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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 except9rrnxqx* ncit( k37+kme,azu0f39c w

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2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction bqdle m1xa1:3 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 loopsys rf.sbkk66 n*/tqn9 e s*)ws of wire in a coil produces what kind of change on the induced6rnke*s *w 6qnsfyks9b.s)t/ $emf$, 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 ramv;/gkw m;1 through a loop of wire produces what kr;v/mmwa;g k 1ind 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 c.l0w/7judfsa hange on the indu/f sd7 l0ju.waced $emf$, 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 magea*p x u+dk/-ma09h kfnetic 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 direcr7:,*b u kbsj cqmp.2ition of an induced current in a conductor will be: br27*kujisbc,p.m q that which 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 ny)t1 cy 6.y5khqrqy;above its center withy5kq. 6 crt;q)yyhn1 y 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 o gr2qybeiq+, bhk*e.2n a horizontal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magnet induces (when viewed yb*ei qk e2b2qgh +.r,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 vectorc9q7mk2 1t xx;*see dg pointsqgmes1*ce7 x92;td xk straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table t;p kycb xp/de3l w0a1.op in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When vp1 .3be0pdwyla/c xk ;iewed 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 thewht*1d o 8ibq .(fdi.c 4upc6n magnetic field points straight down. The magnetic field disappea.h1b*t4n8 ic.q dd(p6ofic uw rs 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 on a ho2s zq j.2jo2dq0wj f2os: wu5c) 5uyw jlyt2r0rizontal table and carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either side of the wire. When viewed from yf2o:2j0j q 5wwy.2qswtlcrd 25su0z2jj )ouabove, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls through a loop of wire with the north pole entering/x* wxax6w mz2 first. As the nort zm/2wax*wx6 xh pole enters the wire, 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 constxo*rz)riv)hn b5 ;+n vant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the o ro;xiz*r vbv)nn5)+hrientation 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 a/zb8);jd 2 clc6-hn mkcr9 ujwa5qn.p t constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points shn- r/8;q)62lnp.ckcj 5ud b9z mwac jtraight 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..ai8 xxz)bv5p
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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 q:d e 5xo9 *8pt.vhcm4ou cxp8that 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 magnetigx 2eo+wq0q zxru8j xe8p3+ l+c 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 tet/e2vch cdlly*)mus) cbd7:* f(ik 6he east-west direction) is moved northward at constant velocity through a magnetic field that points straight down. Mk*f2*hs(eu67/ cy) db:ceil v)cdml take 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 angular velocityq/3elfu kv *j; $\omega$ 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 generator09,n,o:*qvxhwaj tx t transforms

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24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator coil rotates through 60 revolutix-v ws*7sc7eions each second. The frequency of the v-iecs xws77 *$emf$ 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 used tomgf8f2)bl3 -sr8hm it

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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 dehq3n pb db 1vi (/2j5z;vx*ghevice 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 primasnby .,vv3 .ccw 7:kosry coil then it.c7wvks .n :yb 3sv,oc is a

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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the primary coil contains more loops than the secondary :4(odt amk2 fwcoil then it is amtk(dwo4f2: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 5y9h km 3s 6+*dzdmrespower 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 circun)6)1jn .uua;6x:nl6 -igz xaqk )r- ycofbfeit,

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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 be ;*ax s/4yrtseries to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, t yxe r4/ab*s;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 inducto3,gsll7 sh f4or are connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the4,hf l73log ss 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 resistgp/8y2nqb ms-ance 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 conn69 k iyeg5;ouuected 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 seriet;02vgt8qd3 qnnb;jc s to a battery. The time constant for the bgnq tj203;nt8d;qcvcircuit represents the time required for the current to reach

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected ie2** m5;owpt w.zpifgn series to a battery. The battery is suddenly removed from the circuit. The time constant for of the circuit represents the time required for the current *mpiw2*t o.;epgf5 wzto 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 ha o 88mhsju1b38wzuvd5ve the same units except:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connected to an AC power supply. On this circuit, the 5x r8ggy:2m w4gylpzbt ,5kb; 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 fq( mrg5g)omgs c*gqib)w+)+ an AC power supply. In this circuit, the currenfgob mr+gg*5i)cq ) smgqw)(+t

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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 q.r1l7wy se8tby what factor when the frequencw7lyersq1. t 8y 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 acre;nz:mc xf d.*oss an inductor is doubled, the inductive reactance of tz mn :cf.x;*dehat 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 approaches zero, the in kjiz qll2 +j*guo,v3.ductive reactance of that lj.2iguoq3 * vz+kl,j coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In thiwa m,ys7 bj;d3s circuit, the currentbsj,3 a 7;mydw

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance in an ac circuit changes by what factor when t8 +0w+ejpc29ajfgb:o 5 qcoupx-m vw; he frequency is ;2m 9 q0 jeoc+-a: w8uvx jgcowf5bp+ptripled?

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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, thyes1fe:e lm6q) 4w,tqe capacitive reactance of thatmse6 eetf41: lw yqq), 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 ibvp8k-t d 7kghe30fn:(xo7v jnductor and capacitor in a RLC series cir7d:hkjvf p7xkt g3 b8nove(-0cuit?

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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 c9 oq:l+9 jm i*u1df mnze/+dhsre1,z 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. pqewg. xmy7 02xq3q3z The impedance of the circuit increases if R increases. When is this state q.2 mwgxq3zxqye0p 73ment 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 0a r)hfs0uo/a pr0cy2 0rbfq5of 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 increas-q2i0 4w.y*i dd meerxes if $X_C$ increases. When is this statement true?

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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the inductance and the capacitance both g;dm fu+.wo1su :vv*(np 82+et narsg double in an LRC series circuit, the resa; :gto*fmu+v(sr+8wugedp2n1 s .n vonant frequency 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 ay 8n-o ()l bqobvo ezo.x8;+cwn AC applied voltage. At resonance,

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Resonance in a series RLC circuit xc4,goovnl+v 3e0u8ooccurs 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 rotatinxyy6y; -bdhf8g in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are parallel. -fxy;y 6h8ydb

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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 unigwxwb-y5q :y 0lc*b k9form magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the mag-*b5l cbwkw90:yyx g qnetic 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 ra y77;rr z*bi4lvha3jbdius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Findy4 ra3vri 7j;b* hblz7 the magnetic flux 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 area :lu 0m t40 ozc,pxdi1mof 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 chadj 8/ns) (9bkavi: hkxnges 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 fraug5js1e:wu *-va ,nm:t*o bswme with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 5-mnbg1, stueu**:o js:wawv 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 awb,h80c6 vl i wnpac z*w+b1u)n 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 ands2q9v:fs74 gup)v -su8utgfw 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 om s+e76cs l.x*by+ sns1n2eo the downward compone*+emeb+s nsylc6n1 os.7x2 osnt 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 ro3w:v:03ilpw lv0f-mxeuqf 0j tates at a constant angular velocity of 2.0 rad/s about a verticalw q0v-3:wpfxv: u3mj fl0ei0l 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 .zb dee6lx(6h/f0xe kand a cross-sectional area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists uoca; l/pt 2s0tb7kx( 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 armaturw0mc l )*:tocre. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1 c*l)0wtrcmo:200 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 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 o ;bycekx:3xb2 f 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 simjzn)an-5j ws+ ple AC generator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T isja5 +jn nzsw)- available. If the area of the rotating coil is $100 \; cm^{2}$, how many turns are needed?

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70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are designing a generator wit-bxie(gmky/hp ;;fl yo8x5 7 t ksok90h a maximum $emf$ of 8.0 V. If the generator coil has 200 turns and a cross-sectional area of $0.030 \; m^{2}$, what would be the frequency of the generator in a magnetic field of 0.030 T?

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71#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have a resistance of 6.00 W. Thefpoga0 ,72n0; nc4tgzvq9/ br,g q 5bikx wpp6 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. Th42v:w0 6jr ii dquh4xp1lf /qve motor operates on 120 V ri :0vl 6idjp4/qx1w 4fuvhq2 AC, and when running at full speed it generates a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resli0 3wq;qr* teistance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A. What is the sti3 l w*rqt0;qeart-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 r)wmn /u.ii r3uesistance 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A .3ui u/mr)nwi 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 ae0xt( r dk2(hmwdz- 0 fuqh91W is connected to a 24-V power supply. The ope2whrk q91d0u(d-fxem th az0 (rating current is 1.0 A at full speed. What is the back $emf$ when the motor is running at half speed?

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76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A step-down transformer is needed to reduce a primary 1jf8.i g s.qkk84juu fzpbt. yr9h/f6 voltage of $120 \; V$ AC to $6.0 \; V$ AC. What turns ratio is required?

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77#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  2.0 A in the 100-turn primary of a transformer causes 1 ukjlow *bn+pw2ca,y3nl *v414 A to flow in the secondarwca3n lpk*y ul vjb1n*w,+o42y. How many 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 primary if the 24-V s2f;1do;*q z7 p8e5 iebo udmrgecondary ;2 1;qzu 8og ddomf iree7bp*5has 100 turns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consists of a 500-turn primary coil and a 20:m8bank8 7ac m00-turn secondary coil. If the current in the sec:k a bmma887ncondary is 3.0 A, what is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primvh9 1,f ,pnzljuxhq9 2ary of a transformer. Assuming 100% efficiency, how many amps at 24 V can flow uhn z1jqh9x ,pl 2,v9fin 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 tra64p8xbbhb52 wc)d cvp) f*jwfnsformer provides 7500 V at 10.0 mA. The primary coil operates on 12h6xvb5pf)jbf wp* b42cwc d8) 0 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 60r(:/ m upxg1si turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is present in im:rs 1up g/(xthe 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 on6d04vm.) *jeegh*ng 4lmv cey*1 w enh its primary coil and 300 turns on its secondary e**vg6d1we 0cmvnjn4e *ehy4m gl).h coil. If 120 V at 2.0 A is applied to the primary, 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 turnry oh50n*j vxo5:eh:h s and its secondary has 200 turns. If the input current at the primary is 100 A, we can expreh h 5n: oohy:*xjv05ect 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 turnswwb+1 ,;f 91id kw 0rlodozl0l and its secondary has 200 turns. If the input voltage to the primary is 100 V, we can expect the output voltage of the secondary to 0dwlr +11;dz ill fo0bko9ww,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 turn*6gku l /zu0tis and its secondary has 200 turns. If the power inpk0 t/ilgz6*u uut to the 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 Ax3) (8*(yc bvmwwcx ox of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Fiwc(yb(c*xm xv 3ox )8wnd 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 voltefm47xz z 4 .aqj6xy:sage is usually 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 transmissia4f.q jzx6: mze7s x4yon 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 v7b)whtqih4q i fvp(k f*fa/( :oltage is usually stepped up to 4500 V by a transformer and tran*kfq/qv fthafiih4) :p(bw7( smitted 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 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 tok7t*h2xq-n y s+xe/l/g jevo0tal resistance of 0.60 W. A generator produces 100 V at 70 A. v7h-e n+k/ qj/yg2x leo*ts0xIn 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 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 resistancez, y(h np91p2 t0jef sc*1mwax of 0.60 W. A generator produces 100 V at 70 A. In order to reduceys2ppx1a0ft1,9jn*cw(zm h e energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W lin fln):eg- qy2ye at 1000 V. How much less power would be lost if the power were transmittedenyfyl2q )g :- 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. It2x /kqgz hbv 3inm4tyi6vji* 0(d/ew8 is to be transmitted on a line w/mit8nbw devgyk/z0* ij x3qhi6( 24 vith 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?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. How much energy is stored e da:vu.1jnt3 in the coil's magnet1.u jtnved:3a ic 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 rei*z y**k xrot 3tlsq86sistor and an 18-H inductor. What is this circuit's time conss 36y* ti kqrto8z**lxtant?

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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 rms voltage i( uyccr9.al;ilstt4 tn64 ,a ds 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 Aio8w+ bja +j to51k*eyC 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 bbvn4(zp 40ycresistance of the lamp?bb(nvz0c 4 4py

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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 conne)i(zngk/1r 3hcbpz /e cted to a 120-V ac power supply. What is the peak current throug//z) b kzp( rhi31cnegh 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 tonz7; d.:gh5ch,vghaz a 120-V ac power supply. What is the power dissipated h, g. h :nzh5vc;zdg7ain 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 res:-umvw * p84ftkvqo839yw aut-8nw( kcof+ nmistor is $I = 0.80 \sin (240 t)$. What is the rms current?

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102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W res:pl tx+c20 ok1 ift;.: bwm yv-kt.wmsistor 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 50e/co5x yq 6emhi*f(4e rul q1/-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 z5v 7;nbv( uld60 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 g3,ehq ;te5g :j;.1 v5 sdg hi 1v*tzpmt-axsiat 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 indufqx-em2 b6nh-d-e 7jl ctive 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 10wt0 7wbw1 j2ad00 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 h ) rz52t(/qytu)(eyec0sggainductor when 120 V AC at a frequency of 20 kHz is app a2cqse0gu( h )yt(ge5)tzr y/lied 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, 2.ojcxk1ftzuunx t e0w75md+k /s9:u60.0 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 a+9c)m u fk(qe p4ewi)ht 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 neede)+f gs 4r7ih :83kc)c6yx zcl tf)onnfd to 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-mcg5zp(ndoa8u a+h hq9o t5;1uc2xc s-F capacitor 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 the capacitive reactance ox)hag 5y (esoi+sj*gkyer (14f a 0.010-mF capacitor be 100 W?jeyg+5x1s*ihako e() (y4sg r

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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-m2 e zwsx4c9rt-F 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 resi:sd -)shsq ,oistance, 15.0 W inductive react ds,-so) iq:shance, 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 rescaf4saz w+9 .distor, 20-mH coil, and 1.0-mF capacitor are connecteaw c +azsd.f49d 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, ln,+d k. wf)tp20-mH coil, and 1.0-mF capacitor are connected i,npfw.) + lkdtn 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 inductor, what is thewlj3ku- ymv/ frd 0+3i impedance at dyr3i mk-l+vf j3w 0/u1000 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 jxv:3 wq ub1xc p0oqgc :ssq,o(e5+4bis connected in series with a 20-mH inductor, what is the phase angle at xb,(o0o sqqq p4 gb3v:cw+:s j1cxe 5u1000 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 serietw*, 6 46n kz1cuu1gezcf goqk2. jt)js circuit with a 20-mH coil and 1.0-mF capacitor for a toto1g*j1 k,ucztw jquzc.)t26 fg e kn64al 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 )z fvt -b 40 (nb0yjyh 0oal6;rs/hurgcapacitances is needed in series with a 100-W resistor and 15-mH coil to get a total impedance of 110 W a6zf(b y;tr0 b0a/vsl4ru0ng y )oj- hht 2000 Hz?

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122#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance must be put in series with a 450-mH inductor at 6-;xvtbksuub(8g f r; 5000 Hz for a total impeuxftg6s ;-bk u(;vb8r dance 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 withms .3hjytq2t /kpm+z( a 100-kW resistor at 1.0-MHz for a tot(.qhj3 ks m2+/tztpmyal impedance of 150 kW?

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124#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected in series with a 20-mF capacitor. What is the imp5 08:zhfex cmhedance at hf 0chze: 5mx81000 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 c51 md*n xkwyl+ge6uh+ m0*dckd0 ;e hxapacitor at 1.0 kHz for a total impedance of 45 W?hc+n5x;*ulmd yde 01 wk 06+mxedgk*h

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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 with a 10-mF capacitor at 1.0 kHz for 0zk dy+(fm;cadyr5g9 a phase angle ody90 5ym;rac+ fzgd (kf $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is neededi0 v;5xzm:xsk4pl 9sr in series with a 30-W resistor at 1.0 kHz for a total impedancepi:sx 5v4zsk9 lx 0r;m of 45 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 1r xj5irzw7m51 09yh/dj1 p uhv20 Hz. What is the phaw5y0h xz j1mv/h9pj r7rud5 1ise 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 resikx8rv)1ci xbr-z.pg1stor, 20-mH coil, and 1.0-mF capaxcz)1-.v8i 1bpgr xkrcitor 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 wr)e22a bh;lz )rv:w9kr1z xucapacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz po)rkz2zew)rh:bl91x;u2 vra wwer 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 inducto- bau-1cag0 h;duipp8r of inductive reactance 30 W are c-dh 8ai cu u;0p1-abgponnected 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 za2 2hx;(,haoghs7*p 9d3ywa84 5dsprck mzla series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, l ,93z;rg *ywx 4m dzpad(s2 75co2k8hsapah hwhen connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W resistor for l5 ztck+pb6*p a phase angle oklpzb56+*tpc f $40^{\circ}$ 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,;qg 46sost zspj567- ht )kuib C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferred from the driving soh)j tz u5osb7g t6 4pq6;-kissurce?

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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 resistawzzk a:e+d:9( 6fqt0 a dpqi2unce, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-Vzeu ik(9d2p6q: wfz+t a:d0aq 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 swht3+nw22 ,wjt ,b86 f5rvr(n chwelis $63^{\circ}$. What is the power factor?

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137#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ac series circuit has an impedance of 60 W and a resistance of 30 W. mv 5m +k /e*uo r7xws1nl-z/dlWhat is the powl+ e/ m1wm5o7 xd-vnurs*z /lker 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 containing a 50-W resist))nsww/0aixi-ul*k76mubxw 1 z zmy .or, a 10-mF capacitor, and a 0.457ximb0w/ u syx-16z muiz .n)alwk)*w-H inductor, when connected to a 60-Hz power supply?

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139#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the resonant frequency of a 1.0-mF ca 6zuu o+sa4zo9pacitor and a 15-mH coil in series?+so 4uo6uaz 9z

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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 forud1 :tcywf-pfn5;( hk a resonant frequency of 10 kHz?wfk1nt(fh; :y d-cp u5

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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;-j7gk9;z j gkgjpz2 y with a 3.7-mH inductor for a resonant frequkj2 jkg7gpy9 ;zj; zg-ency 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 resistor and a 40-mH co+0f ayko(8 9:le nfq5efex4tv il if the resonant frequency of the circutve:4 f k+fenaqfo yl0 xe9(85it is to be 1000 Hz?

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