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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 magnet, no -pfthnlu+j((cv* ic 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 indux ub43-iq ip7nction 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 p.zateh5 dy4 ,yroduces what kind of change on the ,. 4tzay5y ehdinduced $emf$, 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 hfpp e8,9i7uf 7;sb l/z/ zi.w yc6qtaof the magnetic field through a loop of wire produces what kind of change on the indu9 p7ehi z/wp/csf7u, b zay8t;iq f.l6ced $emf$, 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 onp, wf(u9qt x0z-,l 2vyc3oqchange on the inducedol-vc ,3y,u 2foz xtqqwp0( n9 $emf$, 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 magne .gbl y u3v-fybxp40c( ewk4k7tic 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 loq h6lvq/a 9x6aw, the direction of an induced current in a conductor will be that which tends to produce which of the follo96 hl/oqqxv6a wing 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 u/k zd9mqday-ad/b 8+ horizontal table. A bar magnet is held above its center with its north pole pointing down. The stationary magnet induces (when viewed from a+dmuk/yd 98bqz /ad- 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 fc n:( aw h3xle)-ea3qqlat on a horizontal table. A bar magnet is held above its center with its north polea 3n(q)we3:cxlq- aeh pointing down, and released. As it approaches the coil, the falling magnet induces (when viewed from above)

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10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a table top in a region where the magnet g0 opl30tqm.iic field vector points 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 i l3q.0gpto0m fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top in a region where the magnetic field vect2i;6 0dbatsgl or points straight up. The magnetic field suddenly grows stronger. When viewed from abov0at6i dl2;g bse, 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 s -ix70oo0kk+ aygvq )s,y2zy in a region where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, what is the direction of the induced current in thi0 oxkoys+gys)vy0 i,2z-7k qas 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 0ig3x,i (x7zz 5)yr5upi bcmltable 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 above, the induced iry ) 5b(mpu,gxxlci0zi 537zcurrent 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 throug6cix hoi rq0z 7bk xay:.-)/fzh a loop of wire with the north pole entering first. As the north y6 rx:qfk0zzx.i)ac7b-/ohi 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 constant angular speed about an af ,wo i6141hvndn+os6;obqeaxis whose direction can be varied. In a region where a uniform magnetic field points straigh;fdeba66 s ooin1nv,hwoq 4+1t down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be zero?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at constant angular spee2) jky+talusqs 3v/,hd 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 axis o,)3t2l+ssay u/ hjqv kf 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.rn(qh.w1xl. n0 zr(em
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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 t-;tp-5d c; llak d:t;fpzf)p oz0-vrahat an $emf$ can be induced in a loop of wire.
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20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A wire moves across a magnetic field. Thkzp*s /xfwyr 4w/r; ,ue $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved northwaw- ls4,rctd7tf n pu2.rd at constant velocity through a magnetic field that points straight down. Make a statement concerning the potential induced across the ro ,7trs ctuwlfn2d.-4p d.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bari ,9fhem w7i2ookg//r 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 transforz erwd*7mc7. na(1yhfms

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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 revolutionsh qc2t bj*9mq-u5rt2d each second. The frequency of th- qcd2tut*9m25brj q he $emf$ 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 us-hf ,-2t bgzym) 0gwudiy9 6qped 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 des/ 4zz5z0gef ovice 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 secondavinvt p9)x-ri1n r+oqr - qo82ry coil contains more loops than the primary coil )qi-8i+xqr pnv torn2o9 -v1rthen 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 containsrfju-z xpg+q:1,e 3fd more loops than the secondary coil then it is a3ezqr j:1 u+-fpgfdx,

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29#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, they:bvav) 3iajt: ra b /bi/d.:p 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 circuiife-imwy1 ,9rdnzefr0b .,h2t,

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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 con;q(a ,t- qo2zvh ;elltg5+rylnected in series to an ideal battery of constant terminal voltage. At the moment con ,5qlgyvlh2er-t;at +ol(;qz tact is made with the battery, the voltage across the resistor is

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series tb q. adkbh4zl55)f 1mio an ideal battery of constant terminal voltage. At the moment contact is made with the battebz4q5di m5b)f1l k. ahry, 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 witpc-c-+*zrr 2ivi kg6uh inductance L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the 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 resista:ienjg0g5 t v3nce R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a batter3+4qxjy 0oz*9ri3iot zi; acpy. The time constant for the circuit represents the time required for the curii ;z3zj9+o4*pyit xc03aqor rent 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 in .ckxq;mmq); mseries to a battery. The battery is suddenly removed fr xc)q.;mmk qm;om 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 have the jf6360h bbloc;)-om,av cdlusame 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 s t3s6uhs9lbhi hvqfjg)( /71eupply. On this circuit, the current

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39#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure inductor is connected to an AC power supply. In this circ s)l3adbmr(.y uit, the currentl 3.rabyd(ms)

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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 f)dz dh.y-,lz frequency i y.zl-hdfz,d)s tripled?

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41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the frequency of the AC voltage across an inductor is doubled, the ind/bkar0je yhnr)o3+6 yuctive reactance o 3)aejhr/ y 0kn6r+ybof that inductor

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42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across an inductor approaches zero, thcme9y xcw +(b6e inductive reactance of that c(bmx 9 y+ewc6coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In this circ-smz 2*l(au3xtch.m1n psu , auit, the currentat-1, ( 2.hnuuz*amm 3sslxp c

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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 (ifwnbz: k:9 mthe frequency is tripledn (zf9:bm: ikw?

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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 acr7/6z eg6kf(0g8w bfuvsq m;okoss a capacitor approaches zero, the capacitive reactance of that zm/ ;uke6k8 6owq gv(07gffbs 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 voltagesrwz8s7 ke:8mhzw or5y7 9r9dp of the inductor and capacitor in a RLC series circuit?5r7 r8z 79ohd me 8r9ypwk:swz

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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 mh;mu4 93kcpg RLC 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 cirj7qlz68wawfhg)t)(e 3o w l7 lcuit increases if R increases. When is this stateea7wlo)87 )ztgw3 q6lw (lhfjment 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 increas+t)* w4my t8pnyg xf:aes 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 if l 4d*c5 sgy-0yceu)ut $X_C$ 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 capacita0r3 9 20zpcaycvbz4 sbnce both double in an LRC series circuit, the resonant frequency of tz ysvz9c2b40p b30rac hat circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is driven by an AC applied voltage.5q-p3dflt( 4n eup3dl 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 occursgdy,vdhsj ikx e)9 67*d t)px8 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/2k hzn3h -g mmo3om g)nbq6c1 rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop whkm12o6nb3hm nc)g o gzmq-h3/en the plane of the loop and the magnetic field vector are parallel.

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic fqf9dnl:7vki f0n:4fz ield of 0.20 :i9f 4kfd n q0vf7:lznT. Find the magnetic flux through the loop 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 radwo1 ifg-ez0 v:uopk7.ius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop g:vw e.u7z fpioko01- 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 adjustafqhb*ay+**z 344fw gu,x vd gable 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 jep-qm up+ b p.w9,+zs$4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a square frame with sides iij b nidd)rmm.r f9.lh*6c))18 cm. A uniform magnetic fi) . 9r)jmhb)6micr* d.ldiifneld is applied perpendicular to the plane of 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 wire with 15 turns and-dfv8wr /01fp favv k7*f6x gv 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 a)kxuk l(z;n u1nd 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 horizontally1k1kkcxy8h mes 9 y;y2 at a location where the downward component of the Earth's magne me 19x;kkyyyck8h1s 2tic field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar that is 2.0 m long rotates at a co/ )t 4q,htgnmanstant angular velocity of 2.0 rad/s a qn, /mthg)ta4bout a vertical 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 loo qy/7)gck* 0ytybcpnv dkz08: ps and 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 of 100 turnou9ix;) doo;f s of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 rectangular loops on its armature. Each loop is 12 cm dz,8x-o/cw utg 1f8z mlong and 8 cm wide. The armature rotates at 1200 rpm about an axis paralle fxwzm-1zutd cg8/8,ol 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 consis x(y /ct21rre/gunn1k ts 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 current.

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that you wish to construct a simple AC generator wbkyfc1n y-7-h xxi-rzi- 3i8g ith an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.07 -xckx3zfyriig -h81--iny b 50 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 am )qpyzd-: p*r 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 6.00su4 8;u2 hd2sjadar vw gv./)q W. The motor operates on $120 \; V$ AC, and when running at full speed it generates a back $emf$ of 105 V. What is the starting current of the motor?

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72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor 0cppt5tc8jd d ru92 **oobprmgp6 ;;s have a resistance of 6.00 W. The motor operates on 120 V AC, and when running at full speed it generates a ba6*8d 0ctp9bgppr pcom 5o dr2*tu;js; ck $emf$ 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 i,zc8ru w -enoee6,0e vs connected to a 24-V power supply. The operating current is 1.0 A. What is the start-up curre8v r-,ecwn0e,zeuo6 e nt?

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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 5tva(e/7 pydb resistance 6.0 W is connected to a 24-V power supply. The operating bt y/eap57 dv(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-V powejk0fpkd r0-.k (whn:.pmvao2d kou 8,r supply. The operating current is 1.0 A at fuj ,ddu(k k..omrh0ap k2 o-pn8 v:0kfwll 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 nub7-u gb/;yqdl/5b 9p/e tbiteeded to reduce a primary 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 14 A to flow in the secot4)(* yt )ad5orrwsl bndary. How many turn d b(or)as5r4yt*tlw) s 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 ys) .0hqj4 o ei(ji2l uo,ky*q24-V second q(jusqi4hyio2jy ),oek*0 .lary has 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 2000-nd cg.jysr 5l8yb/7;vturn secondary coil. If the current in the secondary is 3.0 A, d v/ ;ngy.j8 5c7blrsywhat 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% efficienja 1nap(,hzl 3 z:i;avcy, how man;laaj ia( v:p h3zz,1ny 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 transformer pneq6yi6l +d8jm; oq7lrovides 7500 V at 10.0 mA. The primary coil operates on 120 V. What does t+q d 8nlj6le 6qmy7i;ohe 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 and6,9soo--3 :oryajvhyo 1yyu w 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltw9r yoyayo1u,h: - 6yjo-v o3sage 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 andl p*iez67r1 101oiv n,iqndw zfel82d 300 turns on its second8i1n,12il z dlp*n 1idq6r ew0eov7zfary 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 turns and its secondare +l oxj91*avnf6igd-y has 200 turns. If the input current at the primary is 100vxe1+ -nidl9*f aojg6 A, we can expect the output current at the secondary to be

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turdajbrxfqi0mstak7 ) 0( t.c63ns and its secondary has 200 turns. If the input voltage to the primary is 10xq ajk0r 0 ic(3tmf6tasb7d ).0 V, we can expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns andyx.( h 2o)jmzmikw+*j its secondary has 200 turns. If the m m2*(x+ik yjjz.o) whpower 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 usually stepped8tq ve*w(zlc6ea i83c up to 4500 V by a transformer and transmitted throu* qceti8wczav6(3e 8l gh a power line of total resistance 1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 12 ypt9-r uc4ncwt u2f )7j)ho;t0 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistanchu4ftp2ct)7co jw9 ) u- rynt;e 1.0 W. Find the percentage power lost in the transmission line.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. hbly x 1qo;i;z;ny l;gr8)hn8 The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistan l;88b x1olhq iyy;hn)n;grz ;ce 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 W.x0skupp :d6t. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy would be lost if the trap pt:0 x.sku6dnsformer 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 bv,f:mofu;u d0 ;76wj/vxmos line 50 km long has a total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is fmw7j ; ovv6fd:ox,m 0/ ub;usstepped 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 Vkledsch*61 tvg i h,t4 u(0pr4. How much less power would be lost if the power were transmitted at 304*61rgt t0s(lcphh uke,v4di00 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 4jwrso6 f 9l7izn3y v9, wyvj;440 V at 20 A. It is to be transmitted on a line with resistance of 0.60 9zfy9sww,iy;6j r7v4o j nl3v 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 enery,st t ,k6xi9zgy is stored in the coil's mi,t,tzskx 69yagnetic 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 reym, js3vo:h7fogx* yi.qwf7; sistor and an 18-H inductor. What is this circuit's time constant?s of 3ih.*jy mfqv;y x:7wog7,

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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 volzzmg le 0of6;83o gfxvq,5ug 7tage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is place c,iyrdiq..j0d into a 120-V AC outlet. What is the peak current?

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98#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outlet. What is the resistance of the lagr54 crtpb)o2m )2g4 rrtop5bcp?

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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 fca *d r:ztb7j /;p;,dhuf ll(a 120-V ac power supply. What is the peak current thl7drh: c(;z a,pfd *t/f;j blurough 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 le 1+940ydm9 yrpcj fz120-V ac power supply. What is the power dissipated in j z9my40py+fel dr19cthe 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 re1rbk 1sr/iwz0sistor 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+secd e *a:vk2 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 resiszhxt *uwe;w+/ tor 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 60 Hzt a2-::ru wo1ayi. vnc?

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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 10 ek.abotg+jlxb4s 0q2h ./+nqsus3 k;00 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-mHloem.h8/t1wbl l rg/ ;8mtnf- st4tq 6 coil have 14.0 W of inductive reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessaryjgjqpu64*j,b0 suc tg+f emp6 1au:vy*y,8vp for 157 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 al b k:)m;e.j2/f olw* 0iufluct a frequency of 20 kHz is appllflk:biue . *w;om0 culj/f2) ied to it?

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109#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 2.50-mH coil due to a 110-V, 60.0 Hz st gm1- .wx0hh*arjf(j ource?

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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 reat 9izdzmd5s7 /3np 8slcyc ;6actance 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 50k mj qgb 0t+tdj,3x+k, W of capacitive reactance at 10 kHz?

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112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacin 8c/b kd*hej5tor 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 of a 0.010-mF capacitor r)j ff5rwcvts5/c293 h/rar abe 100 W?t3crrr rhsa/jf) 2cf5 /vw59a

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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 1rn fm2x7e: q d96dog5af ecze.,mi7 d5000 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 s5a yue-gch,2utuei 8 *eries circuit with 12.0 W resistance, 15.0 W inducu h-ciueya58tg2*eu, tive reactance, 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 impedane pqy+:sdb* 0dqoj:m8):ty f tce at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in se yb tm0e*:odd+pjq )y 8sqf::tries?

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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-bhw a3r5w2yh+;z ctb 3x 1pks, 20-mH coil, and 1.0-mF capac -;5zhbsx32+ka3yb ct w1pwhritor 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 s*do u+vz3+,gnev wwd; eries with a 20-mH inductor, what is the impedance d*dzv+ogw+ en3,;v uwat 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, whatq kpoi ,(dc kd/ w6qd(j*u6x vm4.qn.obtx .+x is the phase angle atm o.kqjdcx4*+ qx( q.owu,vb(knx6p. d/di6t 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 anht2r/g/c opk:s :r*j: jfdcyc n-x.k/d 1.0-mF capacitor for a total impedance o:sxrh -kcor *gdccpjjn: 2k/ :/t.y/ff 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 followip6c,yrjslb d39 mw8a 6ng capacitances is needed in series with a 100-W resistor and 15-mH coil to get a total impedance of 110 W ayj b,pr6mwd8 3al s96ct 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( bv ayz mvz971e,9osv be put in series with a 450-mH inductor at 5000 Hz for a total impeda1svb,e ovzz9m a9v7 (ynce of 40000 W?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in series with a 100-kW resistorvl6x5l:we x u9 8)aoaf at 1.0-MHz for a total impedanc5v6ola 8af xex)l:9wu e 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 capacitfll*wk ;co,: xor. What is the impedancexl:cfw*,l ok ; at 1000 Hz?

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125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in seri9/+jr x anyg:oh1qqt(j6; lxg es with a 10-mF capacitor at 1.0 kHz for a total +9/qahjj 6yg gqtl; (xx 1:ronimpedance 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 needev(kp0g (tkx:fd in series with a 10-mF capacitor at 1.0 kHz for a phase angle tx((fvgk k:0p of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W1iktn q9g7p3 z6/fmya resistor at 1.0 kHz for a total impedance of 45 1q6/a9gk zfm pit7y3nW?

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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 100d yq3xf+(q5d yv2 m1ok-c.vy7sdblr.1qso o8 -mF capacitor at 120 Hz. What is the phas1cqvs3q8kd.yo br2.y-xdyfq1 s vdmoo+ l(5 7e angle?

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129#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows at 5.0 V and 1500 Hz if a 100-W resistor,k2 .h ua: 40mutwj e3qh4t*qtw 20-mH coil, and 1.0-mF capacitor are cuuh t43aqm*hw0ktq4 :j2 e.w tonnected 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 a1ba+:z qihoto 4)yb4)0ymlmb 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz power supply. What is the rms cumybt1)mh+)y4aob bi zql4 :o0rrent 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 rea5-d)k kf*s3vhij isw 5ctance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz power source. What current flows in this w5 v5-* kf)sdskjihi3circuit?

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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 contaas qp5*3ewv 8wining a 50-W resistor, a 10-mF capaci 5* 8wwqsavep3tor, and a 0.45-H inductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series with a ,yf ,elq u53t9dthu)o500-W resistor for a phase angle of udtty9eq , u53fl,oh)$40^{\circ}$ 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 0ojta,. f,z/ykx-z l-yjkd0amF. At what frequency should the circuit be driven in oykfx,-az.0d-z j ao k0/,lt jyrder to have maximum power transferred from the 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 /:g e 1wb: xjn gh,(hk85tqqj8)lkpbzwith 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connectlghptzn8)j(,:xqbb ew g /:8jkq5h1 ked 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 circak5un7oiw )kz7 5e*f iuit is $63^{\circ}$. What is the power factor?

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137#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ac series circuit has an impedance of 60 W and a resistance of 30 W. What is m3 g;boasdk*o kc65:d the power ab*3 d6o cd:5s k;omgkfactor?

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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 contavpkpo7ljj+q,a5/:g xining a 50-W resistor, a 10-mF capacitor, and a 0.45-H ind/7+gqapk,xl vjjo5: puctor, 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 coilu7l hxog-lr )4*tj y5y-x,e ql in series?xglxr)l5 q7* yjt uly,-eh-4 o

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is needeid4uft*m 5 i4wd in series with a 4.7-mF capacitor for a resonant frequimdw f5u*t4 4iency of 10 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 in7 z3mzk))zb.+ o y j aife)p6lxsz(g6bductor for a resonant frequenc.iz )+ b gb3zym)x6 a()zs7foez p6kljy 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 m3:alq 6 qhve8iust be placed in series with a 30-W resistor and a 40-mH coil if the resonant frequency ovla:3 q8 e6iqhf the circuit is to be 1000 Hz?

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