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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 flux excepqo4v dk xr-gb.9/y4qx t

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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 ind, bzvmq5o-z2tvui+ptxc0 t0;uction 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 wijmfd); b;b9: nm*uz u-p0kdpf re in a coil produces what kind of change on the induc;udp9)mb b- pd uf m:zfnjk0;*ed $emf$, 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 tu(t3e:vps kn j 39wmw4he magnetic field through a loop of wire produces what kindknj m:wtve(9p us33w4 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 change ol g8dh fnz96tr(odh ,9n the induced8d9 rfh ngl,6(t9hozd $emf$, 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 m9i -wv28gwakl agnetic 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 inducedi wugn*j ;p3d 8.otd4c current in a conductor will be that whicc twu*3 .dn;pgj8do i4h tends to produce which of the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A bar magnet is held above i:j0 x 5ubxpd:3 dpwz(zts center w5d pz3 zjx0 pbudx(:w:ith its north pole 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 bar magnet is held above w-8x 5rl ub7e4sqs9i; xruwx6 its center with its north pole pointing down, ixrxsx 6bw58 u9qlr;47 wu-e sand 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 n-s.a l9kl *ultable top in a region where the magnetic field vector points straight up. The magnetic .nukl -ls9 a*lfield 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 t9p: a:h/coqqbhe magnetic field vector points straight 9c:a bohq/q:p up. The magnetic 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 top0i- i+kg efe+k in a region where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, what is the direction offkik0+e+g e- i 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 cqly zgkw -zbg0 gju51(p:kt;) s 6 1*lq-lrmjbarries an ever-increasing current northward. Two coils of wire lie flat;)ylu(50qj g sk-6wr1 qzglb1mz *t :kpjgb-l on the table, one on either side of the wire. When viewed from above, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls through a loop of w-jo zy5wh2q6x ire with the north pole entering first. As the north pole enters the wx2wzh56 -jyqoire, the induced current will be (as viewed from above)

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15#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angl;op33v+wz( o38oy jz5i klozular 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 th;vo+j iy5o8l3lz kzp( oowz3 3e 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 consz-1p2 eqez:autant angular speed about an axis whose direction canaue q :zp2e1z- 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.; ffkmrwbcqt :a(((k -
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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:7xn ldixu4zfz3+( nuua:a a7 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 magnet(so v a-k(y+ m9vhm7viic field. The $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved northwav 0-v c:oiq ifesb/-q1rd at constant velocity through a magnetic field that points stro fv 1:-b0iviec sq/-qaight 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 constant 9cd(fx,nm1 vgyo tc:7angular 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 transfor;*onp/wv p4c v wki7;p5gxs6rms

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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 o *sd3of /;gvc56w:yrfpa 2yc frequency of th 5dcg*crs of2p/6 of w:y3y;vae $emf$ 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 u3zbn0tms6je, sed 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 kra(t+llwb:j)r ; q.yls15s /wfd . ovthat

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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,l0+qdd +zs*q og5 c5.fauypy coil contains more loops than the primary coil then q+5y+pg*yqd0ld5czf.o sa,u 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 thesb ra rtu p 5qh0 jp-.9c.frt5-u,q0xz secondary coil q5 0 j-p0u.sqzx crtu.r59t-pbfh,a r then 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 ivhb4:td6 77fxgk 9ea input

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30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a given LC resonant circubjy;j+(lrp hfd/t .7u it,

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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 connp7 q-mqrjw3(c ected in series to an ideal battery of constant terminal voltage. At the moment contactm( pj37-rwqc q is made with the battery, the voltage across the resistor is

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected1mte(g 0tgb 3j in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the vol0jt1mbg3e (gttage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is conne(ehj)b9g ujp( aj l;l5cted 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 +qye5-v 6sg:.tnlucu 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 sca-gno0 n4h 1v- 1mdqin series to a battery. The time constant for the circuit represents the time required fo1v-samqgc4 o-01n hndr 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 inducto7by,p -y4dzgh i xd 4;ayvsiwp) h):1gr are connected in series to a battery. The battery is suddenly removed from the circuit. The time constant for o74 i: yp )yyd)-;1d4,xavzggib hhpswf 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 ynt5h 0qe8 m2cd;sw,cthe 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 power supply. On this ci6f s, gq i,fs+n)job14:rj)8wtoa 8kyebxx+trcuit, 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 mlb7n qj2x9l hmig6hj0,.f6x supply. In this circuit, the currenijxhb6m.29 xgmh 06 nf7lq,ljt

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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 factorb3x2mr ok45v r when the frequencmxv34r b5kro 2y 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 an inductor ix12my; 8z29wsvs tfc8yn zr1 *uamli1s doubled, the inductive reactany 2y21cmialfsr*1mt wznv18 8;u 9zsxce of that inductor

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across an inductor 3g.1 wi dasm/papproaches zero, the inductive reactance of that c pd/w.sigam 13oil

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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, thgxsl0;wl ,r g 0b7xo/re currenx0x o/;wls gl b70grr,t

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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 w bwor(y4 qud+*hen the frequency is tripoy4*rdq+ w bu(led?

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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, .gvh0rqilcrwsh7 a40 pv78k : the capacitive reactanrcsa 7 qr4w i:vgh7vhk 008pl.ce 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 i o73/idjery67k dzlf 3n a RLC sl77/kdyi 3 oezj 3fd6reries 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 RLCob ih.s53 l0g86-w3sozi+fz k3ccjt b circuit is defined as $\cos M = R/Z$, but the phase angle can also be calculated from .

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48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance ofsr4(wvp w:aud hzt;+ 3 the circuit increases if R increases. When is this statement tru v4dhuswat pw( r;3z:+e?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circ,s )m;r zsy1je.k)edw uit. The 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 increasenu6scxy b: 7;js 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 capacita;-))aft mt d2i o3hhponce both double in an LRC series circuit, the resonant frequency of thadtf-thami;2h) o3o) p t 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 drivy f/c/0:ofhp uen 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 homp (gs:lal;b;w q)*circuit 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 ra *g-v 4av,ctbj */jwadax ef5)dius 0.10 m is rotating in a uniform magnetic field of 0.20 ,f*a4v */ba-) vxjj dt5gceawT. 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 magnetic field of 0.20 ws 3b5vav95*rsk vit1 T. Find the magnetic flux through the 1 *9t ikwv3sbs5 r5vavloop 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 uniform magnetic field /j.o7zmc z wm4of 0.20 T. Find the magnetic flux through the loop when the planeo/.zcjm7wz 4 m 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 ofjgpo zodgu x2 5xlya:*d j+q9c/l5l -( 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 coii6q3.e 7 eakwnk (wm8vl 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 umfqzp :op/ 1(3 bg7rv6/v grgturns of wire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.5 g/pgfv o/zb63:1(grr mvqpu70 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 a nlq9 .0nxq-eu,z3j5wty7k wan 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 an1*a13ogi uv zw:cbf3md area $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span o,*urhii se1-ovpo 87 5 hux9px. xvi8ff 60 m flies horizontally at a location where the downward component of the Earth's magnetic fielde,1pifuho*x5uv- rpov78x 8 sxh.ii9 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 conshc uz+ u+zacf- hvu2l-(v-gg .tant angular velocity of 2.0 rad/s about a vertical axis through zh-2hc f+(-v cv g.gzual u-u+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 c9/ -:5 4xdnewb/o begvagv-xcross-sectional area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns of wire of 8(uj6sqlj51sruj* qg 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 i;5sj 98uysuq9pbv( cxn job)3/m er3 fts 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 rotat(qjfx8bu;ju /3nce 395 ob9yp v)ssrmion, 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 zeeolhhd3 07y p73 rsjzb:.m2 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced current.

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that you wish tofd y e-bt6*5pc construct a simple AC generator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is av-ep5 tydbf6c *ailable. 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 wit zu jjii9jpu8,nivz 9t35e6/ ch 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 oqwd(wt08id/ x* w epr6 /jl8oif 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 oper0 d:eqxft1 qxk;::vvs 5r c+xcates on 120 V AC, and when running at full speed it gsc v+dfe:cx5xq 0:v q;:t1kxrenerates 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 1i 3afe*yrtigbs 4i :,resistance 6.0 W is connected to a 24-V power supply. The operating current is b igt* 4 se1i:iafry,31.0 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 supply. z9l4;lqfm)y /(h4m .kcyj hud The operating lh9 ml)/ 4c4 zd;yqmjuhky.(fcurrent 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 resisqqcn+ yvw s7x/be05v (tance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A at full speed. What isq 0cbex s(/ywv7+vn5 q 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 primary voltagev/1 riwzl:9 y: )pi 97iavmczo 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 tra+cu2 6qqru t,yu /lw+wnsformer causes 14 A to flow in the secondary. How many turns are in the second,w+ 2lcu+qqy/6 t uruwary?

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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- :yubxcg55 eiey 9o2xlc;b,d+V primary if the 24-V secondary has 100 turnsc2duely;5, b o:x+ c i5e9bgyx?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consiixt.w) 6opf/msts of a 500-turn primary coil and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what is the current in thew)6 it. /pfxom 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(qag*z6zm 5x et(dx 7n transformer. Assuming 100% efficiency, how many amps at 24 V can flow in the*emtq75 xn6 (zxz( dag 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 +2 2x im9+tffrzwszwz1; emi(.0 mA. The primary coil operates on 120 V. What does the primary zz 1i2;x(wwst z9++r emf mf2idraw?

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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 pri1d;vi;k lq 2 v7e5fa (lc u0a-r7zxto ltedk26mary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to fzd0;tixu2l2lt re5 k c;ev1qdv(la 76ok-7a 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 ou 3zbs y)hef9(yo be4vtb*6) en its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the pe(z 9 )hbtb63 yb)euf4vesyo*rimary, 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 turns. Iffj m42gkel3f 2 the i k3je 4mfl2gf2nput current at the primary 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 xr 5b115xlbnmits secondary has 200 turns. If the input voltage to the primary is 100 V,xl n5 xrbb15m1 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 100 turns and its secondary has 200 turn )gz/b/(evt)o z1kvaspzj 98ns. If the power input to the primary is 100 W, we can expo ztz anv/z 1)gs9( )/bp8vjkeect the power output of the secondary to be (neglecting frictional losses)

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87#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usually stepped m6b x/4q4d rueup to 4500 V by a transformer and trxbq/4du4re6m ansmitted 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 voltvrj y:vdx x nc)xd)x/ r-safk181,ys )age is usually stepped up to 4500 V by a transformer and transmitted through a power ydfa,rnc d) vsxvj-xx 1y)s)/1 r8:xkline of total resistance 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usuhxv:ia i2jd5* ally stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lost in the transmission line if the voltage is not stepped *:5jhiivax2 d up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmissiond4 t nwe r:m6npuy218)pbn )jy line 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 ratiou pdbnerytwj2 ))48n 1 n:m6py 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 k58 vc8 *iak8p:zobbedm 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 ratio of 100:1. What percentage of the original energy is lost when the transedazp8bv5i 8:bk8c*o former 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 dqy.i2je+zumbp 7x v.;m* ubr 7own a 6-W line at 1000 V. How much less power would be lost if the power p rvzy m7uubme+qxi2.7 *.b;jwere transmitted at 3000 V instead of at 1000 V?

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93#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The output of a generator is 440 V at 20 A. It is to be transmitted on a wi ;2re4nu;jo 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 original power?4u; rojneiw2;

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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 stor(8aicvh / c :6lnx,adced in the coilhc ,aa c86vd:lxn(i /c's magnetic field?

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95#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A simple RL circuit contains a 6.0-W resistor and an 18-H inductor. What is 1/n6 eiz /pqqi r4ov:ithis circuit6eii qz o q/p1r/:4inv'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 volt9+lj up9r wo kgrh(o s,ajv ,jo85y**qage in an AC circuit where the rms voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What is the peak currenke2zrcxq 6 6k*t?

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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 resistance of fcahi3euk mh gqk y)o9+q:+; s+ natn):t *fu3the lanf ta 9qn++muok3ieu)shcgqk): fa+ 3th y*;:mp?

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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 ta:vgxt 5(hnq1avzs,w05 ,(xe 5xjjf -V ac power supply. What is the peak current sv(xqvj,t5gx5f z 1 t:wnje,(5aa h 0xthrough 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 pq9nc:zjjk0ws-+ i y.a, trd2 power supply. What is the power dissipated in a-9wjtip2q rdks: c ny,0j. z+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 7ww/r.1 -uurnc reh.s$I = 0.80 \sin (240 t)$. 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 re-rco jgyy6(u; 9dn 7brsistor 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 resistorjocv71* m y px:yp.5za 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.wnr9 zt z gzbc8.cj; 2r2a6kk10-mH inductor 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 reactanc7afp(w3:bv qk v,:juq e 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-j6z nuy6hds4 5mH 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 inductive reactance at 10001 d vf.qfyhl0wp 2yety21-t5r 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 at2z l pi-6 p5)f(kazty:.zs5(br ydmuxm)mx 5 y a frequency of 20 kHz is applied to i )im2r fyz5)zlmd5zyx (:syx 65.tkapbu ( -mpt?

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109#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 2.50-mH coil due to a 110-g p 5*)etzfpf8V, 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-m o+bl8y 28eldx zx:mb8F 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 )om9 ;ne/y p21xb qkegto have 50 W of capacitive 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 ay0z8p2yeuj:h ny5qq0 k x s*n-zl (u6of 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 *i45zc uel8l,2gtuia a 0.010-mF capacitor be 100 W?c8 u4l25 eg,*iiztual

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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 1000 Ha35- *q v9eoe+9qdkczgsxi 5p z 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,q * tk/xi)orqdkl5j/ 4o9ei r: 15.0 W inductive rea oq/r9r*x l4kitk:e/o djq5)ictance, and 10.0 W capacitive reactance?

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116#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the total impedance at 1500 Hz if a 100-W resistor, az6t5 thzzjsr8sf xv4my 54,;20-mH coil, and 1.0-mF capacf5mhz46ajsy8t sz4 , vz5t ;rxitor are connected in series?

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117#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle at 1500 Hz if a 100-W resistor, 20-mH coil, and u 0i i zdd+1uo2otxl7:o-n-atlf*h l41.0-mF capacitor are connected in seoxldn-u 2tz 4fat-hd1ol+ oi0:u*7 ilries?

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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 seriesx doqc62 ffz8* with a 20-mH inductor, what is the impedance at 1000 fox8*cd6z q2 fHz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 2z().l9 lc0 hk 6jsa,9cp glggc0-mH inductor, what is the phase angle at 1000 Hz?g9jl)(kgg chalc9 0s ,c .6zpl

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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 m5u l/;d-kl/w+ utqp y20-mH coil and 1.0-mF capacitor for a total impedance of 10w u/lt5p-/ qu; +dylkm0 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed in series with a 100-a8q 8-ab:hm ib e0lht)W resistor and 15-mH coil to gebh 0- l88q: amthai)ebt 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 at2 v3:j ;3xgn2mgwhjjn 5000 Hz for a total impedancemwn 3gjgv;jj322 nhx: 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 serie1ku.j pz*vme7t:k8 mr s with a 100-kW resistor at 1.0-MHz for a total impedance of m:zu7 1ejvrmk *t k8.p150 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 capacit4gf121lj nae:lk 0h tsor. What is the impedjfln1:a t4ls20 hkg1 eance 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- 3 cuh8la;s)tngmt ;e;, xu5ndmF capacitor at 1.0 kHz for a total impedance of 45 W?gdhtxcu8 sn,;ma53e ) tl; u;n

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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 s.soc u5s 7:gca p :l62*nktmkzeries with a 10-mF capacitor at 1.0 kHz for a phase angle ofps6ut: *2ngck 7aoclk5 ms:z. $40^{\circ}$?

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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 1.2 m (qkzuf7(f nxk :x1n4k(feb0 kHz for a total impedance of 45(2 bxe zmk :nqf(nx 1f4ku7kf( 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 withjxw s4 ,t/ t tqms36q/th7x;ka a 100-mF capacitor at 120 Hz. What is the phas s/qa 7x4qtx twh,s6/t;jk tm3e 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 V and 1500 Hz if a 100-W resistor, 20-mH coiz yp:(p sjc)f+l, and 1.0-mF capacito+j )fp yczs:p(r are connected in series?

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130#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit consists of a 100-W resistor, a 10.0-mF capacitor, .q mhsfo* 3is 9a/jao/and a 0.35jm iaq.ss9/aho* of3 /0-H inductor. The circuit is connected 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 reactance 30 W, and an inductorxdnc/ol r//1s 3lyjs, of inductive reactance 30 W are connected in series to a 11 xdo //jyls1/crl ,ns30-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 cqi63i)e dg7 ) kg)d pq4t48xptbdzu5m ontaining a 50-W resistor, a 10-mF capacitor, andg4d btqzd)m7 i)54 i gpde)p6q3ut8kx 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 nece xw:gm r1x1hd9o ;u1thssary in series with a 500-W resistor for a phase angle of:o wr1xhxdg 9hm;11t u $40^{\circ}$ 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, Lm qdn2:-4eoyu)h 7ydx = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferred from the drivinx)y7 oeuh dm2 -y4qd:ng 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 outpu :3**gb2is2b-bk- ifsvb*zmvg l2 tz et in an ac series circuit with 12.0 W resistance, 15.0 W inductive reactance, and 10 zvblmi vb-b: ksb*22*zs3tgf 2* ieg-.0 W capacitive reactance, when the circuit is connected to a 120-V power supply?

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136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an AC circuit gqu/. lt9y;l +vgzvk* 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 resistaej: uci6nd6t2ym( nao ru9bnc,*t:z5nce of 30 W. What is tt j6uoibncn yr:t9:6(c5,2m ud*ez an he power factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series RLC circuit conta vqsd)) er2g0pining a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power s0) ges drp)2qvupply?

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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-mH coil in(:t jog-;w5s zsmf,r d series?;odgsf: t5 s-,mzrwj(

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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 i4 h;h t*icq*ain series with a 4.7-mF capacitor for a resonant frequency of 10 kHz?;4ahc **thq ii

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141#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 3.7-mH inductor h8ynl**:exlwsx 2.ftfor a resonant frequency of w8yl.hnf:2s*x *telx 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 mustgkq3) k h,:xuz be placed in series with a 30-W resistor and a 40-mH coil ifqh,x3) ug:kk z the resonant frequency of the circuit is to be 1000 Hz?

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