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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 o- apgqziz59(,pi -n4,rurf xa f 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 inducfx7q j:77t ostb+* zdrlz-2lction 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 produces what kind of 7,ceu9 y,+c7pegrkv- afdy 4 -/gxyp ichange on the p77 kdu4,,9eycvggiy+-fe a r/ yxc-pinduced $emf$, 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 wirvz8-xco :tsjonu* n,/ w4d q)qe produces what kind of change on the s*w - ,cx8u):qnjto/ zdn oq4vinduced $emf$, 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 produh5febl0e p .is4m v5y+ces what kind of change on the induced lv.m5ps5e+eh0biy f4$emf$, 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 me2d v)nq 9ksy )klz9g)bzda2-agnetic field an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's law, the direction of anmlkhs77 u (g:xaz6 ezr/.hp7 v induced current in a conductor will be that which tends to produce whhxr. 7v6(z:7 mhgae/lk 7suzpich 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 tabpop01 d 3knf 7yiice7xx5p))cle. A bar magnet is held above its center with its north pole pointing down. T 7pf)71c3 i0d)5ko pncx xiypehe 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 magnettu 98nrn*sn :5wy ,rbkpluf) / is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magnet induces (whe,b8n5sup* r /lrtynw9nf) k:un 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 vector p z+3yo+xstfm:ke3z u:1c v o7voints straight up. The magnetic field vanishes sudzs:m3ot1+f +yvekc7 zo3: v xudenly. When viewed from above, what is the sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top in a region wheyf zrxu+kh,*( re the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above *,xzfu y(rh+k, 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 ho8 i1o onr*cl9prizontal table top in a region where the magnetic field points straight down. The mag*c ilo9op 8r1nnetic 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 a6j; j8w m)okfj asrf5-nd carries an ever-increasing current northward. Two coils 5)fo8s w;jjmrf- 6jak of wire lie flat on the table, one on either side of the wire. When viewed from above, the induced current circles

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14#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A bar magnet falls through a loop of wire with the north pocfv:3 phipr dy 7m(3px+ ,q,bnle entering first. As the north pole enter pmxd7y3h ,n3qp(:vbrifc p+,s 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 cons wy+3o eyq7b3ctant angular speed about an axis whose direction can be variedbe+oyw3 7cyq 3. 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 7 w-4voo )2rtpe uus5tis rotated at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points strae )2 ot-u7swto4uvpr5 ight 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.x iu66- jpngiylzi:7i1(5m mi
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18#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Lenz's law.
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19#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
List the three ways that an q3(0 xa fm5zy3x etw4a$emf$ 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 magy2 6l *k l3omliu7oh8vnetic 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 w (pjiy(cp8tu 7-p*goin the east-west direction) is moved northward at constant velocity through a magnetic field that poin7u w*8 gp-p( i(opcjytts straight down. Make a statement concerning the potential induced across the rod.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal ba; -vlq8jso2e ar rotates at a constant 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 transfc,xbpax-89hvhrza / , - r7vidorms

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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 thw bav 6yu/4/yi 6qqy8utq b+tz2s6mf4rough 60 revolutions each second. The frequency of th 6bt 6q +8t/v/im6yzuy 2q ab4fws4uyqe $emf$ 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 devi0nf3 br7 +(rjjasac k ,c)+wtkce 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 devi.l1 vqlzx dth.2bmx 91 j wyqs piddtu)/6r43(ce 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 5x5 e:qqz07 e1m14za vqfzh *n+obcnzloops than the primary coil z:z* +5m4qo5vf behaq 0 n1zecq7 1xnzthen it is a

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28#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the primary coil contains more loops than the secondavh( 9tco-xr3 s ufb91ary coil then it is(vo1sfu9 3h-r bxa ct9 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, th.vi6+yf7wqc6g rz8 ou5z8irte power input

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30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a given LC resonant circuit,337*r b reu7kw.4 kwu za8qnfh

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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 connect 8uh r64rpa+qnbi:*c ked in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the voltage across the resir846 ur*pi:n ck+aq hbstor 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 t34ia c5xz0oz( syr b4ko an ideal battery of constant terminal voltage. At the moment contact is made with thck(3 5y z 40sbox4zarie 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 resistance R is connec pz z;srxi 9hlrl:u.x3 hvu7+9ted 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 yjwu og*/ ar91L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connectedw:yceti5x,o,c ls u+) in series to a battery. The time constant for the circuit represents the time re x)l oiuy,,we+5cs:ctquired 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 induv,m inc4t3c9c pga . bzb-6l )orw6zx:ctor are connected in series to a battery. The battery is suddenly removed from the circui66 z) 4l bo:,3 c-txmv.iwgarpn9 bzcct. The time constant for of the circuit represents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the same units exceew*igime* / (fel,s2/w/- h qvfzsa) lpt:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connectekt 7c,p3itb n2c w:4 aswt0,qkd to 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 connecte4 (x9,8 flebd8qvyuyb d to an AC power supply. In this circuit, the currenyev,q48x( l89u ybdbft

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40#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The inductive reactance in an ac circuit changes by what factor when the frequetr g vx a492kofw;h8b:ncy is tripl g9;h8bvrxwk4ot : 2faed?

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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 thehgmtj4 isq)0j u ,bu-8 AC voltage across an inductor is doubled, the inductive reactance ojus hti8)4gbmj ,-q 0uf that inductor

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across an ingwcs.1 pfxt:;paw a 27i mu5+xductor approaches zero, the inductive reactance of x+ wxp1gaa.u2ptf7cmw; is5: 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 to an AC power s azk 6njl/rdbf72r+b6 upply. In this circuit, the currezn/+ f62br 6 jlarbkd7nt

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance inzh af o6lu (a e+vha9+.vhou.,ih r2iu25ct v( an ac circuit changes by what factor when the frequency is tri (rco h+a itavh z+96.leu ,v2uho2hua fvi.5(pled?

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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 thq05;6p2f aov qndz v0je AC voltage across a capacitor approaches zero, the capacitive reactance of that capacitf;5vq0zpo2 6qnavj0d or

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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 d3 t.wy0/)zeym :haewvoltages of the inductor and capacitor in a dzayw) h:e wy 3/tm.e0RLC 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 RLC circuit is defined as ni2d mlqjqxbt+:v:. y qn(t*w3ey.+m $\cos M = R/Z$, 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 inc gd.ysi7 s;-b2m* gttydx6o2lreases if R increases. When is this statemenbds *dyt7-oy6tg sxl m2;2ig .t 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. Tmf *rxm vig-s)+kk5w0fk.y6 vhe impedance of the circuit increases if $X_L$ increases. When is this statement true?

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50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC series circuit. The impedance of the circuit increases eyq.dutyu2 oqs/:zr y.5ki55 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 capacitadwy+ 0;d oc 7gg:6b;npo gm8hunce both double in an LRC series circuit, the reson my+nw 7p udgh;:0dc;gb8go6oant 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 a2u h0n,.zv6*e *jg , gt:wb kmynjslv/n 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 RLhx8*9 jx*;bb1j yngk2j q b0oyC circuit occurs when

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

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a unifokjytk6 m9 f8 nsejx4(.rm magnetic field of 0.20 T. Find the magnetic flux through 9sj.kjy f48mnke 6xt(the loop when the plane of the loop and the magnetic field vector are parallel.

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is qiqj /,/7d5 lj evehd4rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loo /5j 4qeheld7q/d,vjip when the plane of the loop and the magnetic field vector are perpendicular.

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57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic field of 0.if:2ui :zuw l 5z:k-u8jbf*mq20 T. Find the magnetic flux thm qw8f* zk b:j-uf:i5luu z2i:rough 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 of an adjustable singfa ,)5,6 le;mfi ylklvle 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 fk5g:d fw ;e as2+:yfwtpz 8va+x8vre3rom $4.0 \times 10^{-5} \; Wb$ 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 .bl;mjecvvefk *0 )s8 turns of wire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane ofc0 sk;vflj8* ve). bme the coil. 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 wirea2+ 6d0 ou.sh cu,tv6op-rwivu8 rs)y with 15 turns 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 alf,:-yidll1te5 +7+qlbl dsn nd 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 n;-*: edydj tymf6,hl /)gu1b unfj7bdownward component of the Earth's mu gbbtjh)n / *;n:eu-mfdj71 6dfl,yyagnetic 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 u :j* 9k,q(jsdiily5 oat a constant angular velocity of 2.0 rad/s about a vertical axo (* yj qkl9i5dus:i,jis 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-sec3*,1f +qslblxym 2ko ttional area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns of wire of h;- jr) lyvci0 l7ez0carea $0.090 \; m^{2}$ 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 8v ,eoy6jnia b -;i zjw37di0ud0wk*d50 rectangular loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis paralle-d 00 ii*6uejkz35yja;bwivd w ,od7nl 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 of 100 turns of wire of areaixgrn6bdi .r.z5 91scx dqs( 0 $0.090 \; m^{2}$ 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 constru1n;it2mriylh d 1 7; bmm-s0kuct a simple AC generator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of the rotating coil is;r nmdhil 7; ysu1im2b 1mt0-k $100 \; cm^{2}$, 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 m; jpw;btmyz+ybk /:u4aximum $emf$ 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. The motor operates on b7 898q arpjhaow, (bo$120 \; V$ 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 resistal ;b*4rt(he(h8efuyu fgp kbdp36c1 9nce of 6.00 W. The motor operates on 120 V AC, and when running at full spee ;1e *8kfuyf 9rgbhdp6(hulc etbp34(d 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 resistance 6.0 W is connected to a 24-V power supply. Tcz,jj2h i) uem/ :lw5oi0 fi*dhe operatingjh c)wzi,2fdu /lj0 m5 o:ei*i current is 1.0 A. What is the start-up current?

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74#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resista+zuzv0o krdsiw-8w 1)u78p st(9 xghonce 6.0 W is connected to a 24-V power supply. The operating current is 1.0 o8rs ) p9tu1wgu0w+z78 od-h vskx(izA 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 Wtgk/4 d(*wf rh is connected to a 24-V power supply. The operating curr rfd/gh kwt*(4ent 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 vs 68 oc d+n153cdpg)tpx+rf vwoltage 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 14 A to flow in the se /80l p( m(*:qknhvc5fpe vvmecondary. How many turns 0fp*8n :v5q(/vvkmmeel( hcpare 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 e4:ffk)ax cuh 0:6oxg gb8u.bmany turns are necessary in a 110-V primary if the 24-V secondary has 100 turns 4xg: ek b .oc8fx6u0)ufhbga:?

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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-th5q y,9o,oxl /cxx/tw y(g wo)urn secondary coil. If the cyyqw)o (x oxxl ch ,,got5w9//urrent in 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% c okfszjv2,7:h) xi n3efficiency, how many amps at 24 V can flow in t7kjcn) 2:h,fzsx3 iov he secondary?

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81#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The secondary coil of a neon sign transformer provides 7500 V at 10.0 mA. Thew) 6mcfze16q4j gfc *v primary coil opermcj6fevzcgqf)46 * 1wates 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 coil and 300 tun eagj *y3iez5:,y4 q3tphhl +rns on its secondary coil+g p*ne ze 4htiq,a:5y3jhl3 y. If 120 V at 2.0 A is applied to the primary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer zd 2t(zj;+ ums68cq qlhas 60 turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, whatz mlcd2q(8+ tqus6jz ; 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 transformer29nttx8 ;frqjda80bt z1 2x gi has 100 turns and its secondary has 200 turns. If the input current at the primary is 100 A, we can expect the output current at the second8rj12q;x bt2i nfda0 tz89tgx ary to be

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has 200 turns. 4 cuvfqt*g,eq);zqo 4 If the input voltage to the primary is 100 V, quf z;)go v ce*4t4q,qwe can expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its sece7daf4 m0o7ol 8va6jzondary has 200 turns. If the4alj v0e7mzoad7 f86 o power input 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 A of current at 120 V. The voltage is usua,- rydzex-ccx ;kl4p+lly 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 p ;rcc4+-xypdke- xl z,rimary 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 1uvmhkd1 + ;i-gwp1 c9knnn a(s/pq,b*20 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 percentage power lost in the tranw1 nkqcv1/n, * g+p;smpa knh-b9(u idsmission 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 usl2a05h h*u8umvwup 2 wually 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 transw0mupuha2l hwv2 *u58mission 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 resiste s f93pmbo/(nance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss fns3op9(m/be 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 resistance oew/ a; ,xtpqjn;0r1 tqd5xp3z y7oxo9f 0.60 W. A generator produces 100 V at 70 A.;;71 e3q n9opq,xatxw jzy5xop0drt/ In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost when the 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 much2.g n +nzo3dqs (jqmq9ld 7:eq less power would be lost if the power were transmitted at 3000 V j q+qlz:9s7q2(no.dg d 3q nmeinstead 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 isdcei78fx. 3 p rt-y/c,aaxpw. to be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with .px/yf wat-pde r.x7ia 8c 3c,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 5.08d g )wd.ket8z A. How much energy is stored in the coil's magnd.8 tkd8)z gewetic 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 a rymwrh);-,o4 /b8krpe .uhymnd an 18-H inductor. What is this cir;8y,e hwhu)r4p-/yb.rmkmr o cuit's time constant?

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96#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the peak voltage in an AC circuit where the rmj 53)r0jxi8hbm3c ke/c-qi .hou2fx qs voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What e1e-hv/yog8*qpws3 bis 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 otg 8qsap( dpn:uv g333y+6 zrxutlet. What is the resistance of the lamp:6d 3rxu p3(8aq3t yzvgnsp+g?

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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 12t-wso z2 +9jisso )0jb0-V ac power supply. What is the peak current through the resisto+ ow) 9o0bs-jsti 2sjzr?

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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 powev+n,60*hj4ocw1y b4ik1ev fizh e+i kr supply. What is the power dissipated b 01y,1c 4 4 ovz iwh+knekijve*i6h+fin 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 resisto1 9a.hr:. 5azxzb bmjg5zp9xt r 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-Ws mhvhl p9 ma;c t5g,mj51st/:u n;ggop- rs*5 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-W resistor (r;ren)4/wfu 5otq l qav4 x4yis $I = 0.80 \sin (240 t)$. 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 indu*e,c 5zzhgz 7fctor at 60 Hz?

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105#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the inductive reactance of a 2.50-mH coil at 1.u,y7trzin h ,000 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 sgj)6uo) rpj 4inductive 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 157i( 5; 8c:fa2f;ysrq m4cpf qak W of inductive reactance 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 of3pu:v ,yazxcpc1 x:0h 20 kHz is appli1x a:px :uy03chpz cv,ed 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-mHmmuqj1cb 2/*t coil due to a 110-V, 60.0 Hz source?

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110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitive reactance of a 4.7-mF capacitor at 10 kH,wm m(nrc1;rlz?

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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 capjxcy5 req;-j9 xpgp ;6acitive reactance at 10 kHz?

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112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacitor have a reactance of 1200) cghb3q bh45c W?

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113#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will the capacitive reactance of a 0.yw;1 puwoi5f.l9t f 9d010-mF capacitor be 100 W?; 5wl.fdywi91f9up to

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114#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 0.0010-mF capacitor at 1000 Hz and 5.0*mbfb) oqff45 V?

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115#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the impedance of an ac series circuit with 12.0 W resistance, 15.0 W in r3 zu-rgtu6zo9 )y,hjductive reactance, and 10.0 W capacitive reacthu3urz ,g -9t)yoz6r jance?

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116#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the total impedance at 1500 Hz if a 100-W resistor, 20-mH coiiw l h4mje62tg)sr: sv2df/7toau + f/l, and 1.0-mF capacitor are connfm: lwj2//guda6t v+7h)r ie4 softs2ected 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 Hzzhle*hj f5,0 a if a 100-W resistor, 20-mH coil, and 1.0-mF capacitf0*j z5e hh,alor 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 inductor, 1:ffesv)t(4,t) y )nn yt-)rc ixu )gzhv*g gmwhat is the impedance atugv:s ch4g-rm f yf* eznn)y) ,t) xv()g)tt1i 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 20jb8psi bov2.)5n 5qqo-mH inductor, what is the phase angle at 1000 H5 onvbq5qspbj. )io82z?

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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 hulizj5hc* .8in a series circuit with a 20-mH coil and 1.0-mF capacitor for a total ij.l5u 8hc *hzimpedance 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 capac;lk2tgu+ ;ktamj6i yz wf4ok2.*hdi l66 m-lpitances is needed in series with a 100-W resistor and 15-mH coil to get a to htu6 mtjyg4+z;.d62k *m wk klol2ila i-6pf;tal 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 sefhiv1wi h+ ( 5i56vuqeries with a 450-mH inductor at 5000 Hz for a total impedan ieih56uwvfi15( hvq+ ce 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/c vnp a59tfy8g+lz/4y k r(sj-kW resistor at 1.0-MHz for a total impedance ofz(+nl/s8 pa/y gfr kvc4tyj59 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-wm8+frzq ,d+aw55fyul f4z o4 mF capacitor. What is the impedance at lffof 4r,w yqwdau+58z4 mz5+1000 Hz?

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125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series wi(bc )itxq l1 7 h03l/bghdd+dhth a 10-mF capacitor at 1.0 kHz for a total gq7l 1ld0 hh txbb)3dh/+di(c 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 with a 10-mF capacitor atuo5+v .prcnv8g9 ;n dvwzg:z1 1.0 kHz for a phase a5 ovr.9+ zzvd gvg:;wuncn p18ngle 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 ser9fi hg+o.b rc8ies with a 30-W resistor at 1.0 kHz for a total impedance of .hifgrc98o +b45 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 120 Hz. What is dl7c.,;j p5k6cor sos the phase anglpkr 75;, jo.lc6sdsoce?

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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 150( j6aq hiot 30os4-fa lg- o6kv+fvr+y0 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are conn+ofril3ot y-o -vhf6kj+gv s(6aa04qected 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 ca6pnlz6ve.b u/ pacitor, and a 0.350-H inductor. The cpbz6nu6 l/ v.eircuit is connected to a 120-V, 60-Hz power supply. What is the rms current in the circuit?

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131#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistance of 55 W, a capacitor of capacitive reactance 30 W, and an induct.e9svuy fwxei2),m. 6anv pz;or of inductive reactance 30 W are connected in series to a 110- z2fei9.w v)y;seu av.xm6n ,pV, 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 circuitia( b7kf)w -qir,lu4 j containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H j7rbakw(,u l-fi)i4 qinductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a 500-W reva.x(0 l jjhva8 j1wp/sistor for a phase angle of hj/8.pa wvl xjav j(01$40^{\circ}$ 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.u0 0* z2pkysao At what frequency should the circuit be driven in order to have maximum power transferred from the drivk0a zs*2poy0u ing 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 w(,)*u 2jlkeg 6awquvkith 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capac()6q,v a ulg*euj2 kwkitive reactance, when the circuit is connected to a 120-V power supply?

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136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an AC circuit (3kd6 ztm,qxb(px vg5is $63^{\circ}$. 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. What iszwkkvt2 0a bm6n 8c7e. the power cv0 tz7 e k8kban.m6w2factor?

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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 resistor, a x/1k kasb.4s z10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power 1ak4bz/sxs.k 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 ap he rm5g90 go5 i15hoxz2td-h1nu.pn 1.0-mF capacitor and a 15-mH coil in series?1gptrn5 phd5mo2 1uh.zeh 9ox0 g5n -i

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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 gw6: sgbjy2qau) /ty:l * sq/vmc8an ;capacitor for a resonant frequency of 12a sgsb/g8ymylaq;:/ t* ) w6v nuqcj:0 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 inductor for a resovy;-p0m5 p:h. t pv g3cegi9qonant frequency of 1000 Hzt qvh9im0pc eg g-53.pp vo;:y?

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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 a6** 6gp 6a ialtjknje/ 30-W resistor and a 40-mH coil if the resonant frequency of the circuit is to be 1000 Hz? 6e6 jgtil a**/jkn6ap

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