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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 )tv*(c jhe.qqco y)w6are units of magnetic 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 statessh3w; *1ob 3m zue6h(dyma )jy 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 chanv n6; b-odgr-qe2m,4fset3epge on the inducrgefmeqnvb - o6t dp;-s,43e2ed $emf$, 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 throuaa kl fi 7935pz:7mchjgh a loop of wire produces what kind of7c j97mpkazlf ha5:3i 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 wire pro 4 u(5n28 y;z-lgy5s 1ehianxo;sk idrduces what kind of change on the inducedr1 4nhugdyx5y n;e 2 (;ois5k-is8azl $emf$, 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 removedso9lx2q3m qs1gun d3 . e.as+o from 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 law, the direction of an induced cu:8xs ry*6qo3 yui) hbwrrent in a conductor will be that which tends to produce which of the following effec3q xwh*i: y86 obuy)srts?

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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 ;w,t.wc sm z8-o(javc a horizontal table. A bar magnet is held above its center with its north pole pointing down. The wmswc(z, ;c8v. at-jostationary 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 k b6 ,*riyd)a0+d cmoka horizontal table. A bar magnet is held above its6,*dri+k y a ko)dm0bc center with its 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 venn.muii8(r 7 ictor points straight up. The magnetic field vanishes suddenly. When viewed from above, what is ti(7.n uii8n rmhe sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a le vp8m3+kxh b-9 almd ze65l2buvel table top in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. xbm h za6lp8-ml+3udbk52ve9 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 hoge 7 p vqw:; p9ei./ewpsad;t5rizontal table top in a region where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, what is the direction of the induced current in this/w d: ps;aptpev7egwiq;.5e9 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 horizontgnpy:3x a 1dfbg22y9mal table and carries an ever-increasing current mgy2 x b13 yaf:dn2pg9northward. Two coils of wire lie flat on the table, one on either side of the wire. When viewed from above, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls through a loop of wire with the nortx0cv)4aa..ys 3bb nooh pole entering first. As the north pole enters the wire, the induced current will be (as vo .ab.b0s ac4 ox3y)vniewed 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 cqbx8suk *0( b2 imz;wyonstant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, 2s; my( 8xiw0q*ubkb zwhat 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 8hc+a15 s yulztnd r5,rotated 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 rch,lrdyu+a t1s 5n5z8otation 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.p0 k *w i z 9tp(kk j*+qr/)z*ufui5s)uyipap+
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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 an/(,bfen io 9*hkwp ,in $emf$ 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. z3m(d qtwsf 7dyc21r/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 mov txv)tep6 r;f7ed northward at constant velocity tp tex7)6rvft; hrough a magnetic field that points straight down. Make a statement concerning the potential induced across the rod.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal barokln7 )n)js9h wx a-.f rotates at a constant angular velocity $\omega$ about a vertical axis through one of its ends while in a constant magnetic field B that is directed down. The $emf$ induced between the two ends of the bar is

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23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An electric generator tra6ohv;ob05 stjjm2 vm ,ue)o,dnsforms

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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 eacz +rq +chceu1n -9,nmjh second. The frequency of th cr-+m,ej9qc1zu n+n he $emf$ 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 7x5xh. 7qnts /h3el ftused 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 thatg dx sxr: 5+xe9e;bmy.

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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 mo*y73(aupv4qc a3cf lqre loops than the primary coil then it y a33cf(v7qucaq 4lp* 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 mp2zkt7 puh,h 05 vi/wwore loops than the secondary coil then02/ uh hkpwtpz,i7 wv5 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 inpu*lg/gyre 6 nj3mn/i9n+p4qdp 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 4vffck,lvv3 ,h*lf e2 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 8q bpbpih/d42connected in series to an ideal battery of constant terminal voltage. Atpdq2bh84ipb / the 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 of*wbug8:)ievqx-8 m x .qnb9 +0 leomfxop00gr constant terminal voltage. At the moment contact is made with the battery, the voltage across the inductor bn* bvegop0qlue8).w80 g x qfomir+x :x0- m9is

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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 indd;yg- y,pkr 1,)whfaructance L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the inductance is 2L. When it is connected to the same $emf$, what will be the final value of the current?

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resist kut 2l(62urod )8jiapance 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 battery. +:yj+7mgrlkrxc3 : tz8kip/v The time constant for the circuit represents the time required for the mjvz:+ it: x yk7+ rgc/pk83lrcurrent 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 ak ( nc4nggr 4*uc1spu2re connected in series to a battery. The battery is suddenly removed from the circuit. The time c (gc pr2uc*uk4n1 n4gsonstant 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 4j/; 0qg h:b(lbwqul hunits 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 ci(u)8xf/a*ix jf vdt: ercuit, 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 thicl9:m /f al.c ,d:fjgtcb/ n5is circuit, the currenti5j gd /mlcb,9 .la f/n::ccft

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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 circuil3y n0kmolai*3 -wnhxg-bq,-c fu,)at changes by what factor when the frequency is tripl3 mllh3 ,qg-ycia ,wb k0--nnf) *oaxued?

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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 idd wz-yb: ( nn68lb6ats doubled, the inductive reactan(a8n-bd6nz6yb l:w d tce 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 v-ruc /a/n8xst3n slmef,78g i,i+ltvoltage across an inductor approaches zero, the inductive reactance o8 n - usxt8/r3+s/fiim,cnlgvet7 al,f that coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In this circuit, the curregt3;*i :1ihjqn 1ihzrnt: nhiqithg*ir13j; z1

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance in an ac circuit changes by what factor when the freq8yexu-p8 y id 4wkt5,rueny ueix d8t4pky8wr,5- cy is tripled?

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across a capacitor approaches ze,i+:aa vll t8jm81ijxro, the capacitive reactance of thatm8av1ilj8x:,lj ait + 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 ino 4h) s htz,jhuw*fx86ductor and capacitor in a RLCw,8hs4u)zfjh *t6xho 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 pgz(aoodb ;d *tm hgvc+:x2- 3an 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 incorglcw23 0yn:c3c c*freases if R increases. When is this state:323gcfcy * cwrc0nlo ment 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 imph,3 s-q, jsz19q ;qm hntph8qnedance of 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 impedance of the cirr;pb td+zs9 z myai qu:4hq76,cuit 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 j0x9utic2-uetv * w 5d tfy9j-the capacitance both double in an LRC series circuit, the resonant frequency of that w9-j ft-05tuxidy*29 jceu vt 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 driven by an AC applied voltage. At re r.ut27.cup- d:6m/bdkz9f+k landg fsonance,

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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 ca8cou phheyfl(c00n vq ya 2e/7 h8(n;ircuit occurs when

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

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic fi9wr.x-p0 bqb sd.hdc)eld of 0.20 T. Find the magnetic f .d.0dcbq9 wx)r-hp bslux through the loop when the plane of the loop and the magnetic field vector are parallel.

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a unif- cy1p (jwbjsg.v0 j*zorm magnetic field of 0.20 T.z.cwvy g0( -1bjjp*sj Find the magnetic flux through the 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 radius 0.10 m is rotating in a uniformw.qg:bqph n +) magnetic field of 0.20 T. Find the magnetic f.phq:n b wg)+qlux 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 singlem)v2rcd+g p ntk6,ps, 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 8g:a3vinf7 ray z*.ne$4.0 \times 10^{-5} \; Wb$ 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 witmhcs3;)yynilupy 6do rh0 ;/jx :3+pch sides 18 cm. A uniform magnetic field is ap60;hxilymh3s)n 3 yyc:r oc+ j pu/dp;plied 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 and an u:z*uu.5ee bmuf-o ya s 39e*iarea 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 an79ilve 0:rk)h+ q mtuh8.acw fd area $0.20 \; m^{2}$ 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 fliew4a fz6zw47 91c gescqs horizontally at a location where the downward component of the Earth's magwc4szg1 6weacq 79 f4znetic 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 velocip 3 fpn/li k1 r;;ccu-q8 tcwy(-kvi)uty of 2.0 radt u-rip/kyi-cu;cqc1(l fv) k8n ;3pw /s about a vertical axis through one of 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 (eiaixv9i. q/8 -rhh thas 50 loops 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 of.6ctmal+a ns b;p j0-q7i/cpt 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 armature. Each loop zt*3oy9 j e00har-ct(mpzdm + is 12 cm long and 8 cm wid9t3ed(0p m c-jay oz+*zrmt0he. 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 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 up484py 4z8bec sxl0a of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced 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 1jy;7di iat;d ..n 5wgl2 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of the di. jw t5;d .;ngay7lirotating 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 maximumyo/0f* d,mk3j1ws/ihrf m:so $emf$ 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 resi ee+;/ 0hgbxay .ogq2vstance of 6.00 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;6nb+kimxw26f9d2-k1npi uu . ce mbw resistance of 6.00 W. The motor operates on 120 V AC,f2; 6 +nwpm uc2ibxeu1din96m-bk.wk and when running at full speed it generates a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V 9)th2xp0q+ xukki;f s power supply. The operating current is 1.0 A. What is the start-up cfk0s2pxtq) xhi;+ uk 9urrent?

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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 connece,13scg* zv-8p(( cf dd *f nqkth;gfpted to a 24-V power supply. The operating current is 1.0 A at full speed. What is g vtc**pd 8(-n q(g1pshzc;3fdff e,kthe back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connecte*ngh8i e,aas(1 lk4ldd to a 24-V power supply. The operating current is 1.0 A at full speed. What is ,h*8(e k indal g4la1sthe 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 voltar8r ,w 9defzx(xtf6/;6j c lcqge 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 transfojv tbdk.eu-4 3s1le/ pvy6+ry rmer causes 14 A to flow in the secondary. How ma- pjyb 16el.v t+k4uys /erd3vny 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 necessary in a 110-V 1cdo,w3 x smw3primary if the 24-V secondary has xdc sm31o3,ww100 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 secondarcnypy p4rhpo,jk7.7 /l0ywfy8,th6dy coil. If the current in the secondary is 3.0 A, what is thpy wjhyto/77yp ,6f 4d0,8y h clknrp.e 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 tra*ql;6tzce g2 nnsformer. Assuming 100% efficiency, how many amps at 24 V can flo lcqeg6n2z;t*w in the secondary?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The secondary coil of a neon sign transformer provides 7500 V at;sub1*zcg gu 5:/3 eshp)udwp 10.0 mA. The primary coil operates on 120 V. What does the pr:pd)suphczgbew1g 3uu* s ;5/imary draw?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coil and 300 turns on its sesa3cnl ka: w ufe rm6.n)w5+)scondary coil. If 120 V at 2.0 A is applied to the .)s:lnaukn+3 6mw wf)cae r5sprimary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coi6g5(q zc.f9lrrnxn1w u0ih 1ol and 300 turns on its secondary coil. If 120 V at 2.lh x rz0n6.5(n 1c1io ufqwr9g0 A is applied to the primary, what current is present in the secondary?

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84#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns ar)aegc2tjtc a4n6b1z+t g ,8vnd its secondary has 200 turns. If the input current at the primary is 100 A, we can expect the output current at the secontgce4ta naz,r82 c+t6 b1v)g jdary 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 se2(wouys*mq 6y8ua;pzp z 4y* ycondary has 200 turns. If the input voltage to the primary is 100 V, we ca(u** waqz42yzy m6; pyopuy8 sn expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has*a 4* b:odiydu 200 turns. If the power input to the primary is 100 W, we can expect the power output of the secondary to be (negldoy*d bua* i4:ecting 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 is usu)rqftf06tb0v k,vme 6 ally stepped up to 4500 V by a transformer and transmitted through a power 06v)q t0rmf ,eb6f tkvline 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. The6f*na7c o0-w ra3 +v0g*iiqwizw zo;e 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 transmii7 iagwr6*z nio* 00cwa-+3 w; qveofzssion 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. Thn ssw+icjgi 29 8)z.cie 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 iczw)sg ij82.+insc9 percentage power lost in the transmission line if the voltage is not stepped up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a total resistance of 0.60 (ot jcua-k+0aq a2)vv W. A generator produc( ocjuvata+ k02 -qa)ves 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 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 s8lyq )mt8u0 ej.e;eda total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ) sj8 ule.tm;8d eq0yeratio 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 1003 f7 sfb) k7rphnb0ve8w:joo+0 V. How much less power would be lost if the power were transmefhnp708v b3:+wbfoo) j 7srkitted 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 o wkvme+:;7fb is to be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a transformer if thefbo:;wme k+v7 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 5.04:bkn+ euh,wk qjta 7s1 m+0fu A. How much energy is stored in the coil's magnetic fie et 7n+: f a4s+ujmwhkq,bk01uld?

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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 m6q a- jvxjl11this circuitxl q1-jm a1j6v's time constant?

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96#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the peak voltage in an AC circuit where the rms voltage ige(dh4jh5vf b10n/ ,gejpkt;s 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 ACn75k u 6rsoh8jp7dj9o.5uivh 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 8t pd7i4oo wvwjkw/7: 120-V AC outlet. What is the resistance of the lamp7t:j 4/ v wiowk8pdow7?

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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 power supply. ag9nxpp8n f) 7* sgerl +ixheliy,(33 What is the peak current through ther)hl 7 ieyp(p 3a3nxx8i *,g+l gf9nse 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-lq hf 57z7;umqV ac power supply. What is the power dissipated q77hu mflq;5zin 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 resi-s oqz-cv2ul,stor 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*wu eghci(xd*q) jr9 /kqh4 7hrx(wr- 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 resix :czxqo tc)-ho3+ iz;idibl14c m c55stor 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 indu. mfgz/6jfe0z/8 mbx hctor 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 10ws 4vhwh0eyi73h *y8f 00 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 reactance6zppvqv ) s:62do;b mo?

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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 inductive reactance at 1000 Hz?1:5l)(audllei olr-bowr b /*

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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 kHz isd s1y(cg sco5bn-k0ia7v7mkf 7q s3* z applied to it?skc*si7f0yd75g bo z- 7vsq3k(am n1c

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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 11 w -cpcjzbgwt(ju(9 z:i6k7w: 0-V, 60.0 Hz source?

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110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitive reactance of a 4.7-mF caqiy/m)j),pg5c3f plk;qw3s q 5u3wu ipacitor 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 r o ta3u 8zm u+ie,3f/r7leaeq3eactance at 10 kHz?

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112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacitor have r.b1 p ;ald v89xhxvr7-so-z sa 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 capaci n)ob 3*c td.oj:.d(kzf2 lsxxtive reactance of a 0.010-mF capacitor be 100 Wtn ozb.)x:s*( lcj k2.xdo3fd?

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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 capacitorupc6+w*4zu8 rlb28 htyzpo l- 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 ( jktnr,xt:-l, 15.0 W inductive reactan (x:-tn,ltkjr ce, 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, 20-mH coil, p+;b-o a+n. o 8xcm:tj wfus5iand 1.0-mF ca w5xo.:pcfaojm;ns u i +8-tb+pacitor are connected in series?

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117#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle at 1500 -lx* z ul1o4mrs ,wu6 e+(zcueHz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connecuex+ ml*r4-uu(z c 6,1wez losted 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 conn vt 1ck( wtqu;qu.*x,pected in series with a 20-mH inductor, what is the impedance at 10wx;q,u tuqk.cvtp*( 100 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 ;3 a,rcl)p t bp/x2qna13mmbu with a 20-mH inductor, what is the phase aq bb3pt/uxa cln ;2)3a, 1pmrmngle at 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 seriesy;pip(o(q3g.- aqd 6v b8 zpli circuit with a 20-mH coil and 1.0-mF capaciq3l i; y(zviqpbda- o6g(.p8ptor for a total impedance of 100 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed in series with a 100-W resist :qh(4)db sj.b d,hvmqor and 15-mH coil to get a total impedance of 110 W at 2000 qh4bs,(h .qbv:)m jddHz?

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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 50tuifnq q;e0 :txa(- kgy d+b3/00 Hz for a total impedancenfxb/uq y3 +:k;0at(eig d q-t 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 witjmr,1bb12n w vr c 7eys)rf-lpf w52p7h a 100-kW resistor at 1.0-MHz for a total im5ynrbjcf v rbl 217w-p2),m7 prwes1f pedance of 150 kW?

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124#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected in series with a 20-mF capacitor. What isfd:y .q :o jq)ep;5fnp the impedanc::ypqn jp; fde5q)o. fe 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 series with a 10-mF capacitor at 1.0 kHz for a tota n,- e2f jpd/mokgl)y+le-ln, m k+p/g) fo2djy impedance 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 capacitor at 1.0 kHz for cr4 d)li;7wj tnwg.ejiiy 1f, ca0(g1a phase ang0cjn(g)cl4, wi tf;.r wi1 ej1dyi7 agle 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 wg e8m)an5lm ,nith a 30-W resistor at 1.0 kHz for a total impedane)ma 5ng l,mn8ce of 45 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 120 Hz. s; 0z n7j o*fbk/8wdmdWhat is the phase angle?7/s0 bzonwmj;ddk f8 *

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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 orovt 1)s/z qa.d51u pand 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacito5urvosq atd o.z1p)/1 r 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 es 3q2:8n:5(u -vnnbfrws x4r imu2v l100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz powerrfui:s2u(nwsn 4v3:lx 25nrq8bev- m 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 inz.o3 rot:19t :i,ssb.uibr p qductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz power source. What curret.prb qtz:ior1,s: 3 b9us.iont 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 resiod*q uzn((8hd stor, a 10-mF capacitor, and a n(*d u(oh8zd q0.45-H inductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W resistor for a phy wcqp,w5hv3l e7o8m;7pw*lw 8 vt,ahase angle of , 3vlc,pw vphw h*5amq8w;8ywotl7 7e $40^{\circ}$ 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 /dlk(-q 2rmob = 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferred from the drivbdrl (q-k om/2ing 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 seriesb5ho eo5.0f bv1vhzk4 circuit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W cekv fo5 .v5h41hbz b0oapacitive 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 anl*f/uswpd8aw8yv 3 o. AC circuit 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 60vjm*f ;)60yga ipv0az W and a resistance of 30 W. What is the power fav 0za 6jyg);pvfa0*imctor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series RLC circuit containing a 50l7 s9twh52 xy:swk(wa-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power supply? k9w5s:w lxh 27t(asyw

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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 capac:6yd 6p ypuvh6gif53n itor and a 15-mH coil in series?6p6i pv d ny36y:hfg5u

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is needed in series with a 4.7-mF capacitor for a resonant 0 7poyixhdl+.yb w55xha4(pvfl10b u frequency of 10 kHz?a5vhw. b0lfdpxi17h l5xop (yy+ 4bu0

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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 inductor for a resonanj-nnp,0 gt;dhhrn4 b0 t freque -hpd4g ;bj0r0,tnnn hncy 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 resisgaf w*3*s)yuutor and a 40-mH coil fgy)u 3*su*wa if the resonant frequency of the circuit is to be 1000 Hz?

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