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



 作者: admin   总分: 142分  得分: _____________

答题人: 匿名未登录  开始时间: 22年08月20日 21:29  切换到: 整卷模式

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1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following are units of magnetic fxw*cw)-egbhu;eu x2jps5 /su *.uex o;7tu 6 hlux except

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction s d xx +nb nqcc3p(;+c.c,ev:hftates 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 whatzsdzh8;j (uvdvl8vca rj 2qu4:4t .f+ kind of change on the indu4j h :svau.z4qdrul+8t 2czfv v8(;djced $emf$, 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 throu/.x + o(4s.yj q0s4fvthykfnfgh a loop of wire produces what kind of change on .jnsqsh 4t/oxv0kf+yy . 4ff(the induced $emf$, assuming all other factors remain constant?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the diameter of a loop of wire produces what kind ov f;wieh:l.,, iu var6f change on the induriew ,al.vf h uv,6i:;ced $emf$, assuming all other factors remain constant?

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6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As a coil is removed from a magnetic fiel1k3:kab e h e 2+epkhpbd.b75wd 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 current in a conductor vik t;1 0 l*pzou:h)angbkv78 will be that which tends to produce which of the followin;7 u zv):polhaktgkvi081*bng 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 barwbv fds(z8v)cr97vv - magnet is held above its center with its north polsvr wvd9 z7vv (8)-fbce pointing down. The stationary magnet induces (when viewed from above)

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A b f5) ehc :udv2ax-:u roqsd0d+ar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magne:)u+d5ud:roscfd - v2qa0 x eht 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 magnu.;plmy*go +cetic field vector points straight up. The magnetic field vanishes suddenly. When +.gocu;lp*my 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 in a region where the magne uw 1di /qyku zk*ai/--fnuo9vtc.:; rtic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the induced current9ouci fn-qd wuv k/z.:u1ar; /k*-yit 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 n5 pw/8uy 9wjjhorizontal table top in a region where the magnetic field points straight u n9pj5wj/y 8wdown. The magnetic 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 on7o; x urs9gf.sk jd3 1xw.osw( a horizontal table and carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either side o.wj1.gufx7 kors wsxs 9 (od;3f 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 north pole entering first. Aela*h huf34v, s the north pole enters the wire, the induced current will be (as viewed frome vlf*,a4uh 3h above)

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angular speed about an axid gp4q7efw /.ds whose direction can be dp ./ wef7q4gdvaried. 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 constanta:f6 1s4kzdgz;0 arms 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 sga fr;z6 sam :4d0zk1of 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.) ga-0sv7 lsrn
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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 ojmlw0.:r1 c*qvbb lb-gj10 n an $emf$ can be induced in a loop of wire.
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20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A wire moves across a magnetic field. Thog8j dkqae5 /2dy,( m0w.qs s t1ghfy7e $emf$ 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 at con-boqye6.b*su stant velocity through a magnetic field that points str6*eyb ubo -sq.aight down. Make a statement concerning the potential induced across the rod.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar rotates at a csa . ujzc:hdg7-yn3l2onstant 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 tz: ujt8qt/u4 nransforms

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24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator coil rotates through 60 revolutions each second. The frequency of t mw)a,3aww 0w*ygh2llux1b *ghww)m1 awu 0 g*xh2bawy3,gll *e $emf$ 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 48+csy mjtx 0bused 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 devi6+hq 4 q3dnzqfce that

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27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the skqux 8w(;u1vr econdary coil contains more loops than the primary coil then i1qkuux w8( v;rt 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 themx71 99s j,m q.gsedbw secondary coil mx sed9 7wb1msq.,j g9then 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 inpum;32fa9lw 9 e cu0cdnst

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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 circui5+k d(jix7qr qt,

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to an ideal ba /l:oel i9)ilpttery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the re9:i ple ol)i/lsistor 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 conz;jb zxolh,*r tx 3o 1r5)djg3nected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across tz ,*xrx15j3 z;oo rh dbj3)tlghe 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 inducta-dolsl -w.lf w 2q/ve6nce 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 en6t p+e.5alawith inductance L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a battery. The time c,dv p4zyq (af way)v7ln11aa,onstant for the circuitfv ( 4d,l v1)qzaa1apyy,wn7a 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 in series to a batqvly0ohebcx8wxw(54k 9:g q( tery. The battery is suddenly removed from the circuit. The ti(8wvqxe0w:b4 kxc 9l hqo y(g5me 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 haoqpa*w2 j,/2fqmymn f k-3(hbve the same 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 rdw; lgd+;vt0power supply. On this circuit, the current

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure inductor is connected to an AC power suppl 9igre58ak3 pyy(un;cy. In this circuit, the currenk3 (euracn i;59p y8ygt

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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 nntu n1vi9-hf..6( b9xrwuhd tc)1f p ac circuit changes by what factor when the frequencnirh6)f1h(d9u t f.wtbcvn u9.nx-1p y 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 abzp,1 cxa fgk3: vk3dk7ea-9o n inductor is doubled, the inductive reactance of tha3e, 1zokpv g:kx3fdb aac79 k-t 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 c:t2l ui:yyj3pe) (ex4cf5osinductor approaches zero, the inductive reactancu4:cecx3 eisj :yt oyl) f(p52e 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 supplf187n 0zrhun7 vmo5mry. In this circuit, the currentfv0 rh ur178o7n mmn5z

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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 whfhoa 739ieh/ tp6gkxq( q0k8 ien the frequency isq hfgqkt9kh a e(o03/67i p8xi 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 across9rrcg;y v/rkbr) t.l5 a capacitor approaches zero, the capacitive reactance of th y t9gc/ rkr)r;.rbl5vat 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 ru qijynh01pyx)v 6 0;;j j9ahbetween the voltages of the inductor and capacitor in a RLC serihy6j;r)h iq0j ;a9yvn1 upj0xes circuit?

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47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The power factor of an RLC circuit is defined as +nbxrg;6aq vwf(n7: ; cf q)9ltz3cz b$\cos M = R/Z$, 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 cz ;-1vyvfrb( xircuit increases if R increases. When is this statement-yz1v( ;vbrfx true?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the circuit inc.e,qxn7 5wt jb c gek2vi-++atp 21wvbreases 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 trpbun2/ 2sp7 1+k fgzyhe 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 bo+3d os2m6ojsxx*1b ki th double in an LRC series circuit, the resonant frequency of that circ3k+o1 sdm2jos6x*bi x uit 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 circijiwn/ 9 *ol4t,hwtr7uit that is driven by an AC applied voltage. At resonance,

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Resonance in a series RLC circuit occurs wzetqk tq/h58( hen

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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 mh 4yofr(7 oy1-k dvs(s is rotating in a uniform magnetic field of 0.20 T. sod7 rf (y-1sv(yoh4k Find the magnetic flux 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 uniform magnp+ 5sj3 jk7z (+yuqlxxetic field of 0.20 T. Find the magnetic flux through thexq s+ulxp7 zj+yk53( j 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 radiunvhckm e8 +4u8cc xa03s 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 vectm4u 0nc8c ha k3xcve8+or 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 ofo sl j -onx1*6bxq2g+e:qwut5 an adjustable single loop is reduced from $1.0 \; m^{2}$ to $0.50 \; m^{2}$ in 0.10
s. What is the average $emf$ that is induced in this coil if it is in a region where B = 2.0 T upward, and the coil's plane is perpendicular to B?

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59#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The flux through a coil c(:pes /g o(brihanges 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 wd 6cqo*7jf hmu:)ns 0hak3gr;ire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular tnrh7 6aj 3m0*qgfkhcsudo ;): o 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 area of kof,u5 7l;i8l r0v j-vvy 3wdc$0.40 \; m^{2}$ 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 area ;wypsglq.q0k 2fnb :hxgic f;49a+ b3$0.20 \; m^{2}$ 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 theo/h 2rvr-s-q m up0vv1 downward component o-q/0vp-v r srh1umv2 of the Earth'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 angular velo:jqnws(m s9z;vkl3 0pcity of 2.0 rad/s about a vertical axis through one of its ends while in a constant magnezvjm l9:pq 3;w(ss kn0tic 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 50l75zi0v1: (odsybot c 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 consig 6qto4r 9hjx l*df*9*j )ztjbsts 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 $emf$.

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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 armatureqz )d*yq, *waq7m6jfi6uv s z3. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, whis*y)qmzv6,q*fi7z6wqdj 3u a ch 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 w425;j*;wumn5hwo ct u oahwb6 ire 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-xxw 18zayl( r with an output of 12 V maximum when ( -xlwxa18y rzrotated 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 ma:6cu4 wr;p2 pre b0fqmximum $emf$ 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 mo,ldkpw1 oz.c:g36 qb9wx7iqp tor have a resistance 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 resistance of 6.00 W. The motor operates ong1cg hwry35)jm)sd5;mct,.;ajmk g v 120 V AC, and when running at fujagr;5jct m sd; , m35)kghcg)m.1vywll 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,.agiu4pbnn 28 7 bsrh W is connected to a 24-V power supply. The operab,h82rsi nb .ng7ua4pting current is 1.0 A. 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 power supplw jmghp(a5 56qy. The operating current is 1.0 A at full speed. Wha qpjga( 5h5w6mt 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 connectj *md*g t q6,ct0z8eoio( 8abred to a 24-V power supply. The operating current is 8(mz 0idc 86*ojte,agb qto *r1.0 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 transforme)jqp ;;keuu/ b :o8uqfr is needed to reduce a primary 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 flow in the secon-c2 94tn*jzx6(fm pfz;pd onfdary. How many turns are in the dz4p2f tz f 9p6-xj(f;n*nmocsecondary?

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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 primaro: aj;f/imu xt5 +-iuzy if the 24-V secondu+tj xaiuf/ ;z:- om5iary has 100 turns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consists of a 500-turn primar.sr lm-1us)dt ap; /rwy coil and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what is the current in/a .)msrtp;d -uwsr1l 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. Asaf9-au;fy ( unsuming 100% efficiency, how many amps at 24 V can flow in th(f-y aua9nfu; e 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 trn6a.) sq srgs3ansformer provides 7500 V at 10.0 mA. The primary coil operates on 120)ss6nr g3.aq s 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 308 a tkrm :zikcs.w3qvk7al);;0 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary;a;:t7m clkkik 8v.rz )qsa3 w, 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 secb*3*e3y* c frod-pyzlondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the sec cr*zflde*-p3 byyo3*ondary?

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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 tuv oo-ysdy)0 6 ecnvjhb8;k:6 jrns. If the input current at the primary is 100 A, we can expect the output curr6 ceyo 0;8:hnkv)6jo yj-vdbsent 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.cvipj4 to- yxxl3m)c x6u.m:- If the input voltage to the primary is 100 V, we can expect the output voltage of the secondary to be -j.c3t6ilxm -m uoxvpy)x:4c

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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. yo: iwj3/ yiy+bdo- loj2rl:bu 3l+5r If the power input to the primary is 100 W, we can expect the power output of the second-lrjyyoiw3+b/rj: b +oi 3 2l ydol5u:ary 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 curre1 mdfmvbq8xv6zw j hxi5/x/-2 nt at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total6vm81d /xz x2qi-xhj wbm/5 fv 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 Al u1pp6-c5eiw of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and trans1p- luie6w5cp mitted 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 A of current ar./ valb ,hyp;t 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of to,a;b. /hl vyrptal resistance 1.0 W. Find the percentage power lost in the transmission line if the voltage is not stepped up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a total resistance of 0c va4-dyw +*f;hk6jgadjj 79az j2q3c .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 transformavjf+ gh7a jz39ya;c2*j4dkq6wc- jder 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 totp ix r )ixaig48lp151cal resistance of 0.60 W. A generator produces 100 V at 70 A. In olcx1ia8)p p1i ir x4g5rder to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W likpcy4pt2r5y: .vsf n/ne at 1000 V. How much less power would be lost if the power were transmitted at 3000 V instead of asnkp2 :yvf.cyt5r4 /p t 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 jeh(azyjpq.,0wbs7u: j*z* t 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 excejp w0,7 e *:j.h *bjzt(uaqsyzed 0.010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. How much energy is stored in the c v1atoa8fd- m2oil's motdv1a8 a f2m-agnetic 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 in1l3; z5uetsmgductor. What is this circuit's time conuzs1 met3g l5;stant?

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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 naj-;cv+ ngy)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. Wvkw zc )u-lxqr2y :+f9hat is the peak current?

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98#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC/)ugeh z0s )aq outlet. What is the resistance of the lamp0g es/zhuq )a)?

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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)7aljk;1v vd r supply. What is the peak current through the resist 1vk)ravl 7jd;or?

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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 con ewn(pxwu q2ygc3nb7./a ++ee nected to a 120-V ac power supply. What is the power dissipated in the resistor/c+ n3 7.y2eugw+(eenq bwxap ?

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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 resis+sf,u f:s9zin,/x dffsl8s1ntor 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-Wlepf,; vz 7rp 535kyte resistor 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 resistor isl 5o-qq5fce6(b8 3xzko:iqfq .k:b w-t,scug $I = 0.80 \sin (240 t)$. 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 6eqwn *8 ;hs2hw0 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 reactancg48n)rp rdm,yk f; -4 aczsi1de 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-mH coil have 14.0 W of ind ve g(-fjnh rc)zn58+k2cta 4nm ;l-kiuctive 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 ooq zr,,)rs7c7xi 8io; xf4a mif inductive reactance at 1000 Hz?

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108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH induct. 3w*q* quw x,p,9rxe ,7fzsy-ymwdfuor when 120 V AC at a frequency of 20 kHz is applied to, yzp.* fmw- s9x,fqw ,*7euq3dywu xr 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 t7;-:2t vyoq*kzk mcgc hrough 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 reactance of a 4.7-mF capacito7c coalec6:j ,r 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 capaciti0v6cb h3l b5cn04bax pve 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 have 38iry*a8ci arqq i:j+h6z5 tya 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 wilaj,e d; yi,5. ecsknd5l the capacitive reactance of a 0.010-mF capacitor be 100 W,n e5 j;,kdye dcasi5.?

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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 0.001cl73vfjgt2 rfjb 3e ad69d *5nd -ds;w0-mF 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 1(qf3iagtq2jdp3 0lgresistance, 15.0 W inductive reactance, and 10.0 W capacitive reactp g( gd1qlt33jiq 2af0ance?

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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 co ih3cs :grk2p0il, and 1.0-mFh0cgp2i 3:kr s capacitor 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 atn .(ku o;u+eec 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connecko( c+eun.;ueted 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 zff06 5 pgvy+eis connected in series with a 20-mH inductor, what is the impedance at 1000 Hz?6e zy0+gfpfv5

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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 conneclduj js1a v7:i9,c 5ymted in series with a 20-mH inductor, what is the phase angle at 1000 Hmsicva,j1jy7 59 l: duz?

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120#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in a series circuit with a 20-m51t/ue6dyd/ p r1hl 6qkz3hlkl vso:*H coil and 1.0-mF capacitor for a total impedance of 100 W at:vd*l/6o k1 zr13u6delq p/h hksy tl5 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 capacitancesr ( 0i8vvloka c7t-o4o is needed in series with a 100-W resistor and 15-mH coil to get a total impedance tci ( o0kovr8al4-o v7of 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 45uqyv t6gbv : o6a36+ra0-mH inductor at 5000 Hz for a total otuqa366 a:+yv vb 6rgimpedance 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 resisto c3y-k kfuu(lz9u*u 8cr at 1.0-MHz for a total impedancyzu-(c9 38 luu f*kukce 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 +e uumx jxd.nk:6,:c ja 20-mF capacitor. What is the impedance at 1000 Hx .u:d +nckje6m:uj,xz?

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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 fwby:3v wpth3(ke 12b10-mF capacitor at 1.0 kHz for a total i(3: v1y 23phbwk efwtbmpedance 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 neede0d ybt(jvcl6u w9a1.j d in series with a 10-mF capacitor at 1.0 kHz for a phase angle ot( bw1lad9j0 v.cu6 yjf $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor alegpapu3qw6gu-w j12 ( : jhw6t 1.0 kHz for a total impedance o-w u:wpp1(w 6g gehl 62jaujq3f 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 Hzuh w d05s .9 9 x/dnq1aytvi:ev-iua.v. What is the phase angle5 a:u/ yt0hvv9ai-qnxvd iu91se.d. w?

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129#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows at 5.0 V and 1500 Hz if a 100-W resistor, 20-mH cch20jrmxg* . c( r4eosoil, and 1.0-mF capacitor are connected in series?0r. g2je h*scx4 omcr(

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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 -tnxscu e 3- 8krtnr:sjj161tof a 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power supply. What is the rms cur -rusntnscttk jx16e:8-r1j3rent 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,e-7wvmz x+;s l a capacitor of capacitive reactance 30 W, and an inductor of inductive reactance -m+ vzwelx 7;s30 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 containing a 50-W resistorb-/ guuuo-bof h;5b1 (h 0uzca, a 10-mF capacitor, and a 0.45-H inductor, when connectef/u5b hb;ugc--oo 0b ua(h 1uzd 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 seriz+m :cl6n*zv43 oni3+q iyxzklq/im3 es with a 500-W resistor for a phase angle o lli*i3q 4mz:++n x/i3mynz6k3cqvz of $40^{\circ}$ 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 /s;vi t 9gia2ihas R = 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 driving sourc2 avis t;/9igie?

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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 circuveul: a6 nrlvvu*.y.,9w0e huit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit isrey6n* uw.al.uv 9:0ehlv,uv 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 an6l(t:k 7c pfel 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 60 W and a resistance o k9s:z ;jjagg w75q3kib.pn+v f 30 W. What is the poww;7 :si vj. kg95b3n +gaqjkzper 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 factoquapz8,b d r47r for a series RLC circuit containing a 50-W resistor, a 10-mF r87b4 pqadu,zcapacitor, and a 0.45-H inductor, 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 capacitz*qv5g( 8fi,mti2dt zor and a 15-mH coil in series?5, dtmif(2qg8 ztiv* z

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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 h/eyr9(v nuj6.7-mF capacitor for a resonant frequency ory/u6j9 (vnh ef 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 wo+ fc1)0ozmf fith a 3.7-mH inductor for a resonant frequency of0f)fm o c+1ozf 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,lg 1o r(km3 suk3gx+w8- pxwq 30-W resistor and a 40-mH coil if the resonant frequency of the circuo-q 3gx(wmlk1pks,w 8 3 r+guxit is to be 1000 Hz?

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