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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 mk9bj( tld 6ns5lc4(p(mq8li9/c,/ mwswl c t cagnetic flux except

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction statwe0 xu cbefyou2 ,)syebd.-:,es 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 what kind of changafvpgm7c zi2z,n j6n j1i3h8 -e on t6f njzm hj- z2p,7 cv3gai18inhe induced $emf$, 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 wha n1 ksnfa4(qw+t kind of change on the induckn+1 fsa wqn(4ed $emf$, 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 changefvqq92b7ku)dd n0 lp 2 on the induced f20nq29ld7)dkup qv b $emf$, 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 magnag )xe5bi2* r ce2wdx:etic 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 direction of aegd 6wk+ cbk xc).h,,b/4mpokn induced current in a conductor will beh,6bxo kcp./+wgkmk ed4,)c b 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 horizontalq2mnwfm(-h9izb* 1 t xyef8+w table. A bar magnet is held above its center with its north pole pointing down. Tfm9w -8 h1m ztny+* 2xqbfewi(he 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 helnkin j5/( uehgi* n81f lm3g:jd above its center with iti nn n gi8e(5/gmh*3fu 1l:jjks north pole pointing down, and released. As it approaches the coil, the falling magnet induces (when viewed from above)

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10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a table top in a region where the magnetic field vectorrku;k2zc r gk3 *u v0vgu8io49 points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the inc3k kri 0gukv uo29*;vgu8zr4duced 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 where the magnetic field vn75 i8dr8lggtk4. elxector points straight up. The magnetic field suddenly grows strongerk8t458lr g ex7ni .lgd. When viewed from above, what is the direction of the induced current in this coil as the field increases?

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12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a horizontal table top in a region whes2*dkoqng- k.+trv n; re the magnetic field points straight down. The magnetic fi;nq+kk-.ntgdos 2*vr eld 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 horizontal t az(,tebj6 hx,i1q+onable and carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either side of the wire. When viewed from abotnb,x6 1+hqi zje,oa( ve, 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 n yu 5 9lslqmyk:dlxn1ng*8g(k.4p; syorth pole entering first. As the north pole enters t l(skl q 8y.l*p1n:95y ky;gs4x mndughe wire, the induced current will be (as viewed from above)

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at qtcd7+x /iy gmm db:ufwl (y(7-t))cs 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 ts ):qcg/t7ibwf7lycx ) y dmu(-(md+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 constanz- b8ao 9geo25bok s-hoso67bt 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 ori5o7kbob2ge6-bahsz89oo o s - entation 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.i- vxs:uaau1*
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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 anji507es3ah-hw bgiy/r4ve k, $emf$ 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. cibfv7hsgu /, ,)azkebx*;b698vitd The $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved northward atcpyyx975 je86 qt )nvm constant velocity through a magnetic field that points straight down. Make a statement concerning the potential induced acros5)yvj t7xep9m nyqc6 8s 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 angularb 8l2uj3ktjuus/ *w juvw )+c4 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 generato,a7qgr ct,h( f8hsupb v4/6azr 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(zizkns(q l v jlkl -n;zid 7k:*kx7+- each second. The frequency of thv(n:(l-n kk;q7 klki z+zzs-i* x jl7de $emf$ 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 devic)yv3v j;g0 to;s j/wqe0dv6kxe 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 thc *bp6nr o1u*nat

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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 /2 4eqi.fdqh.e (z8kv azhsl; the secondary coil contains more loops than the primary coil then ite.sf eh( z.q;q 4 l8azhki2v/d is a

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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the primary coil contains mo 1)latobg)h6a re loops than the secondary coil then hato6alb 1)g) 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 p7;:rq oeca5ox ower 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 circuity*mqo r ;l9duz v-0fh5,

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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 inducto4e-4bmkye*kxq *e ,tvr are connected in series to an ideal battery of constant terminal voltage. At the momee4* *-tqbkyvm,xek4 e 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 inductor are connected in eia a/g/, ,boqwxncce14k -d)series to an ideal battery of constant terminal,/cbinwd1gae4 ao ec-x /q,) k voltage. At the moment contact is made with the battery, the voltage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is connected ton2hix3oe d7f 7+gd7a lj -;g,n/ugyk u 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 resistance R is connecyun7o0*e m1rvw:m(kay5r5e rxqmk)7 ted 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 connecteof pv.mblwl7d (2p3)+ ih3 xekd in series to a battery. The time constant for tx.iv(pb 2wf+l73 e3d)lmhop k he circuit represents the time required for the current to reach

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected ie-wg nt:aoqb5)g;(py . aj)r0hzz *atn series to a battery. The battery is suddenly removed from the circu ez hq ot*)aa5-:; a)nt(gw0rbyz.g pjit. 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 except:)(tc4aq kn glz3j id;2

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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 thse8c.uesbu3mk8iu 9 4is 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 t bxqr r.+a+k lr4io(i/o an AC power supply. In this circuit, the currenlrxqo+ r4 ib.aik/r(+ t

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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 wh rmhu3 ,+b6xhfen the frequency is tripm6xb ur+3hfh, led?

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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 do1kxhejts.u1p9e u+r,*20tzvhk g *jwubled, the inductive reactance+ 9.uk1tgxeer uk*s1wj hv0ph* z2tj, 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 zero, u1u,1 ppb67j ;qcamrythe inductive reactance of that p1 jyum7qcp 1,ubra;6coil

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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 cqyq wm .c0sp6g+:sak g4* :qxpower supply. In this circuit, the curre6 s. xp+qgqs0 mgccy*4ak:qw: 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 thsc9m 6asr az0-a,9lnpi x*ob 3e frequec sorixpz6n9b*9, as0a-la3 mncy is tripled?

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across a capacitor approacz7 7vu2)erj1:wiz qdehes zero, the capacitive react7q1j d i re7v)uz:e2zwance 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 between8/zv+nvqdf mnccm448m 7c 7wwk8yuc 5 the voltages of the inductor and capacitor in a RLC series cir7c/ cy wcmk v7vnu n8 mwdf4cz+8548mqcuit?

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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 wjl7p/:pj+qj 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 incj/ykv ;pd-6h hreases. When is th;vjy/pkh 6 -dhis 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 y02c/ ,ud k : giw0jw7g6iimj1wnmd-l3 g,of tthe 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.6oj 8ju7qma) b 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 tcnwc/:xw s/w nu9* so5he capacitance both double in an LRC series circuit, the resonwo5/9 /nucsw x*:cnswant 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 dris61-/uke3* e q4pnn.nh tnsksven 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 cirt+cq1 +vt(y nbcuit 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 rotat-mmq o ov8j7, 6hvrsi1ing in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loo vhvsr -6187,mmjioq op 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 radiusonjr9x:g oq/t ccjj4 03 0s p.ize iaqxuk/./( 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the.j(k/xxs /jzq9j qr i/g:ep4tc00ci3n .o auo loop when the plane of the loop and the magnetic field vector are perpendicular.

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57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radi8efmkyn akx8at/.,cd 0w1q9gus 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetiwd 9atf1axq. gce, /n8km0k 8yc flux 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 of an adjustable single loop is regw)*p v+rhj5)fy dm +8e .eoykduced 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 ch/eko)/f; ) xy2 enizrzanges from $4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a square frame with sidwod bwx lp;:4 tfhvq:/x1 1yo:es 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 of the induced ypod14/w:b xhwv ox;tl::1 fq$emf$.

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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 wirev /xr*he5pe7 2ipzi( hf7 s zg-k6roq6 with 15 turns and an area of $0.40 \; m^{2}$ is placed parallel to a magnetic field of 0.75 T. The coil is flipped so its plane is perpendicular to the magnetic field in 0.050 s. What is the magnitude of the average induced $emf$?

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62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil of 160 turns and arpl ay2g ta8.e4ea $0.20 \; m^{2}$ 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 horixo22) r yq++m5jrci7p1*krr hy.dcwuzontally at a location where the downward component of the Earth's magnetici+5w* p2h cd)k+r r .urjmc1y2oqyrx7 field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar that is 2.0 m long rotates at a constant angular vecb;( z 3krzmt0dx*md5locity of 2.0 rad/s about a vertical axis through one of its ends while in a constant magnetic fb 0md35*(x zzrmckt ;dield 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 loopskl1 gy23jn3sx(4 :uh(qkvwjsjm nc, , 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 turns of wire oft-5lr 5b ik x(9nbocd5 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 on its ar. 037omrnc bcse)fy emq9j;ozh z2-+k mature. Each loop is 12 cm long and 8 cm wide. The armature +rm e-c73o bkm zf9nzyh0.;co)sejq2rotates 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 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+m48lms4a)b2 oh heiof 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 simplezx du19)z tmspu80a- y AC generator with an output of 12 V maximum whenzap1t9 us-)zxmy0u8 d 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 maxixmlvge1 aab4 b, zck) 3yrn)st2o ;;2gmum $emf$ 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 6.08 vxy5oywo9e 5gudad zy)9 p*00 W. The motor operates on $120 \; V$ AC, and when running at full speed it generates a back $emf$ of 105 V. What is the starting current of the motor?

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72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have a resistance of 6.00:3yneb zdi2 x/fes 4(hs9f3d g1d 1avd W. The motor operates on 120 V AC, and when running at fulsse3ax(d4i: zbdv21 9ddyhf/eg1 f3 nl speed it generates a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to oa+tzuuaf- bg(i90s * a 24-V power supply. The operating current is 1.0 A. What isatgb 90i- *+ f(oauusz 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 /9+z-mt ri7zp eiil5qW is connected to a 24-V power supply. The operating current is i/5mi9t iz+7zr-epql 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;g)w epwbkyc+8z sw6xr 1,w ;5cjrb,s 24-V power supply. The operating current is 1.0 A at full speed. What is the bac,8; es; bw51w,6jzp s rcwyb+ )gwxcrkk $emf$ 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 vvnvz6/4 wx5mgdspje g1 m -w-57rq.rboltage 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 A to flow in the sei i79u5a rr6ercondia ru5 9ri6r7eary. How 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 anw :syo0chl(byq k8d3x642x are necessary in a 110-V primary if the 24-V secondary has 100 tu lxxo6h( ba23d4sykny:q 0cw8rns?

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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 secondar-hl l :j0v.qmqy coil. If the current in the secondary is 3.jlm-qv0 q.hl: 0 A, what is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primary of a transformer. Assuming 100% efficiency3v h5c0hfox)ej t ;0oy, how many amps at 24 V can flow i hjo e0f0;v)5oc3yxt hn the secondary?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The secondary coil of a neon sign transftkcyl-r5cv*0b zv(yprfj/ a51 v,.woormer provides 7500 V at 10.0 mA. The primarrbyw vl5 k t v*j/z0f,p51ca-ry (ov.cy coil operates on 120 V. What 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 c 1si. rlqyxs r-)h.+;itxebm n,m.e,300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is pre, ;sr-slih exmq m,.ey1. c .+tx)nirbsent 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 hz7m8(o) cmo0dc iada +3(yhmias 60 turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the secon zd mo7om8 dmhc i0a(3i+)yac(dary?

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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(ibhi j6t4 i4lg. 5ml+pwfs0+fi :oy n 100 turns and its secondary has 200 turns. If the input current at the primary is 100 A, we can expect t 5lwo(tgi.ym 4hpb6n ji4+isf +f0:l ihe 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 sqxy74*ux;ct z kx42htecondary has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltagey; kt7zqx h*xu4 t2cx4 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. If9xh3eh6sh9 ye4q1ajv the power input to the primary vshe 694 hhq1j9x3eay is 100 W, 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 cu,x ,kjeu,wl0yb 4uo0 krrent at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitwyko4 kb,0,x jl,ue u0ted 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 indwk.mbn ho056h j1 z+s usually stepped up to 4500 V by a transformer and transmitted through a power line+hond10 5bm6kn whj z. of total resistance 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. t,xxo/o m g 0vcbl:gr e)*eu,+1sd jz3The voltage is usually 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 voltage is not so dc,v o+g :1g0ezue,t3xj blrm)/x*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 re9 86aimni) x:uqt uo)vsistance 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 100:1. What percentage of the original energy would be lost if the transf)i 9i :axt8omv)6quunormer 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 rpym.;v9a p -ixg tw;;to*:s caesistance 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 100:1. What percentage of the original energy is lost when .vm apyw;o9scxi;tp :;g*ta - 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-k5m8fkoi klk / w.xr 4otvee4*ff8:b 6-W line at 1000 V. How much less power would be lost if the power were transmitted at 3000 V instead of avbk88k/.-xel4t5 r*iof ofe:km4kf wt 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 4p+4igpaa d1 i nn5zm8to be transmitted on a line with resistance of 0.60 W. To what voltage must the generator ou415 ndgn4ia+impzp8 a tput 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. Hoq4 0dc )ejlil*w much energy is stored in the coil's magn ecdl4) l0*qijetic 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. What is t mzba2-f.vb(k2x w1 v5z)zr oyhis circuit's time constantzymz (5k)-b2.f ra1zxw2bvv o?

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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 -eg1a ojlj70x1f jg;x ly3u/u in an 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 into a 120-V AC outlet. What 9w;q1 vk/ssweis 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. aqdprr s3mj 3cx-9 .9x What is the resistance of the lamp?x.jrr 93d-c 9psax qm3

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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-V0wk/wie: pdeuoe 0 annh3- k(9 ac power supply. What is the peak current through the rednk0n iwoha(-9e/ ek 3epw0:usistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. What is thr0p8 dn)flan yuz5,d3e power dissipatnd)5uz0f,yrd 83 nalp ed 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 ax u 6t 5zhsz *n-6qnjtem32m450-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 resistor is gqjesy(uf*, ; $I = 0.80 \sin (240 t)$. 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 resistor iza:k( es)fd)x s $I = 0.80 \sin (240 t)$. 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 induc4e kguub aik0)dx 6o:)kxl79i tor 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 10j+kbz*86pms uag 1+xk00 Hz?

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106#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will a 14.0-mH coil have 14.0 W of inductive reac)u9d) i znh;b aokut ./pr3i.jtance?

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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 indc) 9sz.x n kintj(qv6(uctive 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 frequency of 20 kx bm0j ; hpmd pf)w6 0bw8zhqk6sd(*a6Hz is apxw0d h8*(w 6d km)q6;jfb0zmaps hb6p plied 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 Hz s-b+efdb6e+q luukj0) 3xaz9kk 5o m t/ource?

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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-qfp,ussh7 a,: 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 reactanc 5)yuq4g q vb/lcko0p),+mmoi e at 10 kHz?

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112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacit8a * wc)zfhx3skik-j 5:5pb utor 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 reac sfqebt1q;tv59 hpk)d *3 w(pxtance of a 0.010-mF capacitor be 100 W?xt1k)9q 5pe t(vdf wbp*q hs3;

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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-mxtl h7b0+a) 9msonu394qbwwecj/ rz0 F capacitor 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 of an ac series circuit with 12.0 W resistance, 15.0 Wfl0 lq)hh791uaqe m0p inductive rq9e1plhqa m)u7 lfh00 eactance, 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 impeda,lz ef r13npl(nce at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in series?p1z n3,rfle(l

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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 co rg,r2vnb).h1keu4xf ,nir)ail, and 1.0-mF capacitor are connecte,4rnb ,nr1x2 .h)vurg )ekifad 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 /,nw pies)p9xin series with a 20-mH inductor, what is the impedne9, ppxs/w)i ance 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 connected in series with ay2/sxazi pfx ;l/h/x/ 20-mH inductor, what is the phase angle at 100xx/ ;xlys/a/pzfh/ i20 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 cir6/r; zst wn ewh)wym,7cuit with a 20-mH coil and 1.0-mF capacitor for a tothz/ ,6re w;yw ns)w7tmal 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 needed0) v0rfls3fu w in series with a 100-W resistor and 15-mH coil to get aus300 fv) lfwr 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 5yot )zbi13tk-hx4-d *wv s fzo: jl(l8000 Hz for a total imvjz :8i klt 4shz )f(xb*o yo--wlt31dpedance 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 bj5a9c;icqbzo .slp1tj4w+(s sv): zte put in series with a 100-kW resistor at 1.0-MHz for a totat5s+w1 bz csp4l j;:. (joz)t9cqvs ail impedance 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 seried hdlg4p.)p+* zbpdd*s with a 20-mF capacitor. What is the impedanced4b)l*h zpd p*+.ddp g 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 k,i( jqmzdz8rl6 en*2in series with a 10-mF capacitor at 1.0 kHz for a total impedance682z,z qikl r(jmd* ne 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 cxlupiy 6 1)k5ko7ws.dapacitor at 1.0 kHz for a phasex5 i1l.7op6d kwy su)k angle of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is n)+( sz g.kkuu.9tn m,jyzt ,h6sy;vh teeded in series with a 30-W resistor at 1.0 kHz for a total impeda.mvn st;.k6hztg u, z9+htk(y) jy,us nce 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 1-pf-sraw l 87s 6pmbz(00-mF capacitor at 120 Hz. What is the phase angp-rab8mzl(f wsp7- s6le?

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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 i+/ (kzr.taobif a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are cot/(.bo+zrka i nnected 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 cohabd44cxms a9ym3o46 xf kx64nsists of a 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-6xm mo49sc 3bayk 64axfdx44 hHz 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 Wfz(u, ;wug 1jg, 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 power source. What cuug1z fj, (wu;grrent 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 circo .4a/4q w7mc4djvmxi uit containing a 50-W resistor, a 10-mF capacod/ 4i.7q4mmx4 w jvacitor, and a 0.45-H inductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W resis8p)lhcmj58lr: e - ghotor for a phase angle o c r8gmj-e )8h:l5lhpof $40^{\circ}$ at 10 kHz?

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134#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit has R = 20.0 W, L = 200-mH, C = 10.0 mF. At0:o ,olbim1 pzn nd1(c what frequency should 1min (plzb:1noc,0d o the circuit be driven in order to have maximum power transferred from the driving source?

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135#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power output int jjc()0 1bhqyimf07 w an ac series circuit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit w7iq(bm y) j1hjc00tfis 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 c p, cmg 1xdwjmcr3j/57ircuit 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 hasrvqi05 8gxvoj,u dh; ,fnhk .7*h(m kuydd f44 an impedance of 60 W and a resistance of 30 W. What is thu,x4i gv h8 *o.7kmqdnffhjv4r;k dy,du 05(he 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 ci8 -uc eq*ul x,liq5pp;rcuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 6 ql;c5x qu,l *uiep-8p0-Hz power supply?

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139#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the resonant frequency of a 1.0-mF capacitor and a 15-ka )wf(v ;)dydmH coil in series? y(d fkv;wa))d

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is needed in series with a 4.7-mF capacitor f8 sblt61)flffhh f5n-or a resonant frequency of1) l s5f6fbht-8l hffn 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 c2m9o2hilv*ag:cp; a rq 1e 0aneeded in series with a 3.7-mH inductor for a resonant freque2g1qcr ;0hi:a cealp9*v mao2ncy 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 3041p,7gwj fyvto+c - 37itno lz-W resistor and a 40-mH coil if the reson4 i z y-vpftloc37gn,w+1jot7ant frequency of the circuit is to be 1000 Hz?

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