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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 mag,t pvri d8y6v)s95x 1kohg3ctnetic 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 inductis8dp.1.y 2mk y(a nsrion states that the $emf$ induced in a loop of wire is proportional to

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3#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the number of loops of wire t .vk;dw 8/zy9fc s0goin a coil produces what kind of change on the tv0s9 w .ofzkc /g8yd;induced $emf$, assuming all other factors remain constant?

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4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the strength of the 8:5r*6xsf d 2 vvwfpc.di0zlxmagnetic field through a loop of wire produces what 6xdf vv l*8psxfidrz:0c25w. kind of 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 produces what kind of cha d,cv1d5j4q 1g x y-rfl6r,gvinge on the induced f, ix cygjd 1qd,g rr4v6vl5-1$emf$, 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 p6kb im kxd:veh )b05.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 current in a conducto-atp.- hcj zbe9el)m ye.mz ;8r will be that which tends to produce which of t -j a.8hplybmze.9tmzee ); c-he 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 pz/ kuxiv*cl 2 p/1hj4horizontal table. A bar magnet is held above its center with its north pole pointing down. The stationary magnet induces (when vil p/1ihvxcu*pk/2 j4z ewed 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 tabl+tpmwbr;v1xl61 zb -ne. A bar magnet is held above its center with its north pole pointing do l11wt -vx;nb6r+pmbzwn, 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 vti0h7ex ba 9x*ector points straight up. The magnetic fiel9 7t0hexaxib *d 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 in a region where the magnetic fissaf: e+ hkbmj-sf +hh4 44-roeld vector points straight up. The magnet -+eh4h+jb:s m-ao fskr44 shfic field suddenly grows stronger. When viewed from above, what is the direction of the induced current in this coil as the field increases?

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12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a horizontal table top in a region where the magne(-bma8nao*2yc -vuw utic field points straight down. The magnetic field disappears suddenly. When vieaa n u-b*(u2o-c8myvw wed from above, what is the direction of the induced current in this coil as the field disappears?

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A long straight wire lies on a horizontal table and carries an ever-inkmdqng6 h )x:-creasing current northward. Two coils of wire lie flat on the table, one on either side of the wire: n-h 6)mgqkdx. 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 poutd,h2 ms-)f cqe z3n)le entering first. As the north pole enters the wire, the induced c)2 fqhucd3 m-) stnz,eurrent will be (as viewed from above)

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angular speed abou e+yo+afg e7ztcdml,-p 8. nh xph/8d5t an axis whose direction can be varied. In a region where a uniform magnetic f apdh7o8 l+yh5e-czemg.xd / +t8p,nfield 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 abml.dmv9z4:.apvb ra8 5d9l0;pqrto n axis whose diq d0p9;9l t:lm.m8.4azpbvd ro 5arvb rection 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 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.rt qcke.f73 14o/tpugdf7;av
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18#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Lenz's law.
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19#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
List the three ways that a q : rp05, e49r(bpg aiwty2wkclt9n.qn $emf$ 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. Topr:xiw ub 8+/he $emf$ 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 ts1;uqe zpzn21fg* sj 8yw -x2bsc(c 0xhe east-west direction) is moved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the pc-y*z1qxw2s80ns;2 zsec1 gbpx uf(jotential 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 con-fo/tb m4h.tksh gku4 hx35 +ostant 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 d5 ey ddscz, 9:m2f0( kegpd9ytransforms

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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 thrdft43xiulh 4;.y 5x mdough 60 revolutions each second. The frequency of the d.f5u ;dx3 4l yhmt4xi$emf$ 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 up- 2gt4 i0qmzyx;ydx 0zl95s 5n)iiiosed 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 devff-q:v v ,ug)dv)7 mzdice 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 secondary coil contains more loops than the primary cddf idcvdl9 a;4:1y 8voil thedla;: y4 9 1fddcvdi8vn it is a

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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the primary coil contains more loops than the seconav2ntck c8c; k 2nyq92dary coil then it in2;vn2a qckc k92yc 8ts 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 g)y1zb1sk2,r )bgamo7k; s zt power 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 resonan qcudwtv1gx)8 mvfs(10)j 8h,xpv dvq,0 jr2et 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 conneci2qtdsujks/k m-sz4z ah/d6 q4w) * )eted in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the volskkq4dz4 wa6z)*jht/ s -mei/ 2u)qsd tage 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 tovqhqx,g.t y +0 an ideal battery of constant terminal voltage. At the+,qh v .yxgq0t moment contact is made with the battery, the voltage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance j:;49mook)i6oe orai 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 inductancea rgdcd):, n6n 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. 9i/ gf;zveip;3flk3,u 2ye fv The time constant for the circuit represents the time required for the current to reachuif/p;9 e23zkf3lgf ,yve v ;i

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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 batter,*nh zdoie2zda:d 6-dwjo.c4 y. The battery is suddenly removed 2zd* oh:-n,ddcdo eaiw4j.6 zfrom the circuit. The time constant for of the circuit represents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the ; 6q*en9 emltvsame 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, tm,uf3e axlw-ncsi7.0 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 cobu,dc. -; rvdynnected to an AC power supply. In this circuit, the currentud, rb.d -;yvc

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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 frivmue .9:db y5equency is tripled?.u :i5 9eybmvd

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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 ,h- t j9h2h(kr;+jiweujt;v xacross an inductor is doubled, the inductive reactance of that inj9 +jkh etu2;; wv(r,-hjihtxductor

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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 inductocbqe; bx8-3yi i so(uz)w0:d tr approaches zero, the inductive reactance of that cosqxtzw i3b c) d;-0:(ou 8bieyil

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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 coq tf3fserivh ;wju+t58,:8 hb nnected to an AC power supply. In this circuit, the current uhqf, 3ibw;hevfjrs+8 t:85t

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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 chif mvrou+43mzfpgmy0j- kt4-u3 3q - janges by what factor when the frequency is triplj4uyvi- z3o0k -gr f-pmt+34u jqmm3fed?

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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, the cap-9z*i.drux )xhp k;wxacitive reactance of that zwx-ix9p) dr x;h. uk*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 theltmf(sd2e(wj + /g /0kh)crhfb /v ox. inductor and capacitor in a RLC se(hs/c.)kv+2 j(fm tw0rg/obe dhfl/ xries 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 r 2kaot8kgbl25hlybmh+ d07 8defined 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 ifb a2rq(g+i2 dm R increases. When is this stab+r id2gm 2qa(tement 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. Thewaxvpl7qaz9 3 m34* mq impedance 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 circuit increhm 02pj8d -aiqases 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 anepvp d;nz 2.x:vh)nj+d the capacitance both double in an LRC series circuit, the resonant freqpvv.;p :)dzenhn2 j+x uency of that circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is driven byt3(qsg8 b8br f 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 cirepogo /+di o1hoj n )bv-1p.d5 vmhl.5cuit 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 field of c 6/0vew u,v v0mdg9lh0.20 T. Find the magnetic flux through the loop when the plane of the loop and thewcm6dglv ue0vv 0h9,/ 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 7d hcfv8l6opt v+7a4trotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop anddhat7vtv8c4+p7l f 6o 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 unif p:j y-,uakwm0 o4xc0ka* k+hnorm magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vec4ymwh*a p0- ck jao 0uk:,knx+tor are at an angle of $30^{\circ}$.

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional area of an adjustable single loop is reduced fromu:befhy 8e z8 z:pm.g/ $1.0 \; m^{2}$ 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 changesqm9u/)6d ,4t q dcelty from $4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a square frame with 0/b o( cg6ax35eig jv g5i/tetsides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field cha tjbgo5ge036gti iv5(ex / a/cnges 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 oxrf+: cwlr: 4sf $0.40 \; m^{2}$ 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 ar ntsmc(6/n( ij j)7,1jspv;46d, bk owtfyg ssea $0.20 \; m^{2}$ 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. o, 5g itcze3v 2(ygdjjav60v horizontally at a location where the j2ozadvt3g, egv .6(c0j 5viydownward component 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 rotate x b(-xk0js5(/sn anias at a constant angular velocity of 2.0xs5n(inx bks-a a0/j ( 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-sectional areao82i; xlcb,sh 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 o8s+:fwq hn,izf 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 1h9xm7h9rctz rectangular loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular to the axis of ro9mh cxztr1 h97tation, 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 ock, sa9y- *fre due6*x r;ou)cf 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 sihw/n(p;-a1t rrok z1s0c. xwymple AC generator with an output of 12 V maximum when rotated at 60 Hz. A ma0a or1p(hx1t -y/ z;r.wkcnw sgnetic 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 gcqt-i um,4otnko8 )w6enerator 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 resistal gemvgr0bx+hi64) x/nce 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 hapvzi (,o6(;k ov5qz(lhnpk q (ve a resistance of 6.00 W. The motor operates on 120 V AC, and when running at full speed it gev;(( plzk(v hk5q,oqizpon6 (nerates 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 connectwk y1a4w m9y/daoth. -ed to a 24-V power supply. The opermwk1.4wd /-a ytoh9ya ating 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 resiso 6udg)kl br4 *, ox9qjqfr*0wtance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A at full sp4 9qugr)klojw,d*q6b 0rfox *eed. What is the back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected h*( ude79;-j+ o73weodtm bs2 xcr ytpto a 24-V power supply. The operating current is 1.0 A at full sp( xj9tmohwp7*b+dre yd -tce 27;so3u eed. 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 primwij) juoc,6 -kary 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 s qk,++ mpuv; +8lmn3ybrfm0wa transformer causes 14 A to flow in the secondary. How many turns are in the secofw qnbl0um3+ m+ k; vmp+8,sryndary?

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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 ++i u/acp s-xkw)pi :rare necessary in a 110-V primary if the 24-V secondary has 100 turns? r -+u)a+:xc iisk/wpp

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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-turnf9 okg a*hlf49 primary coil and a 2000-turn secondary coil. If the current in the secondary is 3.0agl4 k9of*9hf 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 tb 2jeyuh+z* :zhe primary of a transformer. Assuming 100% efficiency, how many amps at 24 V czzhb2ue +: *jyan 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 10.0 mA. Thed) zsz*eguvt83+yr e , primary coil operates on 120 V. Wgze d8rv e*u,t)+s 3zyhat 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(ntw0m2h (yca 60 turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0y(w0( t 2mcanh 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 opu45.9 ivh .w3wtj bn6btir/g(9yve 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the pr t/4ntb9w 6 i93u.vbehw.i(g5rv po yjimary, 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 and its secondary has 200 tu-7k nvc;rwo c c2dno:(o-)lluhc j59 qrns. If the input current at the primary is 100 A, we can expect the outpnlo)-d qjcl 9n(v-wc5kcoorch2: u ;7ut 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 transformekuuuy/+)+8da/ vzkk7,lvwby .eh a- f r has 100 turns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we can ebyf /v-,.)a/euk7h8v kd++ul zkuw y axpect 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 200 turnfh,r:2bxp,ck7z fi8qq :u:pv s. If the power input to the primary is 100 W, we can expect the power output of the secondary to bei: frp2q,qbh:,: vk7f8 xucpz (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 current at 120 V. The voltage is usua)kri4c hv cs)/lly stepped up to 4500 V by a transformer and transmitted through a power line of k )chicvsr/)4 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 ar+5a n0 (gvthtt 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. F0t5t g(+nharv ind 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 curn, t r+e(xm.)/ejq bzsrent at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power zt(nj,beers) .+ q/ xmline of total resistance 1.0 W. Find the percentage power lost in the transmission line if the voltage is not stepped up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km longampsk q3p+.0ykv p 38sbf3 bm, has a 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 q330,k s v3pf8m bkmyap.bps+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 livamc7ys 4n34j)ywcc/ ne 50 km long has a 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 rc/c7ma3cj 4yv w4nsy)atio of 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W line at 1000 V. How much less power wouoqj2;s4j 1f rdld be lost if the power were transmitted atdfs 24q1 r;ojj 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.z8o5 l*,ln9 mk ih;rxi It is to be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output 9*;il zx5h nikm,l8r obe stepped up with a transformer if the power loss in transmission is not to exceed 0.010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a curre kw/z5(mqai8lnt of 5.0 A. How much energy is stored in the coil's magniakz5/lq m(w8 etic 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-Hs 6pm,q- q(.t*2vtaww(rr h kb inductor. What is this circuitmq ak. 6-rpvww st2( *thq,(rb'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,;rbn +xa3iv z 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 pea5r0:8q3fv1npx*/hmbkyp b wtoso14 ek current?

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98#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What is the rrab 1 -xh5iol wond275esistance of the lamp-b n5d57ol2ih1oxarw?

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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 powe j zl w)dk;*s2oiusn8,r supply. What is the peak current throu ;d , *zns2slo8ki)juwgh the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. What is the poweimb,+jvrb *h 68tvrn 4*fjko2r dissipated in thotb6rv2 8 * fmh*,nir+v4j kjbe 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 ,,g7mppf8mck-+ / qtxewy 0lais $I = 0.80 \sin (240 t)$. 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 irn8nuu73oc b-t4ko wz 8tyg6 77-frris $I = 0.80 \sin (240 t)$. 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 a2xmg; mgmgx2 b 0k yxi-w1+b4q 50-W resistor 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 i;aq/hrh 8i4g r;a -nxbnductor 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 -k.2 wvumzy2fh)c wlo--1zgj 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 inductive reacckf2b-.qcw4kvzet:9 tance?

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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 af dz az/j;)/v ud+ry4gwisn 7(t 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 frequencydv*1r t/e7 e+m p ylsnym0z5k7 of 20 kHz is applied to *vsl/ked7tn 75p ey0m1+mz ryit?

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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 coi0qk89nc,ore1mw 9x*kw 3 u xtnl 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 capacitor at 1h7 qh:9tn; pby oh0hfb4(rq+ j0 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 c1k bereoz/ t,1h.kl6iapacitive 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 a reactance cj,s0gs3 j3q7fj 7xv9tbk rnxpy 8w*7of 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 of a 9jukv :1sqxrfrzh8;bke) d3( 0.010-mF capacitor be 100 Wkf 3 x18uh(dkr erzs 9j:)qvb;?

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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 4 ew (/z tmds5w3*disnthrough a 0.0010-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 resistance, 15.0 oa)4ag c-qpzr*g 1m .wW inductive react.w1 gamgrq *p-zo a4)cance, 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 im1/k-, 8f uvaqp(ushp.d7pnggpedance at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mp -.p87(v fu np ahkq/sgd1u,gF 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 at 150g.p t.(x2cu ubm,3lka0 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are con u.b,gu clk .ta2p3(mxnected in series?

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118#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in seriej4jd dkvo0d. hpj29 +gcv+j p0s with a 20-mH inductor, what is the impedancevdg0 0vo+jp4dc kp2jj+jh9d . at 1000 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in seri0u)0 p z:4q7 bqo2suhyk;jxsnes with a 20-mH inductor, what is the phase angles)ksoy 0n7up4q0qu z :bh ;2xj 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 s8aavff,5mq8 j 37hqeieries circuit with a 20-mH coil and 1.0-mF capacitor for7ve qhf8 ami ,aj8q3f5 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-3r2gqy qil+ b capacitances is needed in series with a 100-W resistor and 15-mH coil to get a total impedance of 110 W at 2000 Hl- g3byirqq+ 2z?

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122#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance must bz61bl,ka6vh(v ay / que put in series with a 450-mH inductor at 5000 Hz for a total6, aq1ybv/zlh(uk av6 impedance of 40000 W?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in series withmx*)pdg dc,l i m )ot9x/mln/, a 100-kW resistor at 1.0-MHz for a total / ,mxdgmo)d9,)lmc* xp /ntliimpedance 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 is the impedmji9 kw(g 5t,vanw (m9ji k5t,gvce 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 ke4v,l w/+kls gHz for a total impedance of es g v+wlk,l4/45 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 wg. f*u+x)wthq*u y bf,ith a 10-mF capacitor at 1.0 kHz for a phase angle of +*gubyqwt.u f )hx*f, $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1.0 kHz emnpj+txk7 (csje -94h7 o6kx4kl,kx for a total impedn9jsl+xk7kj (-4hkpc,kme o4 xx 7 te6ance 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 atn)*bl06dq h unltmm t35ve2 h6d3 s,ah 120 Hz. What is the phase angl ,n 6 q6l3hsh 0mbehtmualv2td3)n5 d*e?

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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 1d+,jho- zxf1i.w ,crzo4 o7iv500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in ser, hzzoiviw+dr 7x,c4.1foj-oies?

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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 capacitor, anda:dtpe 7.bqfrb8*a d4 a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz powe7bpq:b af.*at8 derd4r 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 capac( w0jhtq+xhmyb s7,s;iy x( :aitive reactance 30 W, and an inductor of inductive reactance 30 W are yjmx;+ ,h0(b7t(sisyh:xw aq 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 containingg*f,m+i.id 8.yy ae,by*q evc a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor,yd+eb cf,mq,g *..evya *i8i y 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 rew,;yb hh jvsi2ze q/e854a+0d zvs,srsistor for a phase angle of bsi08h; qve/ j+ vwsyr54 hd,zz2ase,$40^{\circ}$ at 10 kHz?

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134#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit has R = 20.0 W, L = 200-mH, C = 10.0 mF. At. u x(px ,;l5omwi+igf what frequency should the circuit be driven in order to (pu fi;.+, ml5iogwxxhave 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, 15.0 Wv9c* m5 sppr3m inductive reactance, and 10.0 W capacitive reactance, when the circuit 5pvm rs9p c3*mis connected to a 120-V power supply?

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136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an AC circui0ax7(igl -o3s0 8q0wdm hwgdet 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 resl38b vm 2gh0xrd5+lucistance of 30 W. What is the0l8r2c5gbvlx3mu +d h 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 :w-w9 len+kfr for a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a k+wl n:w erf-960-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 a29q cr/7u3v3gu;+ j pimnbham 1.0-mF capacitor and a 15-mH coil in series?2nivu33j 7 +p huagmc;/qrmb9

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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 s mg7u8 ( i49c4faj axqmuid.2peries with a 4.7-mF capacitor for a resonant frequency of 10 kH7 piagui9 qjm 4ma2( 4cdu8fx.z?

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141#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is -g /l)z 9dzzzlneeded in series with a 3.7-mH inductor for a resonant frequency of lzlz/zg -zd9) 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 9d y -k083wi9jut pskka 30-W resistor and a 40-mH coil if the resonant frequency ofs9d jup-yi0w39kkk t8 the circuit is to be 1000 Hz?

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