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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 unitsa 7jxfbow)0p+ 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 indukr)l :ujwhhkm4946 xr ction 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 a coil produceqgtg8)k30+rbi b/6*j ax4h fzxy-sty s what kind of change on the i3brby ts*gztj)6+ i g 4y8k 0xh-/faxqnduced $emf$, 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 wire pgfdp )i l+7 h-bfh:- v1sx8lhfroduces what kind of change onbfdhg xhh+- 8:-i)p1ls f 7fvl 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 on the in s/o)o;d 9fe e6lsqx+j 3ql0h*af1fk hduced)1f fxhselk q +j;*6seo3d/o 9 q0lfha $emf$, assuming all other factors remain constant?

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6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As a coil is removed from a magnetic f).n+d xqln,-i ,bo gemield an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's law, the direction of an induced current iniiqvktb8nk5gyzq;0 z4ru,-ch(n:3e :-t avm a conductor will be that whic yk0,zqvr ut n:5(g 3-izcq8b:;t n4-mvhkia eh 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 flat085qq h1erzmp3 p-i utopb4 gm(ol7- t on a horizontal table. A bar magnet is held above its centerp 4p8lobt-eguqrpm-z37m1qh5oi( t0 with 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 e9(c3mm x/s wbs;k2c3:pq 3 mc5vijuomagnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the fall/ckuc3pe259 3sm; jvci3xmbow(q s:m ing magnet induces (when viewed from above)

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10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a table top in a region where the magnetic field veozdps*/t 9i v1a q/nw6cx ;zl5ctor points straight up. The mnv5c*;topizd6 sqx91a//z wl agnetic 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 topls* c(f7/r egl in a region where the magnetic field vector points straight up. The magnetic fi ( /s*rllgce7feld suddenly grows stronger. When viewed from above, what is the direction of the induced current in this coil as the field increases?

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12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a horizontal table top in a region where mni34lq4pm )et(xw.4z pr,z othe magnetic field points straight down. The mag,p nz4p4 e4 )m xlqoz3rwm(.tinetic field disappears suddenly. When viewed from above, what is the direction of the induced current in this coil as the field disappears?

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A long straight wire lies on a horizontal table and carries an ever-i o5itknu. ,k9ancreasing current northward. Two coils of wire lie flat on the table, oni5.u tonk9,ka e 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 wire with the north pole enterinwpd(r95 bblt 9jn0z *sg first. As the north pole enters the wire, the induced current will be wj9t b0rnbpdsl9 z5*((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 angularow :qck mmwh/0 y4,v4zco:c4knru1d . speed about an axis whose direction can be varied. In ayd1rm:cu0 ,c/k w4m w nq.zvho: 4o4ck 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 consf*t*ywxcc4e. 4-lm h z t(aq2xtant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis4zhc xl4ta .2e- * qmcxyft(*w 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.asc s0b jteeb0 ,uje,24o rb/9
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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 th7i ohvr,4ln n+at 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 m p04zzse:t 5v:esv b/l7n 8pwragnetic 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).d9ak 7eho 2kn is moved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potential induced across the rkeh 2na.kdo7 9od.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar rotates at a con 8v0);8kn-njsm djoqhstant angular velocity $\omega$ about a vertical axis through one of its ends while in a constant magnetic field B that is directed down. The $emf$ induced between the two ends of the bar is

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23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An electric generator t 8.)jg 4qgojahransforms

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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 secondq xiys*1slm- 0uv*:pl . The frequency of tysi ll**p- 0:sumq 1xvhe $emf$ 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 devg kt 9 o ts6*/qbadqam+j;g9;gice 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 8g,g g/n3 yb2d6bgae oz5p)cb 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 tp ,*jkwbly7az m7 2ae-v qe5t:zav5+x he primary coil t77-yzpwtj5zkb2 e*m+ l5 vaea,vq ax: hen 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 prbcwzil:) d 89dimary coil contains more loops than the secondary coil then it i9i8l b:)w cdzds 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 inpuy t90 ik/jxn;g,fv(wjt

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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 resonantwza/+(x mt1 haje66 qq circuit,

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in seri .hmcyhhdq h*2-az+wj*+ ce 4fes to an ideal battery of constant terminal voltage. At the moment contaw- yhchz* .++hedf *jc2hm 4aqct 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 inb2/chf, p( our series to an ideal battery of constant terminal voltage. At the moment conbo/uhp (,f2cr tact 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 inductanq rv /tkzs,23wce L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the inductance is 2L. When it is connected to the same $emf$, what will be the final value of the current?

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is hbp5l,c wp7ht1 6cnbv /7s:up connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a battery. Tr) fzm o92kof0v*xcu8b .l1 ghhe time constant for the circuit represg 2l)fu.8oro1xk*b 9zhcv fm0ents 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 inductgi:yc 2ko,1 jma48 oator are connected in series to a battery. The battery is suddenly remo jk4a,:ci81o2t gyma oved from the circuit. The time constant for of the circuit represents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following havq3 oh edsy;j53 8c.ncce 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 vpra) 96 a9zoxju(mn2yc2z h;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 connecteddh7tc-+4s bqy to an AC power supply. In this circuit, the currenytq-sh7b d4+ct

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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 wh) 8f ajcqo54ub;rxy/oat factor when the frequency is trj;cqr xa8by 5/fo)4ouipled?

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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 doubled, the inc,s+dl6 zf1 enductive reactance of tfs1edl,z +6nchat 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, t jv4e32rtm+bmc7.t k5bea ls:he inducc2bl3ae75s:tmmr .jtbe +vk4 tive reactance of that coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected th7*l +q3;wg0uw puophui y+v*o an AC power supply. In this circuit, the current+l0 wpguw+p;hh o uivu**q73y

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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 v p+xqc1 caol4hq+)xr,b k*n3 factor when the frequency is trc3h vx *r apc)q4xkn,bl+qo+1ipled?

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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 acr4y: 7ql)h;iumgjk8qw oss a capacitor approaches zero, the capacitiveml): w4yuqgkj8 7;q hi 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 m (p jgw8f4lhs*xis6 ,m*0 md1sf9pvkthe voltages of the inductor and capacitor in a 0** dl g jskp s (mwxhfm69im4,vs18pfRLC series 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 RLCu mb.ntxj 9tcpan.3m.r hx+1mj(+5ou 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 of the circuit increases if R 84e06puiaq+ v4ww :ra zeng qz/8 :uhr/cd0qj increases. When is tvwpa6+e nq:8zi40q: raq0 u /hgcj u8dw /4rezhis 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 circuit increasecpb7vm8i,,moy v *w0os 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 circd(+ub6c k1rk euit increases if $X_C$ increases. When is this statement true?

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51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the inductance and the capacitance both double in an LRC setc y*i u: pkdlctk5t1b *79a6tries circuit, the resonant frequency of that c*pk lttyt a9k tu 5dc:*b7c16iircuit 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 t 19;t:xqc +rit-wgq *x mb6dsbhat is driven by an AC applied voltage. At resonance,

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Resonance in a series RLC circuit rcxf )n/x)cvh07cp2nn+xs-k occurs when

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54#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A flux of $4.0 \times 10^{-5} \; Wb$ is maintained through a coil for 0.50 s. What $emf$ is induced in this coil by this flux?

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic field of 0.2vg 5d68 cp1dnu5vt:s n0 Tdp ntug655v :ncsd1v 8. 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 7x04 qxwp4sxvis rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of thqxw4vspxx7 40 e 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 i n.i(rmffr:t5 b 0werd3 eok:6s rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are at an an6m(t:re . e dfiw:on0k fr3br5gle of $30^{\circ}$.

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional area of an adjustajxcgv9gi2; 4 ,ymb3bd9-v4iwnwf ;f jble 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 from 1*l( szrkqr 7m8y85h,hvv xhz$4.0 \times 10^{-5} \; Wb$ 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 20)nn d*i src4-h0 turns 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 d4nni)r csh *-0.50 T to 0 in 8.0 s, find the average value of the induced $emf$.

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61#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A square coil of wire with 15 turns and an area xf r3)a/bi)rudf ) -erof $0.40 \; m^{2}$ 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 an/pvv-ia wiw t0id3w ks.c4; c2d 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 thenzqg kqp2+v co6lr495 v2czpg5r4l k9on6q+qdownward component of the Earth's magnetic field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar that is 2.0 7 dubgs930qvt sb*zdm7iqa6rk f238bm long rotates at a constant angular velocity of 2.0 rad/s about a vq2sd7rfauzg 3 v36b8ibb0 q7* 9tdmksertical 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-sectioiej /grj/9/frj9z)a onal 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 x xb qg h;nlj:ka4)x+w,rtnx 04m n,l(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 itrrt8c/+w /sits 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 rotation, wht/ r/rc8 iwts+at 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 100b)l/op4m+ pfo 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 constr l3/v0 x*vmws (c:jrsyk7w xz9de*a1juct a simple AC generator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 7ej9xv3yask0cd*v x1s(:rmjl z ww*/0.050 T is available. If the area of the rotating coil is $100 \; cm^{2}$, how many turns are needed?

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70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are designing a generator with a madp6g8i,5qkwjf ( kg +fi(cn.hximum $emf$ 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. Thx- 5: re klvgizjn:5 5f0olne6e 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 mtw118z (ex cigotor operates on 120 V AC, and when running at full speed it gen zex1(8gtiw c1erates 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 conne,a*qh t1k i;72cnow ,jy ar;n hty0(wpcted to a 24-V power supply. The operating currentr t,nk*yyhtph7ow0cwaqin;j(a 1 ; ,2 is 1.0 A. What is the start-up current?

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74#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V power supply. Thf*l1 wg8rum76 ekcd 6c-nlql5e kl-lqmf g 8elrd6n 5wc1*6u7c 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 24-js5cfxwru8 3jivf9 /d x zub*(+ 0ie*aV power supply. The operating current iv *9xj re ucdfujxi350( / ab8sfz+i*ws 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 owovwit2a;m8luno ;p, q6 2dsbwv/29primary 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 tran7tha s8lk ej*3dg cvfi6 bq63:sformer causes 14 A to flow in the secondary. How many turns are in *3qb:l78dh ceskg63tjaf6vi 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:n qw7 9ml8vwuqdh(4c are necessary in a 110-V primary if the 24-V secondary has 100 turmw qvdq: h9n l(74wuc8ns?

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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 2000-turn secon cz+o;j.7kidx dary coil. If the current .izko;+xj7 c din the secondary 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 primary of a transformer. Assuming 100% efficieij+5xm 8fm 7juncy, how maj5j m+x 8u7mifny amps at 24 V can flow in the secondary?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The secondary coil of a neon sign tgou fxjvd. b i 3y(vk*-s:c4,bransformer provides 7500 V at 10.0 mA. The primary coil operates on 120 V. What does the primarv 4yo(x3fi.* d-gu,jvb:cbks y 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 i-(tcsbn: tq+g ts primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to tq+g- t c(sn:bthe primary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coil and 300 ture3le; 6k*zt4 k2lplh mns on its secondary coi4ll*; zpm326 ek htklel. 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 turns and its sepo .o2 ynnvs f99 rjve/el070ccondary has 200 turns. If the input current at the primary is f 9evoejc2s0.l0 97onprv yn /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 transformer06wnjbakj 2 :x has 100 turns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we can x j:n ab0kwj26expect 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 t 0 yvf2(gq 9bhr4/ ocwefg:9seurns. If the power input to the primary cs h 9:4 w(feeqb9fgrgvo0/y2is 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 ) q3dsysjb ;:g60 A 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. Find the number of turns in the secondary if the primary has 200bjds 3;y)q s:g 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 stepped u54ke oh 1x+10 nr+xst1d8z8wi;nraycm n;d qdp to 4500 V by a transformer and transmitted through a power line of total rekn4 8;;sd1z+t dx0+noi8 ew a11hr5 nqxy cdmrsistance 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 1/p0ln( -q xijh20 V. The voltage is usually stepped up to 4500 V by a transformer and tn0jhl/i-(qx pransmitted 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 total resistance of 0.60;t fh*rsmb/y 8 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, tsbm;*8tyhr/f he 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 resistance6+sdzgld2pe2;; r zp+rd9hay 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.hd;ga9pl6 ;d2s2e+d +zrzy pr 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 mu5 bjyxsl)nghrg4 2jm.a )zb,yq //1qf ch less power would be lost if the po ljmq4z)b)1fs/qx,.ag5 hgrj yy2 /n bwer were 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 b88s xppc4tc 4oe transmitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a transformer if the power loss in transmissio4posx8c 48cp tn 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. Hown1uxxy3y0,-d5yeja k much energy is stored in the coil's magn,kxny1yux5-y3ad0 e jetic 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 whot 1;5)fsxg tiq 9ibm-h .mf4s/mc.this circuit's ti q519scihg.f ot stbxh-.m i ;wm/)4mfme constant?

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96#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the peak voltage in an AC circuit where the rms voltag2s6p4w+nuaev e 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 pe-fdbdnt0 5- *g:)xd wsbuap/yak 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 resist6ey6dapkno 7bg5uq 59ance of the lamp6aebuo5g 5qn79 y6pkd ?

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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. What is the peak cure,db1v.n(vrqhqt-o, v y, zg/rentq e.vyzr1vnvg(/, d-, oqth ,b through the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. vw)2zzk i6gi 6*; )m6e. dbunk5ytr7bd(j mnxWhat is the power dissipated in the resisto)6d j6iv )5 dz(kx2 mi7rgwb. tuy6;n*nebzkmr?

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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 i.8 fe-ioq,f0ug+1b 7j uzzrqns $I = 0.80 \sin (240 t)$. What is the rms current?

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102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor isnx,wq sy ilr6g/h) g69 $I = 0.80 \sin (240 t)$. At what frequency does the current vary?

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103#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor dmy 9z/fs6zt, 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 a go (10-m w xt.g;ddel,cyuxycx +;kj;n 5v1kdt 60 Hz?

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105#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the inductive reactance of a 2.50r5d)o5z84f3 agevfrjb vt* ,p-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 inductive reactshb/ - avd 8x n qv) shnf84z,.l-+*tzzgbiad9ance?

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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 reactancewq - tjgsj;3je7)i+yq at 1000 Hz?

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108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH inductor when 120 V AC at a frequency of 20 kHzu62qvr5y)mlix79 /wnb c +obh is applier2+biuv)m n q 5wxb7c/69h ylod 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 eze0,p* )tmok 110-V, 60.0 Hz source?

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110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitive reactance h tpzdyd8a s0.n0b k*h-k:dn )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 (jemz9kd4jjd w;n+y9 x*sh9xuq: 2bu 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 reab: okoo+ ji3kq1z0ut45vt1 r zctance 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 reactan z:sj8z8ry)f9gyx( ng ce of a 0.010-mF capacitor be 100 W?sy:gzf nj 8)xyg8r 9(z

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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 10hyh9*z6 syc7r:z qmfx re)b .600 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 7mom7*bmdb zmih pa1j57 t9u (with 12.0 W resistance, 15.0 W inductive reactance, ap*a7t9mbb o1mim( jm7h 5d7uz nd 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 resu mv -qh51hjo-istor, 20-mH coil, and 1.0-mF capacitor vhu-q oj5hm1-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 15 j5eb6nvn0/n,gfer a /00 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor a/n/jve0 gn,re6ab5nf re 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 inductor, wph tg.;l 8bioo7 ztu42r m4zc.hat is the impedan2 8ig4 toh4plrum b7c; tozz..ce at 1000 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-mH inductor, what is thh:u45vegv x7 1ywm5l6: wdiy pe px u7w y :whigp:651dvl5vy4 mehase angle at 1000 Hz?

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120#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in a series circuit with a 20-mH coil and 1.0;-t+g 30y:shmy/+tk9kfmvh zp d c 7qk-mF capacitor htyms v:hkk/ +t;+7d0p3m9 z fc qkgy-for a total impedance of 100 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances i)+re t/7zns kjs needed in series with a 100-W resistor and) k/e ntzsj7+r 15-mH coil to get 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 at 5ji m;)a2n l(nm4m skz:000 Hz for a total impedance of s(:k)m2nzamjml ;ni440000 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 1.0-MHz for zqdg f f*hm.4d 0mj7j(a total impedance of 15fj dgm7q*f 0mj(.zh d40 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 wzw.sr x.q6 bcl1qw12j ith a 20-mF capacitor. What is the impedq . wwlcz2x 6jqsr1b1.ance 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 nee kr;hm2v -bdc 0g3ps)ided in series with a 10-mF capacitor at 1.0 kHz for a total imp-g v3pk 02shr;micb)dedance 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 neede-ei r1yb 03xq,zousw ,d in series with a 10-mF capacitor at 1.0 kHz for a phasewzr 13o,-usb,xey 0qi angle 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 ne(tt, ws 7*s*i3 f4ybrfkxqu0jkim t9) eded in series with a 30-W resistor at 1.0 kHz for a total impedance of 45 Wtqkt*4fm,y9*rbti siu jxs) 7k30fw (?

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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 sjbst;zilu :)l5 o. 2ddh wla6ezoc 8xc6f96 i0eries with a 100-mF capacitor at 120 Hz. What is the phasz56t c )8o: xdl6ce bw 2lsh0uodi;6fzljia.9e 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 resistouw w*bp +h/:ez(4z fblr, 20-mH coil, and 1.0-mF capacitor are connected in seril/zfu h*be4pwzb+: w(es?

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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 vsy utn49+sq6j n/( wra 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected toqv 4u/yn+6tn 9srjsw( 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 n0fie:ny: 6 wpvsiw-o:yxx(/ an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz power source. What current flows in this cnswpf-o x:/iwxy6(yei0 v :n: ircuit?

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132#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle for a series RLC circuit containing a 50-W resistoruav24:(v 1f*ch tqn 72wisq hf, a 10-mF capacitor, and a 0.45-H q:ic v hf fa4u*v12q2ht(s7wn 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 with a 5se()ch5ko7 bky qt, rvcse67 qk+7ql,00-W resistor for a phase angle ofchk sqc+ ( s),q75kerv,6b7q klyot 7e $40^{\circ}$ 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 frequencoca88+ aa +cuty should the circuit be driven in order to have maximum power transferred from thet a o88cauc++a driving source?

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135#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power output in an ac series circuit with 12.0 W resistance, 15.fk;.2mxqz(j.h jb t1q0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power su zqxjh(2fk jmq1.t.; bpply?

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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 ni(otay0 pgtxk*yj+:wlw6 -5j0 vcr 6 AC circuit is $63^{\circ}$. What is the power factor?

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137#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ac series circuit has an impedance of +70wj,k 8tud 9ybqtet60 W and a resistance of 30 W. What is the power fa0wj tk,td 9t 78eqb+yuctor?

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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 c:d5 5 u7rq;lln 2dhfbq7ib u(9m fpip-ircuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductoi-p: i975 fduq(dmbp7 qrn llf2 ;ubh5r, 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 capacitor and a 15-mH binq.:k+ ) 6icvn2gw bcoil in series?g2 bcnbni qk.w) :vi6+

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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 inu65b p:u 6.v /z+.rv ,ls/h;xo qcx7pikexm fn series with a 4.7-mF capacitor for a resonant frequency of xqi75l/sbpv.z c/.hxkx; m,ve6 p:fo +6uunr10 kHz?

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141#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 3.7-mH induck *dk(1 7 pb s6*pxvop 2gf4go*vc+cvktor for a resonant frequency of 1000 *fbg 2 4popsc*7kv co+x1*6pvvkkg d (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 bnxxs2usv/ af -z t0t,.e placed in series with a 30-W resistor and a 40-mH coil if the resonant frequency of the circuit is to be 1000 azx t0nf 2us .t-sxv,/Hz?

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