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

 作者: physics   总分: 142分  得分: _____________

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

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1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following are u2m a nfpqvn.vh*-9-lanits of magnetic flux except

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of inductionbxt ru:e ;9kl pxe47pogo)f9,6 lue; s 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 in a9ea3p i /cf:9tmwi3nf3*)2ttqj jra m coil produces what kind of change on thtm/f 23twj9ie arn933tci*: a mj)fq pe 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 magnetic field through a loop of:6s2v sq zo0j)tia.vj wire produces what kind of cv)2j.sz06q tia :svo jhange 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 loopu dl /3br/f(an of wire produces what kind of change on the inducefda/(bu/3 rln d $emf$, 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 m+kh*agx d.- cyagnetic 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 induce4ckq/1 ti6ow0 pa:q whd current in a conductor will be that which tends to produce which of whtpq0oi / 416kqc :wathe 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 horizonta+khldyx/7 6kr l table. A bar magnet is held above its center with its north pole pointing down. The stationary magnet induces (when viewed from above7dyk/l+ xhk6r)

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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 tablej;9vj*mi h y+h. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, thej9yi +;* mhvjh 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 if fctcm .j0584-cnsx tn a region where the magnetic field vector points straight up. The magnetic field vanishetcncf4m.-j 8ts 5f0xcs 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 ta(iemb2kaj1c*y ( 50)nccfq va ble top in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stroyj(n*c 2i0c vbqmaak1(5)ecf nger. 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 tt:jl;t6 mnjiil.94y qop in a region where the magnetic field points straight down. The magnetic yt:4 tlilm6 ;jjn.i9qfield 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;f y; y5xfewz3 on a horizontal table and carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either sidy ;zywfx;5f3ee of the wire. When viewed from above, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls through a loop of wire with the north :2mu-.z,drox ydnl4spole entering first. As the north pole enters the wire, the induced-nmdlz:xr ,.4dsu2 y o 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 angular speed about an r z aqydc*f*/:8o4ol- vip f9uaxis whose direction can be varied.fco z/opfi9dqu*84:la*yr v - In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be zero?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angular speed about an axis whost x41)g3 ekxtvna g. hvgk pl0)9)qrv:e direction can be varied. In a region where a uniform magnhqx :pgtxkg)t03) nvv9vk)1 4grle.aetic 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.x4ej:ec7qz.d o s -(qi
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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 thatp: fea p/)avy4xn0s7n 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 frmvu.-j0xms1 n*c1 vp vd:lj/lh ; gb-ield. 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 (orienttyog yi+7te(1;l+ ywa ed in the east-west direction) is moved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potential indo+g y7yei;1+ttl(awy uced 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 angu +hx *5htu9txnlar 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 trannwjs5bna :+owk/ e3l5sforms

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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 secney 5c3judibfj5 4 :w,ond. The frequency of th u: jjc5ey43bni5d, wfe $emf$ 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 devic ou9f7y5 1som8ffd4*b.zu dlm/ fc6lm e used 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 thail *5 p,dm:fmwt

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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 coig.ye8q.8j psgh/gha 5l then h e.g/.j 8hgy58pasg qit 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 loodb6.kkl2a t6p/6b s9dlrhqx +ps than the secondary coil then it is 6slbdxlqdb 9 p+6a/6rtk. 2 kha

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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 inpuklct4p(iz fw;h(0jge,:/u2si 5b h r st

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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 circkb tl1li3p9 tc6 gue8:uit,

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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 dt-p,ninve;; . 5pbo bbattery of constant terminal voltage. At t, 5d-ev;oibp.tnnb p ;he moment contact is made with the battery, the voltage across the resistor is

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to ,s6-m xuvf:n)ztowp6 an ideal battery of constant terminal voltage. At the moment contacto t x),f6npvmzs 6:-wu is made with the battery, the voltage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and z2 (0)i.x 83w7whql/xz /y jzo axsmyeowc 7;tresistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the inductance is 2L. When it is connected to the same $emf$, what will be the final value of the current?

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is xkhgf 12kl4b q hjz./6connected 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 5.*ev1 c7vs sygb- (lsx,zp eutime constant for the circuit represents the time required for the curren vvecg. p7sbsls51 yx(*-,z eut 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 inducts 1z mfnq82g*7cyo1fbor are connected in series to a battery. The battery is suddenly removed from the circuit. The time constant for of the cir*1yo f 7z fcgsb2nmq81cuit 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 sa- 5djj 7w*de/fyga (ryme 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 toh kf.q ss3r42d an AC power 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 supply. In this circui+ipweipw *iha: /lbt(9vm2 l )t, the currentb(lw :ehp+im29vl p/)a*iti w

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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 ac4lkld3p0 sf.qe z+yn 8 circuit changes by what factor when the frequency is 8z4slflnkq 0.py 3d+etripled?

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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 is doubarcf gxn;4i:+cimy f/b( d+ (xled, the inductive reactance of that indu4ci +;(cb/ (fmg+y niafxx dr:ctor

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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 acrom 3x0exo-ks; tw8fk+;fxa.dm, xu1ef ss an inductor approaches zero, the inductive reactance of that0 ;+sd- emkk ow.xxm1x,xef8tua3;f f 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 supi/o42 pbvmn v9s-f9o qply. In this circuit, the currev4n/9pv2 m-bs ifoq 9ont

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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 changesr8 p)-.onhrrz*3h ic m by what factor when the frequenzim8- h rrro)p.3c *nhcy is tripled?

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across a capacitor approaches z: ,yud atu-il0j s/mp4whu)/d ero, the capacitivuwuyt/ulmh/ :s pi j 4a),-dd0e reactance 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 o9vgd,rgx2w 0.id* i gcmrz.r+f the inductor and capacitor in a RLC ser+*m 0 gzig2ir d.9vcrx.wd,g ries 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 defilbws:tiz);m (bkovz5 ijs . 1/t0(xerned 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 ift8etyzv 1w: 5n R increases. Wheet:t5vz n1 wy8n is this statement true?

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the circ2fhc3z*q1 pa sf nn,e.ua9.dyuit 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 increases 352vmt-jpgfm/c +yem 9dp hq/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 capacitaco a-rggh ,)u)3* cijynce both double in an LRC series circuit, the resonant freque,3g- cao*ij )yhrg )cuncy 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 by an AC applied voltage. At resoniy5 :fg z5k;utojk d0)fd/c 5i3lo q,c.k4avqance,

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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 circuhf/pixhd h// d mf.ad;4 1swfuot t0 tz0*-*uait 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 iny)xtgzdw td.c) 3ki( , a uniform magnetic field of 0.20 T. tw , 3dd)ckgz.yx(t )i 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 0.10gx ; *wisy9;n5ozbi:s m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane ofsnizo5 w;sxb:* 9gy;i 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 of wg -)die ,41 e75yztdsbfh 8tp0.20 T. Find the magnetic y7d eet4s,8bhpzd5- gf t) 1iwflux through the loop when the plane of the loop and the magnetic field vector are at an angle of $30^{\circ}$.

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional arhf*+ok tx q:7kea of 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 changes fsp3p tm 48zbu1rom $4.0 \times 10^{-5} \; Wb$ 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 sidescsm+b:0x x t; ,kcr cp-;9,vres gzc7u 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coi 0,;,cp e+t bvz-rx9r k;smxg ucccs:7l. 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 di( p5//fi .t fizzrr-and an area of $0.40 \; m^{2}$ is placed parallel to a magnetic field of 0.75 T. The coil is flipped so its plane is perpendicular to the magnetic field in 0.050 s. What is the magnitude of the average induced $emf$?

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62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil of 160 turns q0bfjj(1 a ;djq9 4cwqand area $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span of 60 m flies horizontally at a location where the yr.vl9l c1mr26bw v49so*o zldownward component of the Earth's magneticlwvy2o 9 l4*vmsblr9 1o 6rc.z 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 peq:s o7itpg-sg59b8u. e p5yvelocity of 2.0 rad/s about a to9e5bs.p p :pu geygq7s -5i8vertical 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 are m3z w:v*.kakja 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 cons n (pggf2 t)9ae*x9dcsists 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 armature. Each loop is 12 cm lots83q fy.:y y2l8 +tv5qtp sifng and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular to the axis of rotation, what will be the maximum output voltage of this gene p 3t:tlsy+.q yyst2qv5if8f8rator?

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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 svvk 1( :0x bwgx2bt3bof 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced current.

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that you wish to construct a simple AC generator with an output of 1 /s/painfa1)z2 V maximum when rotated at 60 Hz. A mag/znf 1)siap/a netic 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 generatorho6 po/hh 8t,e b,(j+gj*gacv 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 re1.:bdxoh 2xwvsistance 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 ro6- dl q7swa1resistance of 6.00 W. The motor operates on 120 V AC, and when running at full speed it generateqwad o -67lr1ss a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected nwuzi-y;8,6eu a,7 6 qm oidgato a 24-V power supply. The operating current is 1.0 A. What is the st6n8giiuaaewyz; q-7,du,6 m oart-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 i5(ufsll5o7kbd , 5np 24-V power supply. The 7ds5 5fp ulki5(,bonl operating current is 1.0 A at full speed. What is the back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 2) 3kci x9xw-xw5w2tpi 4-V power supply. The operating current is 1.0 Aw2wwt pcxxx9)35k i-i at full speed. What is the back $emf$ when the motor is running at half speed?

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76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A step-down transformer is needed to reduce a primary voltage k9 w48opxvn q0of $120 \; V$ 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-tur;q huw(:bcxfod70 z -dn primary of a transformer causes 14 A to flow in the secondary. How mhdqf0b -zw ;o7udx:( cany turns are in the secondary?

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78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, how many turns are necessary in a 110-V primadaum4qwn96p c3 jy48nry if the 24-V secondary has 100 tuwpnyc u4j6q39na d m48rns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consists of a 500-turn primary co *9ko f48ws74qyvcab5oc vg(m il and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what b4csy5okw8*f9oqvg (va c7m 4 is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primary of a transformer. Assuming 100%lf+ cv9 42*c-wg irkqkr1uf)s (n vws1 efficiency, how many amps at 24 V can flow in the second) i( -kcv91*u1gsf qnrv4f2lswkr+w cary?

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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 i3oj-h2/wo xz3 twl2ssign transformer provides 7500 V at 10.0 mA. The primary coilhw j3ow 3o-i/2ztx 2sl operates on 120 V. What does the primary draw?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coit8j3 x vb/r2wsl.btw) l and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage i /xtbsw3)8lbrv2 t .jws 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 .pka )y.geup9v 91oud its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the second.p kv.9e9g)1yap duo uary?

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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 k(2ia*jvrnk .a*s( jsand its secondary has 200 turns. If the input current at the primary is 100 A, we can expect the output current at the secondj2vn*s(a.k(a is*rjkary 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 hizr*d+ sogd*iz di9na8faj w7 ;m889sas 100 turns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltim j8 8sa8g i9dn*;szr+f97wddza i*o age 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 transf7)fagz-1a g.vouvd /gormer has 100 turns and its secondary has 200 turns. If the power input to th o1)/gavv-7.fagd uz ge primary is 100 W, we can expect 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 voltag8* ousdei1z /agdq1+o e is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance *d/ozu gi1 o+s81 deaq1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usually svclv) /zq2(zw obu8c 8tepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. )bl82 u/8 vcc(vq zzowFind 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 usuatgdmu1 vr.p 5s :6v;qjlly 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 n5 d 61pv.q;vgjtusr: mot 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 resistanov 7*js60lhd- dwmk8 ice 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 transformero-wim7 j6 0v8dh*kdls with a turns ratio of 100:1. What percentage of the original energy would be lost if the transformer were not used?

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91#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a total resistance opk7u t)mete6a) m6)faf 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heau6aetak) m6mtfp7) e) ting 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 line at 1000 V. How much less power would be lf 9p x.pubof-:j::)m enhae/z8j(kbtost if the power were transmitted at 3000 V insteadtjokx-)::a uphjmbp: be9/fen z 8.f( 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 s;:sw7ypzkx18o szp:be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output be sts:p81;s7 wko zp:s zyxepped 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 current mg0ce:o* twubgo/em 2p2/o5 jof 5.0 A. How much energy is stored in the coil's magnetic fi// t2 m5c o p*gb2m0oeweogu:jeld?

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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 a;jub ody-a4-w nd an 18-H inductor. What is this cirj;-a u4-oby wdcuit'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 cizew328++qy ddkc thg f wy-+yi 4ebw-5rcuit 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 place/g(7 nnj (ok(5n lpfzyd into a 120-V AC outlet. What is the peak current?

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98#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What is the res dzwh) mmvt2,qnj,x; ;istance of the lam; ;nd)zjxqtw , mm2vh,p?

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99#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. Wh-k(f3jqgxn atc 5h /:xat is the peak current through5aj3qftc - (xgxnhk: / 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 ct +ha841cpvpf3k k 2mgpok8q8hil/1xonnected to a 120-V ac power supply. What is the power dissipated vxi1ktm8kc13lphqg2 o8a /p h+pkf 84in 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 jaxzlomumt.* +szj(a1j u528 $I = 0.80 \sin (240 t)$. 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 50djm1d9jv . 3m)xzm4oa-W 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- sjk:-:gl1cz:mo3jcx tt3w k ,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 inductor at 6, y.:4/ +ics vt qgdj kcuympj;7d-c/y0 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 2ih d3*cm9 ta i,5j(gc g5oims1.50-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 indu2f4s*z+xa 2vydy s8z pctive 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 1000 7v /g,ew awvaxtydf 8 1(0ca.dHz?

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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 1 v gt**qq nhp+;wms.u0br7* omcaij:6 20 V AC at a frequency of 20 kHz is apq:a.b cnsm*pg;i * 7 t+j0or6 *vmwquhplied to it?

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109#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 2.50-mH coil due to a 110-V, 60.0 l ;0:iqrsxl 9o7ihs b2Hz 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 reavd/1h r;vobifp t7f/b7p,e. hctance of a 4.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is needed to have 50 W of /f/ ghy,cqg3- 5)9vxewbkdm h 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 capacite66 uy jihvju7x9e4h)or have a reactance of 1200 W?

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113#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will theujqny5j:ws ./ b:lgyh0 mm/3(liic 0m capacitive reactance of a 0.010-mF capacitor be 100 W?:wjih mu/.(mc y3/sy0:ib ljqg n0ml5

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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 10*gd 1qens9n;d w /3dhifmg1wq-m0j 4 w00 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 1 ( vthkrl7+me,2.0 W resistance, 15.0 W inductive reactance, and 1ketr(v,hm l7+ 0.0 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 h rq7 e3xxo/1/l-cvsg Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capac1x3x/h er c -q/vsogl7itor 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 1.0-mF x n;w5vpni.rmo l0 n8r9ll69bca5io;l 6. lmn n bw9lvrx9r80nppacitor are connected 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 series with a 20-mH iozht)ptl03a z;oz/5 vvt,iyt. v ,uu: nductor, what is the impedance at 1000 ., tat /:i3l ytt;p),5z vzvv0hozuouHz?

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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 20-3 csd/*vf dcrsi3v:-ro )9kax mH inductor, what is the phase angds3a3 vk-*) vfi9dc :/xroscrle 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 oiz88 niwcoz7u 8r )/na series circuit with a 20-mH coil and 1.0-mF capacitor for a total impedance ofr7ozin )ow8ic n8zu /8 100 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed in series with a 100vnb 5omd:6v 51(g 1oxhrmn9 bs-W resistor and 15-mH coil to get a total impx ( m6 9h5 bnvnvgbd1:ms5oo1redance 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 4)q 6vg qjjojrnf)8s)m h7/xpu3,i0pu50-mH inductor at 5000 Hz for a totagq )0prx7,i)mvj3ouj pnf6h q8sj/)u l 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 with a 100-kW resistor at c)q d2 y lw;nn0v/xds*1.0-MHz for a total impedance oyx* c/d 0s;dvqwnn)l2 f 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 connect36y.p-1 j btcnwyny)hry27 g9 dmuls-ed in series with a 20-mF capacitor. What is the impedance at 1000 H - t93 suwyypcb6l-2my 1jg 7)n.rndhyz?

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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 cpuc:p6kw(wxgp , y8 k)apacitor at 1.0 kHz for a tota6kc,wgy:)kpwup x8(pl impedance of 45 W?

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126#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series /x+3te;f e; d wvpfqs)with a 10-mF capacitor at 1.0 kHz for a phase angle ;+wexqdpvf; fse/ 3t)of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1.0 kHz for a 6ly seqjyu0m,be x (po8,a n2-total impedance of 45 W0 yq2 m(o,,-yje bu6xas8 lnpe?

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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 w0m*.tu r txn yf)yz1v7ith a 100-mF capacitor at 120 Hz. What is the phase ant).tf rz mu1*nyx7y v0gle?

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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 u et,rf9*l+da 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in seau+ l9t,frd*e ries?

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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-(um24opp5m lil e() gtmF capacitor, and a 0.350-H inductor. The circuit is connected pe 24 m(mltop5u)(gilto 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 in fal;k4j1 bs1 ( exz0haspq-x9ductor of inductive reactance 30 W ares1sxae1kb;j( 4xp h 0fq-a 9lz 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-W4he* 2ptnjp.h73xruq resistor, a 10-mF capacito. u4h q phexn7jtr3*p2r, and a 0.45-H inductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series.g*+yg+rdp yt i8oz. r with a 500-W resistor for a phase angle of y r+..*do rig+zygp8t$40^{\circ}$ 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 what frequen;3xrieue,g3x xyoq8/l k h n;.cy should the circuit be driven in order to have maximum power transferred from the driving o;h3,r/kn lgxyuq8x x.e3i e ;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 up+t8mw4qery z1a.ona nsyy*8m28e 2 an ac series circuit with 12.0 W resistance, 15.0 W inductive ree81 aqnz o8m482pyy2uya+nmswer* t.actance, and 10.0 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 A9-q 7n9 kwrjmiC 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 res+ haxc-9u7c ymistance of 30 W. What is the pmc7hcy u9x +a-ower 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 fop 1v; cxyw) b63a khpg1ox1i1ir a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power supplyv1)kc1oi16 aph; 3y gx1pxwib?

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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 capacitopvr0vxn fb:0/ r and a 15-mH coil in series?x vvnp rf00:/b

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is needed in series with a 4.7-mF capacitor forw-u.j)vpm i p-:fl5xq a resonant frequency of 10 k)uip lw . :mxj5-fv-qpHz?

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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 8qwtu8qi7m ,h49 rz cfseries with a 3.7-mH inductor for a resonant frequencyuq h , 9z47mwrctf8q8i of 1000 Hz?

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142#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor must be placed in series with a 30-W r9/q3fsd6ao gh esistor and a 40-mH coil if the r/ do q3h69sfgaesonant frequency of the circuit is to be 1000 Hz?

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总分:142分 及格:85.2分 时间:不限时
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