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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: 游客未登录  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 eiduje1u3 sfl7 v3 .0rtxcept

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction states tes+a28gnu3m *ve 9se( w-uicehat 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 wh b*v7*akv be3biiew96l,v( ajat kind of change on the induced j9i6(a*,7bb ev3w lbv kaiv* e$emf$, 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 uh:y5*qej s*do13luji,mjp :e5 ;beywire produces what kind of change on the induceduj,3;5*up hd1s q:o ile5b: yejy*ejm $emf$, 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 c 5b9 vbgti:l; l/ ,p3,zinzjbthange on the induced v l b;pi,l3bt t :5nbz/i,9zgj$emf$, 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 fk,:yq( scxrco +r nvz: 4rpl+1kmk.t/gu1 pq1rom 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 direct jb ,0bh rbfec9y/c(d1ion of an induced current in a conductor will be that which tends to produce which of 9j ,cybbbr( hc/fd01ethe 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 tb60a z 4yj, whbvgi-3magnet is held above its center with its north pole point-a vgb 04,6wtiz3bhj ying 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 bz)yeu l3 3;zlbar magnet is held above its center with its north pole pointing down, any3b )luz;le3 zd 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 fi5qt7wci +*xikeld vector points straiixk5+ti q*w7c ght up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top +w x) )qjhjir5eiq9x:nhp/h +in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the induced current in this coil asqqpe+r9ix /x+h 5) :wihn)hjj 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 rvy* y2-v fv*xpv 48oal0rv ;mhorizontal table top in a region where the magnetic field points straight down. The mvvvflv2yr mr ;*v0* xypo8a-4agnetic 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 27xc4u tbg.b+9iwq-m eb i; rgtt4fy6on a horizontal table 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 abox+i gyutf2 m.;be w4qr76tb 9-cbti 4gve, 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 througla2avh.2 2hxrh a loop of wire with the north pole entering first. As the north pole enters the wire, the induced current wi22hhr2a vxl a.ll 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 constant64 pqrl*6* wazmhz .o6koihz2 angular speed about an axis whose direction can be varie6zk4m2 lor z*hwz6 p6qhio*.a d. In a region where a uniform magnetic field points 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 constant angular speed about af..s mh txpj5qiih(,,n axis whose direction can be varied. In a region where a uniform magneti5m.hjx .,i( sih qpft,c field points straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be a maximum?

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17#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Faraday's law.e(m:q*bgs /.e;n mvsj
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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 6(tl 5. zqqg1h*tvf/ f6bi -g+ujkroi$emf$ 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 fiel96gc hjl2c xx0d. 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 morf fui3*k un06ved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potential induce0r *f3if6nu kud across the rod.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar rotates at a constant angular ve67 l5/ w/ap e1xzty-iejo(,i6bolpmvlocity $\omega$ 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 b7y cuq9;xewb5(.i.k* rx sjz 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 rey-*-mhjk se2svolutions each second. The frequency of th*jm2ss e h-k-ye $emf$ 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 uslu avs ;3( pyc+k,4nqded 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 xpxn).): e0l oissb d9that

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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 settz /2l;k)y lycondary coil contains more loops than the primary coil then it )ytzy /llkt2;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 more loops than the secondary ( u0ox4 2kwtkyuqe .5icoil then it is yt42uoi5kkeq0 x.(wu 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 /ay0dvx y*qf-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 resonantpkqxl8, (9 8h m whgrf6fv8g5v 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 cc3*p b)hncb v,onnected in series to an ideal battery of constant terminal voltage. ,bp)*3cbh cnv At 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+8e p(cvio,h:8 qdbrp are connected in series to an ideal battery of constant terminal voltage. At the momv+pce 8 ( p8,dqbo:rihent 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 -9zqel w hdb a*/:pl)bz c-;utand 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 resistance R is connected to a0gi7 2zj zf;ghn $emf$. 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 serieg:;-k yfc -erg 6my;qds to a battery. The time constant for the circuit represents the time required fo6fcgk-g ;y q; :r-eymdr 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 iuzz5-:choc3 / kp eefaw ie/a06;yre0n series to a battery. The battery is suddenly removed from the circuit. The time constant for of 5/wz6ieo0c/0:r- aeyapkze ;cu eh 3fthe 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 sam)aqo ti50 ex(se 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 circuit, t jz/ vt .qiyi- hw. q(zc-z)ukz(ua;u-he 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 circuit, t cqp)j/-tr.ww a3g7km.* i4 eh3jrlnkhe current3j wkwjpqak-me 7.t4gl* 3)h/r n.icr

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40#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The inductive reactance in an ac circuit changes by what factor when the fre96e 0haq8r7rifc5x/g 5 reiwfquency 0efrr/8i harg5q67 x9eficw 5 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 across an0thl wf)a3zy ; inductor is doubled, the inductive reactance o z;)a3 wly0fthf 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 approachescngs+.ssnvi.,g.1( ls0s cxx zero, the inductive re0gl.n xx csns 1s .ssv,+cg.(iactance of that coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In this circuit, the.u4 m(5tq*nro /ggxs6)ex wxc curren u5t xoq.6sx4*g/xegrm( )w cnt

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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 fr9+ok2a) jl jv omo1u5kequencom9 )o2jojv+1lka5kuy 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 zero, ./phmn5hm8r y( d5xbg;,uc qk the capacitive readqp;m n/ckrh.u5 g85m y(bh x,ctance 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 between the voltages of the inductor and capacitor x0v dpvvv;i :b)6dsodly, 8t- in a :-dyb0 d8 lvpidov t6s,v)xv;RLC series circuit?

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47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The power factor of an RLC circuit mgp(vh( ex q(a/.j emt/m,lck :l4bg6is 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 e;/, ys ds936asvbyv qincreases. When is thiabs /9s; 36y vyde,svqs 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 ichs ys(gh9 h.n)8j )trmpedance 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 1rbv0* qua8i2g 9ruynimpedance 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 doubleip )5dqpn7/n6k q5e oj in an LRC series circuit, the resonant frequency of that circui n5qpn/k7i)eqp5dj6 ot 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 reso zu24nww8py 9psgi6- bnance,

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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 occu k0vhwz0789 g +yeyvjsd9bq 9urs 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 f+*adq yt y(-9 lz+fohjtr)q -0.10 m is rotating 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 q9yr+)z th -j+-l of*dtyaf(qparallel.

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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 rxxqa/ do3r+c ( kjr3k-*z.qymadius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the rmqa*czd3kx3-ro(x/ +y.j qk 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 uniform790dclq n z0ez magnetic field of 0.20 T. Find the magnetic flux through the 0l97z0 dz nqecloop 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 adjh-*vz-i2;n t itdntz *ustable 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 coi20 8uwkvkf mv7l changes 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 turn d3(t 8qw kt*1itj,pfhs of wire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of p k3*,wifj1htd8 (tqtthe 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 *)yfrhl :ris615 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 areapb3s( r8g+nwh $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span of 60 m flies horizontally at a location where,o gkw3 ,b6cjmn0qozsh;6 0s c/x0 idz the downward component of the E0 m b3xc csh,dnjk;g/ z6i 6oqs,z00owarth'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 rotates at a constant an0tg jmkd6 rbgx5*uv98gular velocity of 2.0 b rjg0 8d5v9gtkxm6u *rad/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 has 50 loops and a cross-sectiog.,ebfgoa . y) n5;3iggzh0d rnal 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 100u.jsc- ou75; shw.v(tq.ts1py3psvx turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 rectangular loops on its armature. Eachc;vj h saq5h+* 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 maximumq;hhsavjc5+ * 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 pbhj. uwf:mse)h0 2( swire 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 wisq xwn )l 5/y70gj*d;7zptiot ih to construct a simple AC generator with an output of 12 V maximum when rotated z*)7nd0/5ytqgjpi7 x;tiolw 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 generlhv /u+13x1jgg0td ctator with a maximum $emf$ of 8.0 V. If the generator coil has 200 turns and a cross-sectional area of $0.030 \; m^{2}$, what would be the frequency of the generator in a magnetic field of 0.030 T?

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71#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have a resistance of 6.00 W. Te6f akvliz2k6try)*62jyy n , he 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 2hzs0*vv; tf y v9,mdl6.00 W. The motor operates on 120 V AC, and when running at fullsdv2,y9 h vl*0 tvm;zf 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 6.3*,;iwfe i)gdmu f4 bf0 W is connected to a 24-V power supply. The operating current is 1.0 A.,* gf4if) 3bm wuef;id 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 a 24-V powjo 3vx6 5-rnnrer supply. The opr3-n o6vn5xjr erating current is 1.0 A at full speed. What is the back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resisndnu dws9+xd x*/ i h:8eid1c7bm+bi-tance 6.0 W is connected to a 24-V power supply. The operating current is 1e9-dw /x78iddxihnin+*m1: cu+bbds .0 A at full speed. What is the back $emf$ when the motor is running at half speed?

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76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A step-down transformer is needed to reduce a xuhy2; /( wcth ( a tyaw/n3.5cs4efwqprimary 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 of a transformer causes 14 A to flots(( l: d miww5hkxvids(3w)d3/kep ;w in the secondary. How many turns are in tw ik3ikhs;epx ((5w wd :3dsmlt)d/v(he 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 primary if the 24-V zabcb3*j 3ko5 ;pdog7secondarb*7a j5zpg;b ok dco33y 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 l4nvd6qk 9kz .500-turn primary coil and a 2000-turn secondary coil. If the current in the se4lkv6nzkd. q9 condary is 3.0 A, what is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primary of a transformer. Assuming 100% efficiency ptobq)+(k/xds;a+ rurysin w4, ;qr0, how maqqyrxawtds r; pk/+( +rib4,); o 0nsuny amps at 24 V can flow 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 1r ovl 4:bt()+ogs2xzq 0.0 mA. The primary cb:rgt(+ 2lx) oz v4qsooil 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:8iyj7c 0 t vu4fcxxel183 zyt its primary coil and 300 turns on its secontfu3yz88xy i4:0vte c 17jcx ldary coil. If 120 V at 2.0 A is applied to the primary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coil and 300 turns on its c-aq6)t*)fo ere qkc61* jvnusecondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the secontf )ak)qcvn6o*6u*qr-e ej1cdary?

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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 200 turnc(ub (zi/yaa5k ad + 98gbgik8s. If the input current at the primar9/cdig+g(a(zi aky88bka ub 5y is 100 A, we can expect the output current at the secondary to be

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has 200 turns. Ik6) i 1 lnoonocwu:+d+f the input voltage t: u)+ +ow6in ln1odocko the primary is 100 V, we can expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 10w lb *hr+bfyh-*e:jy7 w2(mcx 0 turns and its secondary has 200 turns. If the power input to the primary is 100 W, we can expect the power output of the secondary to be (neglectin+7r*h by:-my j (*2xw cblefhwg 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 producesu1i twe v1s7,z 60 A of current at 120 V. The voltage is usually stepped up to 4500 V by a transformerzs1tiv1w ,e7u and transmitted through a power line of total resistance 1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usually stepped7z87adjqzuc8j y 9t(a up to 4500 V by a trans jzct7a(z 8u8y9aq7djformer and transmitted through a power line 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 6 qb;u(y.ldli A of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find thi;y b.6dq u(lle 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 resrts0 akgf /1;2 zmk(o;cb xr+uistance 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 steppedkbmt1 krr0+c (u/o;axs zg; f2 up with a transformer with a turns ratio of 100:1. What percentage of the original energy would be lost if the transformer were not used?

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91#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a total resisz)wo uokfz9yv( yb 43)tance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due t ybo(uz) yv4o9wf)z k3o 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 lmaom7v61ks8f8 :says ;7p8+n suik i line at 1000 V. How much less power would be lost if the power were transmitted at 3000 V insteals8m;iy8usosi1 6n87 v+ k7 :aasmpfkd 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 V5fo5snr.mq sj-b9w 6 mzeqakdp6 344gf( jf /q at 20 A. It 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 the power loss in transmission is not to exceed 0.010% of the orafm4 qmd6psjb4/fnq65 (3o f .e zw 9q5r-sjkgiginal 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 eo/ pd3gn wt. m+waobul7;).jxnergy is stored in the coil's magnetic fie n7wgux+wl po/.od;aj3.tmb)ld?

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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 dv g ;rl(x- xo9r:et9can 18-H inductor. What is this circuit's time constant?rev;(c:rg xl -xt do99

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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 circu mgr:-39zs-vuns i(w hs /4lhdit 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 is the peak current;e,te1ifa7r05, i4 uac ayvh1p/ d vle?

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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. Wh4ys y6t a bifl9zq/r96at is the resistance of the lampra izsq69ty 946 /lyfb?

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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 pu7 il)hvwema ;: j*ggwwgag9n5ue38 9ower supply. What is the peak current through the resistor g5:l vheg;3wmnaiu uj9gew*g8a)7w9 ?

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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 q /(jdp)jcwo 7p,0uyc a 120-V ac power supply. What is the power dissipated iy)/c pdqop,07juj(c w n 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 resistor is 0j e e2/uo9typt6b o:a$I = 0.80 \sin (240 t)$. 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 resistu as5 8uz7ms dscpvl9nehl(q1*:z8r 5or 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 resis5 8bnd,s:hf4cqc*8txy e:wj u tor 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 at 60 Hcr (e2n jo.uuwn0e +0iz?

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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 rh5coyqq1b-8j eactance of a 2.50-mH coil at 1000 Hz?

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106#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will a 14.0-m;v(ku3 d ;; pzbyr33knbfm5i zH coil have 14.0 W of inductive reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 157 W of inducti7:t t6keb vl *y+jj7ecve 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 kHzy z b z/cvmob*x 9v*+1ox-g 5myp/h7cj isb9gzxvvyj5pch/mmo*coz b*y/ +x 7 - 1 applied 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 t -t5-wmi1cl ggo )ch5lhrough a 2.50-mH coil due to a 110-V, 60.0 Hz source?

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110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitive reactanck u x+c(qd ;4u4u xjvr:96wf1rpgx sy.e of a 4.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is needed to have 50 W of capacy)qb,fwkg( iy6luf .2itive reactance at 10 kHz?

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112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacitor havekl5 qqec l-89h a reactance of 1200 W?

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113#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will the capacitive reactance 9d j* abvx5-)/ k(st2dxh yhcaof a 0.010-mF capacitor be 100 W?ach( )9x5dbjsa- k/x v2th* yd

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114#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 0.0010-mF capacitor at ikig wt:ug) 2aa(p) :*fa7yfy1000 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 cir1 x;y6n(aulry;ohc3 scuit with 12.0 W resistance, 15.0 W inductive react;su6 1c3rxlh( onyy; aance, 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 150 3uu1qd 4sknu-0 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in ser4suu13- qu nkdies?

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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 157mb cr s14 puok)b; nt3:o0vdf00 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in series?k1v;b7oodm) 3nb:r f s u4c0pt

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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 connecajm 2e/wv+(tzh , jfq3ted in series with a 20-mH inductor, what is the impedance at 10e2 (wj, 3vh+ tzjfqam/00 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 withcvpj6 6xkb.+z a 20-mH inductor, what is the phase anglbk6jxc+ .6zpve 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 neef o(m 00lmf/h(soxau8 jo w/:sded in a series circuit with a 20-mH coil and 1.0-mF capacitor for a total ima:h o0(/usfsoo( xml08j /f wmpedance 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 capacitanceno (4a*g4 r 6ossf/kxis is needed in series with a 100-W resistor and 15-mH coi( r/iok*f 4ogx64sns al to get a total impedance of 110 W at 2000 Hz?

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122#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance must be put in series with a 450-mH inductor at 5y(/jwe*- mp5j5 mbl 2fi3 degn000 Hz for a total impedanc 52pedjm3 byjm in5w/(-*leg fe 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..0jl 6ljrj y5j vs -/sag2dd)c0-MHz for a tota 5/6jl jlyvd-sarjd0js . gc)2l 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 series wi +w,s::y pqg+k3gp haath a 20-mF capacitor. What is the impedance at 10py:sa gawp:h+q ,k3g+00 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/ )l lmsxefs+txg.d.zwh) l 23(fut )h at 1.0 kHz for a total impedance h/.sh)zt)xsum3fll+w e l2.xtd)gf(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 w,463topk s*ladgl ot4 ith a 10-mF capacitor at 1.0 kHz for a phase angl 4p o klosd3l,4tg*6tae 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 nee2*yen2 4 upw2ctf ba9xded in series with a 30-W resistor at 1.0 kHz for a total 42y2excb2uwp9a*nt f impedance 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. What is the ph/k e2s,xh)a1t9s1 yxw jq(ycqase w2q/cy1x(1ts9qyhj ) akx se,angle?

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129#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows at 5.0 z8xvjy4t y5a1cr)0+jgak d*kl/a*2d hck p7y V and 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in 7l5ja hyg 1kpxd aycz8*kjca)*+2dy4r0 /v tkseries?

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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, a 10.0-mF capacitok9f.oh v* g8zw9zb,dtv0s a 3sr, and a 0.350-H inductor. The circuit is connew f8azvhts. kz3s d9o0v,g*b9cted to a 120-V, 60-Hz power supply. What is the rms current in the circuit?

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131#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistance of 55 W, a capacitor of capacitive react5ihocgk k 57-hance 30 W, and an inductor of5ogki-c 5k 7hh 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 circuit contain wt-hxh*o, mgy8(ap6bing a 50-W resistor, a 10-mF capac *ta-hwphb86 , y(xogmitor, 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 resistor for a phase 38* amikh l93svsu.yzangle ofuzsl8 s*339 iyvmah. k $40^{\circ}$ 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 6( qsqr1z;vax2p cf3i= 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the circuiazs(;v6cx rq p1qf23it 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 in an ac series circuit with 12.0 W resistance,rpjb)1;b qo /zio43ppi 9;k zr 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power sup o4/;ppr;br39zj kpbioz1i)qply?

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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 /7ytu9fe/ i mwcircuit 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 and a resn5b ;pe mxj:,listance of 30 W. What is thepxne m,;:5jbl power factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series RLC circuit cont ey4gg 2.k*kfjaining a 50-W resistor, a 10-mF capacitor, and a 0.45-H indu.egfj2 yk*g4k ctor, when connected to a 60-Hz power supply?

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139#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the resonant frequency of a 1.0-mF capacitor and a 15-mHi7 u93y0ckcbo3.u y zt coil in series? iuo30c3t9kz7yyc u.b

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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 fv- rk;ek3 1;j) sgcnvsor a resonant frequ ;j;k1sv rsg3cn ke-)vency 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-mHwk45jf5b-faq9 nhl89 3 y6ewlt +vzj g inductor for a resonant frequency of 1000 Hzty9l8+hw 5v j-6 genb5jfflq394wkaz?

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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 serie4/b6 js9 i2uol8rcxxju0 x1yx s with a 30-W resistor and a 40-mH coil if the resonant frequency of the circuit is to be 100orjyxxi 9ux6b u1 c4 02x/8lsj0 Hz?

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