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习题练习:Physics Unit21: Electromagnetic Induction & Faraday's Law



 作者: admin   总分: 142分  得分: _____________

答题人: 匿名未登录  开始时间: 22年08月20日 21:29  切换到: 整卷模式

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1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following are units of magnetic flg3d ruz(fx-yy zx3q1 6ux 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 induct,y 1xiiy3-ygja (t3ueion 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 vz 1*wd6y3hparoduces what kind of change on thp yadzh v163*we induced $emf$, assuming all other factors remain constant?

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4#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the strength of the magnetic field through a loop of wire pro7 p1zm xv1v/6t 9ykfrvduces what kind of change on the inducz7v vr /x6y mf91kp1tved $emf$, 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 chj9 q+unah(sjar07y j8 ange on the induced 8rna9 +jayqj 7h(jsu0$emf$, 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 fsxm(n.d rrw*d(m 3n +sc z6l15na 4fuhrom a magnetic 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 an- gm6 re,.wogv induced current in a conductor will be that which tends to produce which of the following effeeo.r, mg -6gwvcts?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A bar magnet is l+ui3t4kew.v8mj ;/ce -n rw*btv5wvnp)g4p held above its center with-jemt. )r pulng5bwtvpvi v;w4*+/3 n4c8ek w its north pole pointing down. The stationary magnet induces (when viewed from above)

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on ac 57uuctq g1.e horizontal table. A bar magnet is held above its center with its north pole p7c1cqg5et. u uointing 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 topg r;8l (kpqs d*/vgdwnw)7j.e in a region where the magnetic field vector points straight up. The manqgd es7 wg .r8pv(j;*/lkdw)gnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field fades?

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11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a level table top inimuqgwf6/ m 7. a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the inducefw 6m7mig u.q/d 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 hlf.as(3mxgnv-7s yx bf: 5(msorizontal table top in a region where the magnetic field points straight down. The magnetic field disappears suddenly. Wxgsbns(f m: f573s.a ly (-vxmhen 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 lie - hcqa2*8ylqws on a horizontal table and carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either side of the wire. When viewed from above, the induced current c q2lc* whq-8ayircles

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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 of1eq j4-:3 ay d7dmyhis wire with the north pole entering first. As the north pole enters the wire, the induced currendq 3mjyi e7d-4a: 1hyst 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 mzap3bi)d 2k b.y0og9 axis whose direction can be varied. In a region where a uniform magnetickpmib 9)3do z ba.20yg field points straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be zero?

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16#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of wire is rotated at ri.ltwmavp8 xd (+g -7constant angular speed about an axis whose .( l+wiaprt7 v gx8md-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 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.59* s;kadf y9qu8jyf m
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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 thatw8vj s xa o/84ah3oes4nuwq52z3k 2bs 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. Tr0y-chpjv pn /k d 3)2trr9z8she $emf$ 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-wefdjcd kv *(o0 ybj4x*:st direction) is moved northward at constant veloci*4v:dc ok*0jjfxd (byty through a magnetic field that points 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 bar rotates at a constant angularn+fq gqo t8z)6 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 troiagh,, 8h3 ifansforms

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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 kx rhf9lmh (prdg25j:ut 62 3afrequency of the 3 ah(x9f2rkr m:5lugh t6jdp2 $emf$ 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 us2;fqqkx)ueqirx 0+ n 5ed 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 de.xh dmm*v*nc8 vice that

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27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the secondary coil contains more loops th( yogpt yb9t f((ar)b(an the primary coil typrfbbo( ( (tya9( g)then 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 cog :/avi2xo qh5ntains more loops than the secondary coil the5:vaog/hi q2xn it 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 i8 (xg.3c7ik3; vbio2tgy oxu cnput

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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,0hhig 2 .ubml2

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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 inq4spg jyq+m2.l*1mg a series to an ideal battery of constant terminal voltage. At the moment contact is mamp4.g 2m*jqyl+ga1sqde 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 to an ideal battery of con b)1tnehi gf :o6;x/urstant terminal voltage. At the moment conhe/i)fru:n; g6 ox 1bttact 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 inductance L andqlxqqr56x:g;0+pm-f o(1ec k 0lw+/ qt fhoud 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 a 1;. /u+vp )3 nwprrumdrhdzshbu7u 85nd 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 in m7;2 6cna7p/;nfz ny begha;jductor are connected in series to a battery. The time constant for the circuit represents the time required for the current ejg;fa mhab;7cp n2n7;6nz/y 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 serimwjw+8qwj l4 l gh:)m: qi-uv6es to a battery. The battery is suddenly removed from the circuit. The time constant for of the circuit represents the time required for the current to decrl4:wqmlj +q:w6v8uj g)miwh -ease 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 juc,wn848yeda v8dak6k ) n:;ceptt 4 the same units except:

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38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor is connected to an AC power supply. On this c;g j bs.zbr78fircuit, 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 myx f91ip 6bw;mo5e(fAC power supply. In this circuit, the current9ef(f 51mb miyo6 wp;x

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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 bybr6nz+)pa 3; ak i2tnj what factor when the frequency is tripled p+jb)2kn6t; rnaza3i ?

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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 inductive df 5b9no6b;mppk 9 zi-reactance of that indz oi6fpk99b n ;-5pbmductor

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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 kpgnn;;/ 13k)ie l;mqaw qh)md9v i4e an inductor approaches zero, the inductive reactanc))n p qg k 1we;vh4q/ in;;miak9e3ldme of that coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC8ffef/ r1j(gxw(9* ix 5sph bx power supply. In this circuit, the current fise (rghj98(xx1*/wpff5bx

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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 changesc(/q1h5l esx:d ro x+yflo o;* by what factor when the frequency isqoce+f1x5*l/o(rly hxd:s ; o tripled?

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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 ac-h 3 r*x2nrw6nv 3wjfvross a capacitor approaches zero, the capacitive reactan3jr *rw nhvf63 n2vx-wce of that capacitor

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46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle betweepcfwt;.ajz:ir k /5 kg x)l;x6n the voltages of the inductor and capacitor in a 5zwk/f;t axxr )pijc:;.k g6l RLC 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 circuin tf2 m.i(mc2jt 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. Thi.0m ze1 vxnw( hi55ja yr/)vhe impedance of the circuit increases if R increases. When is this statement true?1h y/ 5rvv5x a.i0jn(z)hiwem

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49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuqa vn 96defd;4it. The 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 incrg706kz1r+1t-wij ip grv. ca-k e zfo*eases 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 cy;n xv tw4ip kr0li4c gv9*+/vapacitance both double in an LRC series circuit, the resonant frequency of that circuiki/p9vc4 iv+* rg;0wy4vnxtlt 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 drivegv1bq-xvtk(yb f8b)b4 8 2mqvn by an AC applied voltage. At resonance,

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53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Resonance in a series RLC circuit ob 5y3ftb8*dg kccurs 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 uumy 2l 5;/wnnnniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop aw/nl5mn 2;nuynd 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 magnetvagzo 5ket29:mz- ex9jm1kjz7 ,hkg2ic field of 0.20 T. Find the magnetic flux through the loop when the plane of thj295x ozzzhe9 2tg7-mkemagk j1 , k:ve 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 magnetf gdjj88bes+s*i2w u 4ic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are at an an+d8*4suj iw8gfeb 2js gle 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 reducedwb7:c4wwb g,urltd.l)(cd3 m qs h zj;6; :jjd 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 fromg+ gcq6w) kdr+ $4.0 \times 10^{-5} \; Wb$ 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 sidesmz 88 (xyseb,ri2o: fw 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. Ifs8z m(8 r iox,b:fwey2 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 an area r0p7:x opyz (g*n l.i0my, pwaof $0.40 \; m^{2}$ 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 arg7wct9gnt, 15tepwko8vd* o7ea $0.20 \; m^{2}$ 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 sn;hhx,ex g;;5sqoqq 5 pan of 60 m flies horizontally at a location where the downward componen gq; x;5x5,qo;qhenh st of the Earth's magnetic field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal b ;n6j .cdkska avtjunh(8 +6w;ar that is 2.0 m long rotates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while in a constant magne;jav ja(w8snt .khkc;66 +n dutic 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 hagmw-,2r(q1axse/ j y gs 50 loops 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 consist0l*hnmd 0qe3i y1*k czs of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 rectangul r0pedjyewhwd 87 x;7)ar loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is per8hewde7x wy rj 0pd;7)pendicular 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 owby3f :,vcs2 if 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 ACuo :n ,a8s9mktmofo /7 generator with an output of 12 V maximum when rotated at 60 Hz. om9a ,k/n87sfou :omt 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 generator with a maxo.wfnod9t 0- iimum $emf$ 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.i30 f 0p qk;tyy.uxa)e00 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. The motor operates on *0dlqac, zy8i 120 V AC, and when ,*l cd8iqay0zrunning at full speed it generates a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 qfp p:jp 7a*oe *7j:2i(mnbxc W is connected to a 24-V power supply. Thec7x7*anpp bi( : *2 qep:jjomf operating 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 resistance 6.0 W is connected to a 24-V power suppl hm2o2 km7boc;y. The operating current is 1.0 A at f 7m2omkbhc;2o ull 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 connectep4j8 q v newfc .duj,0kt9i;3fd to a 24-V power supply. The operating current isp 0wqf4k9d ntv ejj; 8c3.,iuf 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 reddxso +);dqd1l*3 xqgt uce 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 transform4qaf x sjiw1hdp:+y73er causes 14 A to flow in the secondary. How many turns+xs w47i q:d3hy1j afp 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 p*i5a0brs q.+ (pmtjl h 5vrj/4y2ormzrimary if the 24-V secondary has 100 turnvj .mjlrta5m4b qh/s(zpy5i*r +0 r2os?

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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 ej lrljk7zf+ooxcn6 4t ny *e+6,e ma8z;0d0hand a 2000-turn secondary coil. If the current in the secondary is 3.0 l6+me; f0 rz*,tno j+lch8z7ojnde 4ayk6x 0eA, 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% efficiency,(j .:9 3hf-axvtsqzzf how many amps at 24 V can :jvtfqzh9a.(3f x s-z 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 s hu. oq(4uo:wvign transformer provides 7500 V at 10.0 mA. The primary coil operates onh 4o:w(u .vquo 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 prvtiusgg-s)-vi ; f-d.pe 3:1jfwk2jwimary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is w-.-fg3 f1j)k isp tds w2iv-gj;u :evpresent 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 tuspgkok q ; up(geh;5uw.d7 -i:rns on its secondary coil. If 120 V at 2.0 A is applied to the pipp.ue-qgk 5k ;h:7u g;s(w odrimary, 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 secondary haso khv.v31u+ stv yyk.gm+w6t1 200 turns. If the input current 6+ vtm+h1w .tykygovvk u1.s3at the primary is 100 A, we can expect the output current at the secondary to be

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85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has 200 9-9;- kd6sy 3kavmm m;bl 5fqykympw9turns. If the input voltage to the primary is 100 V, we can expectk9v ;96blf ks-3y myqym5ap9mk d-mw; 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 secondarl.nyt4 x6z l/u d:3xdwy has 200 turns. If the power input to the primary x/ dw.6dxly4 zu3t ln: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 ofeiaf.p ds .o4) current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the numd.soipa . e4f)ber 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 isnx()7x k.tcuq-;.4rp ssu kucxk) 3fp usually stepped up to 4500 V by a transformer and transmitted through a power line of total re7 qsx-p ; (prkcu )3 cst4kf.nu.)xkuxsistance 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. The voltage iefwg6 ra1t wc8h7(bx-;tz ;g xs usually stepped up to 4500 V by a transformer and transmitted through a power line of totabr8f 1 exg6 wc;z-ahw(g;xtt7l resistance 1.0 W. Find the percentage power lost in the transmission line if the voltage is not stepped up.

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90#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long has a totalvz9r4 3bgicn 8 resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmissio9 g bv348cznirn 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 of 0.605 pu14*3vxiieea;:p zz neck+k2iwm 2 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 withk53 ce ik2xpw4u*;npizm1 zevi+a :e2 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 transmitteds5v rfqe2kg5r)p bv/- down a 6-W line at 1000 V. How much less power would be lost if the power were transmitted at 3000 V ins 5qe rgfkvv/r-s52b)ptead 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 transmiqtl nkoa 2mco*/95x. itted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a transformer if the power loss in transmission is not to exceed 0.qnilo*2xmc9. oa tk /5010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. How much energy is stored in the 00 tg(u;gigvst87k emcoil's magnetic tg0e8 su; i7(gtkm0gvfield?

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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 c)enk 5 9rri 18 idsifwf ,i2nupt+ogii2jb91 8ontains a 6.0-W resistor and an 18-H inductor. What is this circuit's i+k15rgnfp ubdr siotj9ei)8fi1w n8i 292i,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 circ+d6p9r7mkyp8 ke d: /mwyw.hhuit 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 outlet. What is t1oh+vgdcnv 5 hmxkr18q l,6 s;*tw2khhe 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 ty-cvl e0a(cy cy(ir0 6he resistance of the lamplyvr(-y 0a0ceyic(c6?

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99#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. y 9k0ufti)x -1tf.aslWhat is the peak curre-i us 9xft.fl0t)1ayknt through the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120 b e*c/zpws9fjfkf)c 0n .knyj4;xd),;eevs/ -V ac power supply. What is the power dissipated in tkjf yj zk;,;*fxncf/n4sp9w des/0be). e)cvhe 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 resistor is x,sg.w1;uhoc*8vo 1m kk*pvu g2 m) ll$I = 0.80 \sin (240 t)$. What is the rms current?

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102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor is 1w1sy-g .xxj ,n9t puk$I = 0.80 \sin (240 t)$. 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 c:*nnvo ,*cn8 vijja /resistor is $I = 0.80 \sin (240 t)$. How much power on average is dissipated in the resistor?

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104#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the reactance of a 1.0-mH inductor atie)1m1u1t7qpg mw q * 4jwwa/z .l.abg 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 inductiv nb* gr(v*fshi3o 2qx;,)dmb ae reactance 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 *kbysdp +waebq /iux 17dq09.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 nece+l*ysfyxku*koyw1+4 y9t kg 5tms )e5ssary 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 kt-d/nw.vnpzy 7om;)m 7n6kwV AC at a frequency of 20 kHz is applied to6nnt w wpk;7/ m)7ozm.-kvd ny 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 .k x,rc,z, t0ivlv2vz110-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 xvx2 g8gsa -08vcqu95x9. bzrz .mryhof a 4.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is needed to have 50 W of capacitive reactance at 10 kH-k2 8l5 4z-a wudconfuz?

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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 120:29a7 nf;ksie(e0 e5 qar f1luzigry50 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 t/wdja7/q ye 8bj+x(k k 7ir;ephe capacitive reactance of a 0.010-mF capacitor be 100 Wjr 77pkaxqeb/e jw id8yk/+( ;?

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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 /yaw+yx68 5f sad+f9 ybpkj+v capacitor at 1000 Hz and 5.0 V?

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115#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the impedance of an ac series circuit with 12.0 W resistance, 1h9q obkccaw93(9 :hd h5.0 W inductive reactance, and 10.0 W capa9:hc3bhqd9o cwk(h a9citive reactance?

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116#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the total impedance at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-kjv+4bw2 n p3cm3cjkn 4b vp+w2F capacitor 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 10smx /2lb)is 2:(xlyw36tw a l6j0ia ww0-W resistor, 20-mH coil, and 1.0-mF c:x) aw 0m/2l(a6xy3w 2ls 6isl wwtbjiapacitor 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 wit6vl4jsvl 8w: fmga3 6th a 20-mH inductor, what is the impedancawmf8 4tl6 3l:jgs6vve at 1000 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connecrd7.4q:wmr l mixt3) yr;xt;eted in series with a 20-mH inductor, what is the phase angle 3w.;x;m 7imtr4q)edyt lx: r rat 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 needewt 9-ekx we p4ht1j9(e f5k2f,enrnr4d in a series circuit with a 20-mH coil and 1.0-mF capacitor for a total impef( rkhwntek1 f, -2j9we 5ee p9tn4r4xdance of 100 W at 1500 Hz?

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121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed in series with a 100-s4b - (v;e dks:hf9d-ku /ojljqo6ql 4W resistor and 15-mH coil to get a total impedance-9eslbjhodvq4 fd4 -kks u(ol6;q/:j 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 5000 H4g+ ed1ylsmmke7m39/ u1+a+v oc zrcpz for a totale3d17 p rysvc/u1g9m4+ zmoa+mcl+ek 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/dii3, sr1thj o r51iq with a 100-kW resistor at 1.0-MHz for a total impedanc11hs5, tdiqj3 r/roii 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 pn1 1y)g5igg7 z4iljqseries with a 20-mF capacitor. What is the impedance at 1g )114pygiigzq5 n7j l000 Hz?

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125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-m l8rsonp +z/z*6e,2 iy i7yfnfF capacitor at 1.0 kHz for a total impedance of 45 W?ysf7zn,rn8*yi f6l ope 2i+z/

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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 i sde)lp,7 lyq.n series with a 10-mF capacitor at 1.0 kHz for a phasde.sy lp7) ql,e angle of $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 30-W resistor at 1.0 kHz for a toft-1 ;i usaf*joja h,:taloff t h*a:ji-, u;aj1s impedance 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 seriesq(0e6ny /p mm2h tkxm7fl-a8s with a 100-mF capacitor at 120 Hz. What is the phase8 q7p-m/f2hetlmn6y 0xkmas( 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, 20-mH coil, and oi1thel / c;p3;lb 1js1.0-mF cap;pls;c31iol1hj bte/acitor are connected in series?

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130#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit consists of a 100-W resistor, a 10.0-mF capacitor, am0,d3ozb6ds6 7n h yl8m*vw tqnd a 0.350-H inductor. The circuit is connectez80v,nmwdtqs l*6 6bhydmo3 7d 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 fa32yl*s 4nndz prk+-7hd u*v30 W, and an inductor of inductive reactance 30 W are connectedns-l4 +k dvd u*3hzap7y2nrf* in series to a 110-V, 60-Hz power source. What current flows in this circuit?

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132#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle 5 gnrrv)i9pre5o2l f ,for a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-2goelp5,rv 59rrf )i nHz 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 wi 7a3oglcisi5* th a 500-W resistor for a phase angle of ic7olisag3*5$40^{\circ}$ 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 = 2e7 ti2cwxi ah. +sr;/o0.0 W, L = 200-mH, C = 10.0 mF. At what frequency should th;i xt/.+ 2cw 7haoisere 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 resistan68b 9xo4o:+h iridpu jce, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the cu 8+iboi:6x9dor4 pjhircuit 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 0 *yk,x1*agwt-dvj ro0-xsg0kl d2g qAC circuit is $63^{\circ}$. What is the power factor?

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137#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ac series circuit has an impedance of 60 W and a resisjv t8cf1q 8su3tance of 30 W. What is the power factorsvtfu8q8j 13 c?

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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 seriexz :ty4fs/5 baq- r0nrnprk 02s RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz power tan/: syz04xp-q 05rf rkb rn2supply?

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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 cap4t pc.9xxoyo8/ovq-r +z 0ekkf;ohk : acitor and a 15-mH coil in series?k+yhox4fq;x /. czp- t 9kv0:ork o8oe

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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 im jto w/ ao6ii01z7h0)z:hncya /m4ct n series with a 4.7-mF capacitor for a resonant frequenc jac06mi0ot chz/mo h:)/7zt na4iy1wy 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 nes) dn:wqk)0fe ku lyr5 x8 sjks;6+f+qeded in series with a 3.7-mH inductor for a resonant frequency of 1000 Hzf+j + s kfkk8rdy:e0w)sq65x;ql)su n?

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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 l2bvokf(a 5nq bglg7hu6q8 8, 30-W resistor and a 40-mH coil if the resonant frequency of the circuit is to be 1000n8b ( 8hoa2,ul 6bggqqkfv75l Hz?

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