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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 uqg5164ajdf zch) ..v.l vxexnnits 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 induction state8njs73nqd+/4 qvljmmdy x: 2f s 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 produn-eg c8j(5moq ces what kind of change on the induce8q(5g -j moencd $emf$, 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 wir49;q6k3z*qk2 m iz0bxtaz iyee produces what kinm 3izk yit96b40eza*zqkq;x2 d of change on the induced $emf$, assuming all other factors remain constant?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the diameter of a loop of wire produces what e vkv7 i:;hp do;lakea(4i2-itkv j63kind of change on the inducedhi7(e:k otv264j;iik3p -; aaldkvve $emf$, 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 fielwedm4wf 1n,/me:1ee 5q z0vg8o i6l d7- nqbjod 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 cur4 ffbfws-5w26h7s u5 1tw *exjtkdoq *rent in a conductor will be t 5o1ks5uthsfw 64j2w*f wbf7*q-exd that which tends to produce which of the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizonhz yf/ 8jaw44w1q 94sn 4vcgumtal table. A bar magnet is held above its center with its north pole pointing down. The stationc 4u144g ay w8whj4n9msq/zfvary 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 liesmjsk22 / qwlw) flat on a horizontal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magnet induces (2w/w2m kqj)l swhen 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 wher+us7 axr hhc)hws.5p3m:44mpy p3bsne the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the ih34 .5nb hssxmy+muh awppp74r ) s:3cnduced 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 regsf9rrz+bf1o*b .zc0ssv i:2 cion where the magnetic field vector points st:csv z01rs9 *bzb+csr2iof f .raight up. The magnetic field 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 ju i9-tf7vklwn* i;ln3t;y+pregion 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 this coil as the field disappears?u ;l;fi+nt p3*79tykwv jin- l

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A long straight wirekpol8zt ;uo4/, fu, dx lies on a horizontal table and carries an ever-increasing current northwardof d,x,kluop 48; /uzt. Two coils 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 wire9ned zef*3ai ) with the north pole entering first. As the north pole enters dea93nf)i*ze 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 angulpb*g t62ptcs8ar 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 ostt6p*2cgb p8 f 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 spe9qd.lzb iu n b+z:/50+ol-k dmpcho/sed about an axis whose direction can be varied. In a region whez+d o+ /npul 0l9ihzbb:/mqcko5-d .s re 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 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.pj,7 zo+iz c2h
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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 a,yp:zwmj-2zydx. bx* n $emf$ 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. wi6nad;x;nl g kv-0;e 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) is moved norg,o+(shmy4 *y lo2 0wlpgn5n ethward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potne*0m2l54w +g yo pnolg(,shyential induced across the rod.

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22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar rotates at a constanu +ro)l 1n,6 (*lgjmfq lfi255zzetjbt 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 tray7n -p2p *46bhgj bakt;h ey,snsforms

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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 second. The frequenxpdx k/4ld5;xtogo7 8l0dc/e0m2tt scy of thd2s/tctx0dk 5 4/xoedgox78l pt; 0m le $emf$ 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 usm*7s,ex7 (pmg1wb um:hcov8yed 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 deviceze:yu yu xz)73 g()seaa3af 8d 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 b 2- 7y,dwiayt/fq;xbcontains more loops than the primary coil then it iyf/ 2dibtw;,q y7-bxa s 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 4pf08x*szewi; jpj6a the primary coil contains more loops than the secondary coil then ita 4*i ;j0j fxzesw86pp is 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 4r3* pm6ba2j)r lg8av a.jlipinput

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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 7qo, vv-.;fuucg/kzg 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 series to an 09-zc amjcng- ideal battery of constac9nczg- j0 m-ant terminal voltage. At the moment contact is made with the battery, the voltage across the resistor is

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32#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductoh :0 kmfymxfbl :mmqzu,w -mf/y-+o52 r are connected in series to an ideal battery of constant terminal voltage. At the -fqub:ywy-kml5/f +mmm z 2mh:o fx 0,moment contact 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 mh;cvw/) 1aty:(aifyinductance 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 wtbha*e-)x *th a18lw 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 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 tf1f /t as +d osil7erl82.jnh8o a battery. The time constant for the circuit represents the time required for the current t+t8o 2.f far8 s/l1elndjhis 7o 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 series to a battery. The batte0mjmitq s( k)dhox* 7gtb3+n9ry is suddenly removed from the circuit. The time constant for of the circuit representmxs+n7dmqo9bkhij3 )* (t0 tgs 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 exc,av c)n hd/3ncept:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connected to an AC power supply. On this circ (doy);xzv;l yuit, 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 pw/h- k2( gwdqbvf1hy 0ower supply. In this circuit, the currenthykw-/0gvb( 12df h wq

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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 circu,uzts+gc-6-w 5ditp lit changes by what factor when the frequency is tcp- d-w i,zu sgtl+65tripled?

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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, ttf/w- q8,tdzhutq91 , 7ybaux he inductive reudxbfw/1 y9, ut q ,ah78-ttzqactance of 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 induc m).9u+p3euf s(0mznxjef +oloww*7.n ok l9xtor approaches zero, the inductive reactancu )exp3n.0wj+zn k (s*.o9l xm9e+ufomw7flo e 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 conn1rxofz7tce6 dcx t4c1+z54ul+cz j6x ected to an AC power supply. In this circuit, the currec4 +zt6 fzucx16rtldjx e7xo5c c+z41 nt

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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 theg*a rf-hd-8*cip (iww frequency is tip* r-f*8da(-hwgwciripled?

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45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of the AC voltage across a capacitor approaches zero, 0uxzy+8)x6 (jjzw fld the capacitive reactance of that capacito yx0 j8(j+ldzfu6z)x wr

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46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle between the voltages of t* 1cxad,gsyr0he inductor and capacitor in a RLC series0ay,c 1grdx* s 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 circun(z9pxmlw 9-nit 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. v+eft p, f*k,n;puxx 6The impedance of the circuit increases if R increases. When is this statement true?ppt+f,x*efv;, kxnu6

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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 increases a)rqdd6 1su n.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 circxuw 6(qvp v3n4uit 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 series circuit, /yg0(tk+vria5oppz / the resonant freqp5ak+0//zr i ovypt(guency 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 isa* 6kgoe3t 27rgpjtw : 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 pnn1k v:/wux;t+ o, pog4aa,tRLC 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 il6 2kdz 02tj+06xi-awgspr yvs rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop whenlri20gw zt6xa2j+k6 d pys- 0v 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 t bd t/w, ,;j00xechxpin a uniform magnetic field of 0.20 T. Find,hp; 0b/x ,wj t0xtecd 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 radius 0.10 m is rotating in a unif3v8 fjxsrq/+ hoq) bht.y7mr6orm magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and theqb qyh8o6)j.7sr+rft/ mx3v h 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 single loop is re nx uya+b3:a vrwei080duced 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 changeszk(+j xmfyij57-1 ttb(um fg; from $4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a squad:s ztt7gp4v*re frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes unifos dttg:*z4vp7 rmly 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 ,r4,edj* fbtpwith 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 and a,j khx.qcnyz gn5i-vt1q3d12 rea $0.20 \; m^{2}$ 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 m-m;b)qfx o:uo3(. u- rkq bgq)rz b3jof 60 m flies horizontally at a location where the downward component of --.ofrjb3zqr k )ob;bq:u(xu mq m3 g)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 2.0r sk(s7er. ue* m long rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ener7 r ks*e.us(ds 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 crwq.hqkjw hw(7--g fao1(/czaoss-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 turns of wire of area .aqb4kq8/ pct $0.090 \; m^{2}$ 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 b.nv 6gjkgn c8cne 7-k.vfp+8 rectangular loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about g7v kn nb-n8veg8+6.f cckjp.an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular to the axis of rotation, what will be the maximum output voltage of this generator?

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68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 +zx4..o(k q0gpkbd wqturns 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 bh hzt01:y;,-nsy cyo/a ei8y with an output of 12 V maximum,i y;y caehs1tb h0/8-o:ynzy when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of the rotating coil is $100 \; cm^{2}$, how many turns are needed?

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70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are designing a gena5dix lv2.:,4nc c 6xjll.cymerator with a maximum $emf$ of 8.0 V. If the generator coil has 200 turns and a cross-sectional area of $0.030 \; m^{2}$, what would be the frequency of the generator in a magnetic field of 0.030 T?

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71#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have tg*.ot dtnd: +t uf:n1a resistance of 6.00 W. The motor operates on $120 \; V$ AC, and when running at full speed it generates a back $emf$ of 105 V. What is the starting current of the motor?

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72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have a resistance of 6.00 W. ewy. f4k(lad7 The motor operates on 120 V AC, and when running at full speed it geda47(fkewy . lnerates 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 intern fjr+yy8ln9h 3x j5k6qal resistance 6.0 W is connected to a 24-V power supply. The operating current isjy nj65y3 kf8+ hlq9rx 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 v-wp nodg)7br4 (pf,+qg0fsi 24-V power supply. The operating current is 1.0 A at forbp0ffpgw) +-s(4 7,vg din qull 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 power supply. Thz/a pg,(s x+dve operating current is 1.0 A at full speed. d /+,vz(xgs ap 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 transformernzu4c ddal/i .07 q43 gkbaey( is needed 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-turnv1x 2xi 9kiy/y primary of a transformer causes 14 A to flow in the secondary. How many turns are in the seci 9 xvxkyy12i/ondary?

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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 q)k8k ; x+a3azhh/syv the 24-V secondary has 100 hkz 3sah); q+ayvkx8/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 500j)oaol1b h0+hf :o 4; 6mnbfo.on5vb j-turn primary coil and a 2000-turn secondary coil. If the current in the secondary is 3.0 A, what is the current:1an0hmvhb jn5of;o+j f4 ) bbol.oo6 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% efficiencps9cu-+xnuffe. - 3xziu -sahgds9/ 4y, how many a+9fgu3h -zss4.xa 9pfud/e nu ix cs--mps 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 provides 750+6lgy:;yvu wrj ;;hzt0 V at 10.0 mA. The primary coil operates on 120 V. What jluvy g;zt6r:h ;;y+w 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 t f2;vazag s3:zurns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A zgz2a;a v:sf3is 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 has 60 turns on its primary coil and 300 turns os/p8r kx mvxn lty(097n its secondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in r/mvk78s (p9t0 l xnxythe 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 has5gll,xb )/ah q i wi f-/5-p8nytq:ofx 100 turns and its secondary has 200 turns. If the input current at the primary is 100 A, we can expect the outputw,pgif 5x/ f a-nt5yb-h qx8) li:ol/q 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 turns and its secondarwu zdk+jouh 5.43o-qo y has 200 turns. If the input voltage to the primary is 100 V, we canj +u d3o ouw4qk5z.-oh 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 secondary h9f 3pfxuwk ,yf vt.7q/as 200 turns. If the pvpf3 .uyx,kw7tf9 qf/ ower 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 voltag+k-/44u/uz hvlma pnd3vk.wee is usually stepped up to 4500 V m.e/wz+ u4dvp-nu3k lahk4v/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 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usually stx)a4i3-kx s xqepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentage power lost in the transmission lx )x3s4xqi -akine.

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89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator producesk*hip6rt cb b1xxb 631 60 A of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line ofh6x br16b 1 xi*pbctk3 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 h)tg 8mm dvt zx0c58fc :gr-t:. vb3bdsdp) 0xias 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 stepped up with a transformer with a turns ratio of 100:1. What percentage of the orxcg8t0 rdbgtd5 fd) st)v:v3zb0pi m-.x:m8 ciginal 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 toe+:x trxsne vi2 h;vw (:cn2c)tal 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 stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lostev:rx2n; xns+vh2 ec)(:wc it when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W lin)+qbz;v2xq6jn gf*s n e at 1000 V. How much less power would be lost if the power were transmitted at 3000 Vb6;2g z)sf*nn+xjvqq 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 be transzsbi sa c 3b7+b -3tbowwqm4s8buv7-3 mitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped uwsoqtbs3+ c 7ib33a z4ubv-w b 78-smbp 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 cur1j0m zb3(s9oahxis0,cny 3 dhit9a1brent of 5.0 A. How much energy is stored in the coil's magnc9( h3tosnbxyis3 iahd0z 0 ,1bj9a1metic 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 an2fmp)oxaxb(dqdp.g(/d69/6vgtf cwsp q u4/ d an 18-H inductor. What is this circuidw 6pqdx6 .p(/q(49o/ d)uf/mvgcs pfxbt2agt'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 circuiehsn/ybc+ t6 /t where the rms voltage is 120 V?

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97#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 150-W lamp is placed into a 120-V AC outletf* urat4+ v-iyl3 (cfem9uy2f. 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 tha7pv(z 7kkc.pe resistance of the lamppa.c7kzv k7 p(?

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99#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a om-0 lz;)kt wn120-V ac power supply. What is the peak current through the resist; no- zwm)tl0kor?

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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 connecteda *hg ) 8v)cls8a)ixuh to a 120-V ac power supply. What is the power dissipated in s8 v*ul h)ax))ga ci8hthe 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 -c0 4(mk78 spoem r4-q oteb(p)1pas9hvt qbn50-W resistor 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 5 cp2hl-ut 07(miuatn 4hcko0 20-W resistor is $I = 0.80 \sin (240 t)$. At what frequency does the current vary?

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103#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor is2nr2:hm) yx0fp(7aaqdb au x+ $I = 0.80 \sin (240 t)$. 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 Hzad,edbnm)o 2vu4 4sq v.g- cl gu:0pg8?

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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 re9d9)6nq w*d 8,x,ckc qmfogt0r 0nhpkactance of a 2.50-mH coil at 1000 Hz?

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106#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will a 14.0-mH coil have 14.0 W of inductive pehss,z;9q*u reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 157 W of inmw;5t: c,*eh lz euo1bductive 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 e0x8., bvcapf inductor when 120 V AC at a frequency of 20 kHz is appc 0x8p v,.baeflied 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 cj eppknds;: utr8 v)+trnf940 oil 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 4t,a-nt 4(gd0+ p sbwex.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is needed to have 50 W of capacitive reactance at 10 kxe ng/vggp * h+75xrys) a7,bpHz?

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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 W?ttp9gb,nmhsc+y ubz;z h l- f:w:, *8c

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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 th-z6)e5qno(;c2qpy 0u3sedq jh (qq wr e capacitive reactance of a 0.010-mF capacitor be 100 W? qqc(qeh0 ;2 u(5qd3wj 6sro-) pnyzqe

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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 capa.zuth3a+ -wh9nsj 3ur )651c jsuqrflq j) s9ecitor at 1000 Hz and 5.0 V?

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115#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the impedance of an ac w:-s)gv7w(hn a2s5-pm h3muxe6rju q series circuit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W qrga(3whvss6)xe5 j- 2-uphmn7mu :wcapacitive 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 imtcd al8 0s.cu,pedance at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF ca lct8d,acsu0 .pacitor are connected in series?

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117#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle at 1500 Hz if a 100-o:d bu u)4q3-1c rqsof5gdwm(W resistor, 20-mH coil, and 1.0-mF capacitor add:qmor-ou5q ) ( s1cfug3 bw4re 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 inn 8k2oqg aqqt.c3af63 series with a 20-mH inductor, what is the impedance at 1000 H q3ata2og3c .qn 6k8qfz?

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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 induc,hgux yshxm)6p*k+9 tduyh ub 9j00,gtor, what is the phase angle atbx6g su90 p yh,xu0j,gh)d tkuh9m *+y 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*fz 6vax)5cyxp 6 q zssf4dkg- r ivop)7*kq8. with a 20-mH coil and 1.0-mF capacitor for a total impedance of g ys4k 5ix xkdvff* so)-qv)zz*p.r8cp76a6 q100 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 capacjns*-c.4.7oe 3gzsa vamq3qyitances is needed in series with a 100-W resistor and 15-mH ca cnz7qa o3 qm 4jyv*3-e..ssgoil 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 57qz em *75(bjeqtl /sf000 Hz for a to5qeql*e/(7zfsjbt 7 mtal impedance of 40000 W?

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123#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance must be put in series witfi oo+))vss5 lh a 100-kW resistor at 1.0-MHz for a total impedance l+v))ss oio 5fof 150 kW?

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124#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected in series with a 20-mF capacitor. What is tds6rkux3r* 861rsw ha he impedance *war86 dhsrkrux 3 16sat 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 with6mz7i*ne flpa(6xt f8 a 10-mF capacitor at 1.0 kHz for a total impedan87z l6*fpt m ai(xefn6ce 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 at 1.0 kHz for a*c:2puw df;y; 6kklk g phase angpk2;duky6w ;gckl*:fle of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1. 2nnqcaxg:f7. 0)w tsa nc.i.t0 kHz for a total imp.t2x0agiw)an.7qn.fn c sc :tedance of 45 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a kt35ml , x abh9wk44uw100-mF capacitor at 120 Hz. What is the phalu4wt b m5,k94h kwxa3se 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 i)uzy + r3x8ped0(5 0b gwg57okbnwkcn f a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected i 7pgcx g0 w835oz0k 5yrwduen b(+nk)bn 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 consistdw9 6l.fc8 ls i7p4sgi1va;rus of a 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 12 pvcg8.7i;ldu1 as lfs9 rwi460-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 capaci7 i96en)u7ci ,pkvqq /4e6ip4ybug h ztor of capacitive reactance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60c6k i /6)4vu euzpeq47nbp,ig7 q 9iyh-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 R/ccx+px9 do 5uLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H induc uoc p5/xd9x+ctor, 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 k cy1 s/y/bb2nseries with a 500-W resistor for a phase angle of/y1y c2/bkbs n $40^{\circ}$ 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 = 105mutm/san;m 0 .0 mF. At what frequency an/m5 smt;u 0mshould the circuit be driven in order 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 with 12.0 W resistance,11qc1*z t(i kb8xku by1l)1ypsh pkj) 15.0 W inductive reactancbppk181zt1)yc)1 *hx sjyiqu k1l( bke, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power supply?

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136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an AC circuit is -ro p ae2sie.*ugq92zny ,uyi:,td6ftr (oe 2$63^{\circ}$. 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 impedancz9c,lqv ;x tu9e of 60 W and a resistance of 30 W. What isx,tzu9q9cl; v the power factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor for a series RLC circuit containing a 50-W resisto) -jv0cy( mk,tzteskq x /oc95r, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz 90(v/-kcze)mjo xyt,t5kqcspower 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 capaawa a7wiyq:t6:3/ a8gr7s db;t. cccecitor and a 15-mH coil in series?c :738:wst/ q7radwba g cciyae.a;6t

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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 yl+i)h: dd-fv uc ugous.3o1, 4.7-mF capacitor for a resonant frequency of 10 k-o3 udif+h.v: c)u 1odgy,ul sHz?

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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 ;*1ia)q*enraeo c j-xfvp+ i: series with a 3.7-mH inductor for a resonant frequency of 1*xacon j+:-; *ie )iar vfeq1p000 Hz?

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142#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor must be placed in series with a 30-W reszgc-z/k9khe*tk+i e 5 istor and a 40-mH coil if the resonant frequency of the circuit is to be kez/* ke9c-zk +tgh5i1000 Hz?

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