaei66 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 amhke.3fe4)k 6tfz-s c 24-V power supply. The operating current is 1ke .- 6eh3s z)km4tcff.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 68/(oag6d pvg3ms k ;dw.0 W is connected to a 24-V power supply. The operating current is 1.0 A at full speed. What sakp( g8vw gdo6;/m3dis 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 priavpx:+: -md wumary voltage of $120 \; V$ AC to $6.0 \; V$ AC. What turns ratio is required?

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77#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  2.0 A in the 100-turn primary /.q(i (ccn0fhi4hajlof a transformer causes 14 A to flow in the secondary. How many tunqa(ci f/ 4h (cj0ihl.rns 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 necessaryle*(xeu /+ o eeb6xa2r in a 110-V primary if the 24-V sear *+lbxe2 x 6(eu/oeecondary has 100 turns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consists of a 500-turn primary coil and a 2000-turn secondary co;ad(jn d(sv b .ymoe3r:m9+epil. If the current in tvddb ((myn +3p.sj;me oe:ra9he 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 prrtr3/ s.9x 0xq gvwwp5imary of a transformer. Assuming 100% efficiency, how many amps at 24 V can flow in the secondars /g5wqx 0w3tx9 .rprvy?

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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 tr;.zr d5yz gkx+ansformer provides 7500 V at 10.0 mA. The primary coil operates on 120 V. Whatxyzk g ;.d+5rz does the primary draw?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coil and 300sy1 ietp 7w,f,a t5g(e turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is present in the secon seywttf 1,g7, i5(eapdary?

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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 its bvr hq0m8+q-asecondary coil. If 120 V at 2.0 A is applied to the primary, what current is preq8vh + qramb-0sent in the secondary?

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84#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has 2 gi6w3ww8ixu 700 turns. If the input current at the primaui8ww i6xw7 g3ry 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 secondarys f.oyb6/fqu:v a5y12d o4yls has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltag12 ouy6/yv a4lq dofby5:sfs.e 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 t(7-lo qvhrd) (+2hn-npb u ryuurns 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 to be (neglecting frictionaludrr7vq()b-( pn 2lh -y+uohn 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 is usually stepped sabbn 11rz 55cup to 4500 V by a transfor5as cr1n b1z5bmer 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 Vcxc22y88c. eyt9 gdck . The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of tota2ycc8.tk c8 x2 dygce9l resistance 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of cux -m m5o4u-rszw,o e:vrrent at 120 V. The voltage is usually stepped up to 4500 V by a tranormou, z es-54 :w-mxvsformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lost in the transmission line if the voltage is not stepped up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a total resistance of 0.60lyquj8 v ass.*7 oh.o+ W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of tso.v7 .8yjuhs l o+*qahe 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 linvk56e6anaxog efe:o r990g a- e 50 km long has a total resistance of 0.60 W. A generaefkaeo vxg099e5: -aoang6r6tor 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 less power hfm;m :rvvc )ba16t( c0ecqw/would be lost if c;qwmfrvvat/)h(c 0 e:mc6b1 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 A. It is to be transmittwwig): /z6xdnlpw r-* ed on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a transformer i/-w wl 6iznx:wg dpr)*f 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 mtyy g*f -(j(ltg l3n*gpz/99n:c kz nenergy is stored in the coil's *n-jg k(/lzcyn(3 * g:nytmp9zflgt9magnetic 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 an 18-H inductor. Wwpig)9vo6 8xn d r -/,nylpu9uhat is this circu y9ppo,8/ 9-ugnvdwln6r ui)x it'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 whe 1mwnsp6 wzt*, o.dr4gre the rms voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V o0uj2h(80dj hc01 uuevuqs;y 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 120-V AC outlet. What is the resistance v t8p k.gh ni 1dywsd5t6:g5r/of the lam5p wrs :v6ydt8g5/tn1g d.hk ip?

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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 powevyxqthu2)yp9j 6 cd*. r supply. What is the peak current ud*) 2vyjy9 6xh.pcqt through the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supplya)k(06 exhqk+ihdz: i6p q y-n. What is the power dissipated in the qaypk nzhx:(+-6di 0 6ki)hqeresistor?

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101#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor ispvf i p1-ex7/nsece0 , $I = 0.80 \sin (240 t)$. 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 resist8 wsb(j3pe jr8or 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 reeop8 ry 7o1.xwsistor 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 inductor agrqji4( f+ :bfqf0 0y cp1qgo.:f+ qqzt 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 kglzs50vju*m :.n.rn 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 a7 fx s,g8q: w3g8hy6 plus ee9ygnjv7: 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;0 x+m zcr qyp3. xbpj3z8ih2p cqv6;o 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 induct dyff:,*zlp y3a,gwe1 or when 120 V AC at a frequency of 20 kHz is appla: yg,pelw*,fy1d3 z fied to it?

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109#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 2.50-mH coil due to a 110-V, 60.0 vg;8 yz ,dam2yj0 gk2(qa s0yvHz 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 1na+( s i;if,k;d:m xuf0 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 10n 8yducut 95+d 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 reactance of 1200 W- p(azvej.ye) ?

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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 cap,c j3; xpw0uweacitor be 100 W?03pj uxw c,we;

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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 capam guy +pcu(*0k(5nra tcitor at 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 sq:/x doi8/f3l(*v7xxhd 5 kvvk9 xiz of an ac series circuit with 12.0 W resistance, 15.0 W inducti/8hqkv foi 7 :3i59xvs(zd*lxdk xx/vve 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 Hzqvkpzuo9c0)f,8 +n w x if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in seri+po) 08z9,xv qck nwufes?

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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 1.0-mF ceeu+z3eh1**m o t)vjhapacitor are connected in seriesom)tejh+*1hez3v *ue?

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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 induccb.mu5q ouk8*tor, what is the impedance o bu 5q8*m.uckat 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 series with a 20-+9rddm.najwpa5l5o ;r yx) 3vmH inductor, what is the phase angle at +md )nawxjyp ; 5lr5oad3v9.r1000 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 and 1.0-mF capa dg-1*3:f+ljbcq kyj mcitor for a total impedance of 100 W a*m+1-3 q clfky:jjdg bt 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 nee/i8 eb. jetkfutj17 :zpp :qr6ded in series with a 100-W resistor and 15-mH coil to get a total impedance of u . 1jpet:j7e pk/:z8ibqftr6110 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 inductorms 0mknl09c; g at 5000 Hz for a totalc9 m0smg0kn; l impedance 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-MHz fo9c 8*n+ri6h -faaylu rr a total impedach +lir69n *r auaf-y8nce 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. W eb /o 0.olm6vgx)7fwdhat is the impedance at 1000 Hz.vw 6m0eg fd) ob7/xlo?

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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 c9 :az5d0 udmokvr ,lw/apacitor at 1.0 kHz for a total imaodvd m r:,/9l0z 5ukwpedance of 45 W?

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126#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-mF capa)mdvz 1/ r +-tytxcyvbvtsg ye46o4 (dx ao5*2citor at 1.0 kHz for a phase angle of a(tdmy ovdg )14x*2r s6cvoe/y4tv-yt z5x b+ $40^{\circ}$?

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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 7g*5h0 vgw:pf/ ufcl wkHz for a total impedance of 4g7v w:/pu0hg lfcwf5*5 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 120 Hz. What is the phaf(.pdc ,hc7 vz( awc4fse angl az,ff(w.vdhc74 cp (ce?

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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 ut6r wdpa0sbb 8+4s9 nif a 100-W resistor, 20-mH coil, and 1.0-s 9btsn +r04u86bp awdmF capacitor are connected in series?

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130#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit consists of a 100-W resistor, g7:rm 6 jqas i-6;85vpwhffv fa 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-56;ispq fr:vwf7g -mvjh6 a f8V, 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 reactance 30 W, and an inductobn;. jr.3x u(ddkxzj(ptv7x. r ofv d;3 xj up.(7xkjd. b.tn(zrx inductive reactance 30 W are connected in series to a 110-V, 60-Hz power source. What current flows in this circuit?

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132#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle for a series RLC cxx 19lhy za8tbh;gw+6ircuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when ;a8xy 6hb9g h+txw1 zlconnected 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 resistm +0m jm*q:,yf.7au 4xblz;khr;vhteor for a phase angle of zhlkmxe;0huf7mtvby: .*jr+qa; m, 4$40^{\circ}$ 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 W8n kp8:v+ vsjc, L = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferred from the drivingpkv +8 jvc:8ns source?

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135#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power output in an ac series circuit with 12.0 W rm :;cnfk-tl vde)0zq 2esistance, 15.0 W inductive reactance, and 10.0 W capacitiv ;0)d2qlzc: -emknvtfe reactance, 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 cir yhr4ixi70+idcuit is $63^{\circ}$. What is the power factor?

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137#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ac series circuit has an impedance of 60 W wv6 h/am ),iluand a resistance of 30 W. What is the l/ a,u6 iwmh)vpower 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 circ9 revksdm 1a,m5j/ eg:uit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected tog:1 eksm d5ar /,mvje9 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 3*tl .mwa z*ucrekg71-mF capacitor and a 15-mH coil in series? 7 mkre*3cwagu.lz1 t*

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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 4.1r w 2xkw8arq87-mF capacitor for a resonant freque8krr q21 wa8xwncy 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 x,k1aw 1fmbafo : lb+wgs4 39minductor for a resonant frequency o kbw31mbg aox,mwal1+f s 4:9ff 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 cz qc0pi 9+x: is)py;(e 0jejgresistor and a 40-mH coil if the resonant frequency of the circuit is to be 1000:sg)jyp iz0ic(9 0ee pjqx;c+ Hz?

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