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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 u4quj2uht2ubwv64 hcir 8jxm,hp;( 2hnits 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 stapf +-k /5j/tu dljrlp8tes that the $emf$ induced in a loop of wire is proportional to

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3#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the number of loops of wire in a coil produces whav21i68,+nekgwo 7w;u qw 6vus1/ y q*ns srkift kind of change on the in qes /s*+;wk yw6u 6nwgniv v17o qs81ifrku,2duced $emf$, 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 pro.u)hp ;3 rgovjra-yid9k0,x6y-jy d mduces what kind of 0p grd6j-ha.uy3d9vyy i-ro;),x k jm 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 l9( h dt:r y(huip-*yqqoop of wire produces what kind of change on the inducedy9 q-hiur:tq(y p*(hd $emf$, 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 kxochvqpd ,e *u-7 o80field an $emf$ is induced in the coil causing a current to flow within the coil. This current interacts with the magnetic field producing a force which

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7#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  According to Lenz's law, the direction of an induced current in a con 1 ufjh-7ys*msnub 9p7l7z.qdductor will be that whic.p1q7u-7ys u*zbh7m9s nf ldjh 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 horizont 7j w41usa c p;yx)uno68kvuz7al table. A bar magnet is held above its center with its north pole pointing do a;py7 junszk6uv 7cuw8)o1x 4wn. The stationary magnet induces (when viewed from above)

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9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizont y mwcywa8w fc2 :(m5q1;mzwiygw -71ual table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magn(:m1 yc2ugqfm5-m w1iyay7wwwzwc ;8et 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 wher 9j0drcu hp+5nuq. o)de the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from ou d hu09jdn)cqp. +5rabove, 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 l75 aibvz cwtqf+*u5b*w;a cb7 evel table top in a region where the magnetic field vector points w *wf77uacc 5ibaqbv;t*+ zb5 straight 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 region where the uw h 94j.(- ybiyg.gdlmagnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, what is the direction of the induced current in this co4.b.yd uhyj i-w(9l ggil as the field disappears?

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A long straight wire lies on a horizontal table cy6x2 7j*dvx jand carries an ever-increasing current northward. Two coils of wire lie flat on the table, one on either side of the wire. Whey 7 2vjxdcxj6*n 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 wir 7;i u28kjnmzbe with the north pole entering first. As the north pole enters the wire, the induced current will be (as viewed 8nu;mibjz k72 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 -c4ntclc0 zk5v:xm9 ip gvbse4 ad8su 3.av8,about an axis whose directis.a3v-4m i zgb:0, tvaccl 4 u5sp8e8c9vkxdnon 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 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 spjmc kbc-u. xh+wp*g9;eed about an axis whose direction can be varied. In a region where a uniform magnetic field points straig+*mw kj-h c xgc9.b;upht down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be a maximum?

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17#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Faraday's law.x+nn a1:;0fyw,0dxk hti 6giq
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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 ;d9sc-imc dj-that 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 magnetig gls)c (qiol; s nn.e,xq19r5c field. The $emf$ produced in the wire depends on

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21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal rod (oriented in the east-west direction) is moved nort5z vp8kejr;j 5y ,mh47niw:y dhward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potential induwep r8:5 7mh yjjdyiz4n,;k5vced 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 z 5xio y58e*ovrotates 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 q5weis9:ngctjp b- h :sl97c)8vu7g ttransforms

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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. Th 42t gtyr i2*t0wfe2 w2gr8g5:bkuvf pe frequency of th:f 2 bu gger25k24y*tp08i2 vgwf wtrte $emf$ 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 dmfmd15zf oz3;su k ,(yevice used to

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26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A transformer is a d c+r z6yu;h92lvbcw2x evice 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 moreit vembd g22(r 0hyx*, loops than the primary coilt 0xdyrigv, m*22b e(h 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 contains more loops than the secondary cofmy mcr u3 m 2(7,9cko1wwabv2hfzb7(il then w(c2 23fuw rm1(bmhmf9, v b7caozk7y 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 powevb 346.chgrky nz y9q5r input

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30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a given LC resonant circuit,5g.s;p blj.pk

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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 n8ffa;i*tzb:(7wc yg 3s l4wrus3 u p(au5)v yconnected in series to an ideal battery of constant ter7i s ugyc3wf 8 f(zwuy rt)av:3;(unbls5a4p*minal 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 inductor are connected in series to an ideal battery ouyw1:v-qg2u q f consta q-gq u:u1w2vynt terminal voltage. At the 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 inductance L and resistance R2spu+dr+ whg- 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 resicv lr na,p3t2- uci;2wstance 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 ar 6eoc8 ct)su)q.ta0 pse connected in series to a battery. The time constant for the circuit represents the time required for the ecs 0)ac6o )tu.stqp8 current to reach

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a battery. The a)lnui.5 g9yu jc9t -vbattery is suddenly removed from the circuit. -) u95y 9jgacnlutiv. 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 sa o qr.+atv;re6me 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 supphzu8si u9a swy t,-v8(ly. 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 circuit, the curr 1v goirql2+e;eng o12rlvi+qe; t

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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 changesae30ev 7zth7 .hcep 0bi9;)ntnc/q puv2f nu 8 by what factor when the frequenc) ipnceb3v9 u . e 7n/h zhvfqca;0tu7t0pne82y is 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 ack rf8mc7ii:goz.9b a0ross an inductor is doubled, the inductive reactance of th :07 ka89gofizbmr .icat 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 approac lg/n;*hd-haw hes zero, the inductive reactance of thhn dhlagw/*-;at coil

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43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A pure capacitor is connected to an AC power supply. In this circuit, the ce-nn, *xz ac5psl:c 3vurrentlnex:3vap zsc-,n c5 *

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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 chang hz6q8;*dj zoeag+0 p)qvh i+1alqop8es by what factor when the frequency is tr1haaq) phd6 8q8 vlq jo;+gzepi o*z0+ipled?

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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 capt7 g/ v1(d1pbwam4 boh, jcid;acitor approaches zero, the capacit41 icbb(mdv w/hpt gdo;, 71jaive reactance of that capacitor

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46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle between the voltages of the inkejd19p:tbtb - hh1y v4els7 jldv+ ,2ductor and capacitor in a RLC 7kv9- +b12dvh1 etj j lld:hbptsye,4series 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, zp4ub7bf60/ 9l mkodj*ahst 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 thefye,r3zq sb6r;ez bd *s0,. ui circuit increases if R increases. When is this bfz,3;d eb6iu *sz r0sy,q .restatement 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 incgwm**2 4pe aijreases 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 i r k,5uv(acdz6mpedance of the circuit 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 circuhl k hux0.u3b:; b:gq7dfdrr n*g//)u(xc ghdit, the resonant frequency of that circg*3hfgdu:n(;rq.d b 07ukx /)cr h lbg hx:ud/uit 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+ql/)el eiwb.5p uyqg6lf:l, 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 occurs wheqzi bgbfrc yy7w4akx;3873g ,n

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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 rad1rnwh51ko7w,rw :x r vius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the mavorwr,1r7n:5w h1kx wgnetic flux through the loop when the plane of the loop and the magnetic field vector are parallel.

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotarr.m-taz)1zt l ,dt b-f w)aiv;- :dmvting in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and t ral dvf-wt)mdai v;)tm: ., -zz1t-brhe 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 ./sa y:;c ynf:l7soqc magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vecy; /cyc lfs:7s:oa.n qtor 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 i gv4/z13ie+:,mr a qnodzt+4c s2kn6ar x8ararea of an adjustable 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 chql5m3rrr vh zaxq;)3( anges 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- u8g)hatsg)dx-d7 dv on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the average8xg7t gv-suhd d ad)-) 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 of ka m6mmhc4; pqpcn 17q-v09m y$0.40 \; m^{2}$ 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 l1r4jy ksd1) warea $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span of 60 m flies horizontally at a location where th9tlp;qc zh7(smt7q: lqhjf +4 e d+hq 7 qf49mtstl7 j( pzcl:qh;ownward component of the Earth's magnetic field is $6.0 \times 10^{-5} \; T$. Find the magnitude of the induced $emf$ between the tips of the wings when the speed of the plane is 225 m/s.

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64#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A horizontal metal bar that is 2.0 m long rotates at a constant anru7t ivw*6pik l5z0 kxs1/n6n gular velocity of 2.0 rad/s7p0 rl*6vik x n51nts6u/wi zk about 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 loops and a crosu p-6m)4gr/x 2gwxq i fr;;hlls-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 yxqi- ri.n r +:kp1y.oarea $0.090 \; m^{2}$ 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 hryq*ax h l)39is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the lo yr3 9lah*h)xqng side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular to the axis of rotation, what will be the maximum output voltage of this generator?

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68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns of wire o5y m9 l+xl cfmgydv n+xd6. 4vje0tp--f 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 constructd7.snr zte+a- a simple AC generator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the ar7er.-tz nd+ saea 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 generatogj4oc ly48hu :r 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 a resistance of 6.00 W. The motor operates on fy(e ib6rcth,4e6 c tr. .ihnaqut:(*$120 \; V$ 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 6 s ko+lu(2 vbi6avco(motor operates on 120 V AC, and when running at full speed it generate 6vo +(o6 (cublkasiv2s a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

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73#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V powojxoezkmuz b/ / hd :f9(.7g19*rtmdmer supply. The opeduob zht: ke7of*9/jgxmz9.r1d/m m(rating 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 :04wpymlv0waa:mjx4 connected to a 24-V power supply. The operating current is 1.0 A at full speed. Wjl 0wma:4: 0 4wmpvxyahat 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 resista,g di 9hgth sww41h:.lhbzqd k)a2t/4nce 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A at full speed. What d . l1 ghda tqh :tw49h4)/,sh2kgibwzis 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 transformk 7xbcmh.0d- iwkq(g1 er 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-turn primary of a transformer causes 14 A to flow in+x pn2t viup2 htdi13yq85fi8 the secondary. How many turnd2ut3yp n58ptq82f x+ihii 1vs 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 )m1.b kkw.w pfin a 110-V primary if the 24-V secondary ha1w.kw m.fkb p)s 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-infhu1dzo3qj* mq(7wty0 r 1,turn secondary coil. If the current in the secondary is 3.0 A, what is the curqqmnf3u7,y j1d*owh z t(1i r0rent 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% effici-) *k lo*z+x+zkdept- esa69ck hxd o2ency, how man-zox2*p +9-otcd)+z*k x6ak l hesdek y 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 neko7ukv 6 5qq:bon sign transformer provides 7500 V at 10.0 mA. The primary coil operates qk5bk7uqo:6 v on 120 V. What does the primary draw?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primrrdekrurw)j 2 , ;+y5bary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is prerrudwk+, )r br2 ;ey5jsent 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 coilqs c ,+-q,dash ::pahw.kbh(d and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, whatq s,a :dc:.hdha(q-sbph+,w k 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 has 200 tufxnydvv8 m.,95j z0x yrns. If the input current at the primary is 100 A, we can e,vj mx 9zv8df0xny5y.xpect 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 turg;b l/n80eybs9 mds , wn7icg*ns and its secondary has 200 turns. If the input voltage to the primary is 100 V, we canbl0wm,8 n7 sgync/*b i;sg ed9 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 turnsbdlhil:w 4, 1a and its secondary has 200 turns. If the power input toi:l1d, 4wlhb a 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 v7ts ijlae4 t 2zz/q*o8oltage is usually stepped up to 4500 V by a transformer and transmitted through a pozo8a/7iztqsej 2 t l4*wer 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 p bp2sn;nw6sjwvf 702 120 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 percentage power lost in the bnnp2s wwjpv s;2076ftransmission 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 bjy 02s4j3s kjA of current at 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the percentyjj2b 4sj30ksage 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 0.6bsnlb*: ,eg .q0 W. A generator produces 100 V at 70 A. In order to reduce enng.es:, b lb*qergy 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 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 0.60 W. A gen2agn:nohs. z*erator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the vol:*gnhznoa s. 2tage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is lost when the transformer is used?

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92#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  100 kW is transmitted down a 6-W line at 1000 V. How much less p8t-bnbu86jq7+z:6fwtn l v v vqjv )5iower would be lost if the power were transmitted at 3nn 5 uv)7vj+z 6w fvbqlv qttbi688j-:000 V instead of at 1000 V?

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93#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The output of a generator is 440 V at 20 A. It is to be transmitted on 3 h7 (dxenbo 063mz;j9mqhqjh a line with resistance of 0.60 W. To what voltage must the generator output be stepped up w6jh0dj ;xnbm9ho( qqm3 ehz7 3ith 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 eyzu)p/ h1gv )dnergy is stored in the coil's mayg)/d1v hu pz)gnetic field?

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95#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A simple RL circuit contains a 6.0-W resistor and an 1x/ irn gqc pj-9v8ks/,co16j q8-H inductor. What is this circuit's time constajcr,k6ixc1sn jp 9q//gvq-o8nt?

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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 voltage29ob.u4 v jdg8id wwvtim0 v6: in an AC circuit 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 ahecx0b .)9bxu+kobe:iy c :u, 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 la26u 1the6u ;kpecmqvk 8(f0mam k mv8mtc ef6pk2u06;a1ehu( qp?

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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 ppa.l ts vf; 74svwo))vower supply. What is the peak current th7lwf.4v v;ps)t sao) vrough the resistor?

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100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected to a 120-V ac power supply. What is the powetl 07u7 xrsyo.r dissipatedl s0xu7r.t7oy in the resistor?

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101#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 5rzm2fnkizi 8e;-v 58m0-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 50e m;dx/gjsn4 8-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 9p;t4ckj 7e77nsp mfw 50-W 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 induc2yudd0z m. o;ttor at 60 Hz?

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105#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the inductive reayj )4 qvmv-*npc0d 5wuctance 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 reactanc /-lf(x bx u2+wssny7q4cvq5be?

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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 157rx7iw0 y-k1fa 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 in-ls: *f uy1lts6)cop qd)lw/rductor when 120 V AC at a frequency of 20 kHz is applied to wf t) 6sq-)lu/oly*1cdsrp:l 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; fi-t5xp8xthegkp) 7ji1wbnla h)p; s6 :w 4w-mH coil due to a 110-V, 60.0 Hz source?

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110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitivn5 xlfz k.0.uge reactance 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 isf9/j.:vlw-bqx4c.zbjsxfjp* 9it m ; needed to have 50 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 capacitor have 6p7nlpw qn-/v 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 reactt-:iahqmt4emp5 wv6 dz 4h 3en177n awance of a 0.010-mF capacitor be 100 W? 5a37vn:ewqd4t 17p -th4 hwamz6nmie

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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 capac l:b27 b;n+cbffl(k6 r-ql civj5e y6oitor 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, 15.0 W ih d*d)e9zod n/q x:x.hnductive reactance, az:o /nhe9d.hdx*q) d xnd 10.0 W capacitive reactance?

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116#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the total impedance at 1500 Hz)uo z-ot 7w.eez 6mr4r if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected in sew)e.6 mo-eurorzt4 7 zries?

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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, 20-mH coil, and 1.0-(jgy50gahrn0 g 7y,u6 ox-vbqmF capa0uygq,x r6-g avgjh yo 05n7(bcitor 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- , w4p*kuvwoc connected in series with a 20-mH inductor, what is the impedance at pwwv - ,uc*4ok1000 Hz?

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119#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-mH inductor, what is the r;fvi19un7hn phase angle at 1000 Hz?9rn; 7invfh1u

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120#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in a series circuit with a 20-mH coil and 1.r(6sy u9a cwq*ukk4e8ai f6n .j5n,e pga1d5j0-mF capacitor for a total impedance of 100 W at 1500 Hz s56 jaupcuifwd ,ege4k81a nk nj. r56a9*(yq?

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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 ser4 ( 7aueh/ztkz 04pcbries with a 100-W resistor and 15-mH coil to bae47 (p0h/ck tr zz4uget 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 serimina, 724(kgsow52xtmcih.*p m agi, es with a 450-mH inductor at 5000 Hz for a totalwx,a(khio2mgit a.*4,psnicm m7g 25 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 z7(y x3qfcu: eyc( op3f0imx.be put in series with a 100-kW resistor at 1.0-MHz for a total impedance of 1e zcxu73xq(f.fo (3yiy:p0 m c50 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 capacitorcx7)q e1 0r ql4yp5s4hwhk ev*. What is the impedance aqve ryhs44lkq)h5 017ecp *wx t 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 s pus0 +5sff*mneries with a 10-mF capacitor at 1.0 kHz for a total impedance of 45 Wps+ f0f5 usnm*?

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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 ser1gd7 .d8icgsp0v gk0u ies with a 10-mF capacitor at 1.0 kHz for a phase angleg k is0c.g8 vg71d0dpu 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 k4 :bdwqr(76n vq 9egdeHz for a total impedance of 454d:ebq6 r7gv9(d wnq e W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 120 Hz jw9xvvu3f *vcty; -1l. What is the phase a19*-3v y;ctwvvfxj lu ngle?

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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 105q( jn ,.xzy y,cg1oyj0-W resistor, 20-mH coil, and 1.0-mF capacitor arej5, 1zyn,gx c.ojy y(q 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 capacitobkm6 va 7x/q(1mwec1c r, and a 0.350-H inductor. Tb1 w (acmq 1/7xkce6mvhe circuit is connected to a 120-V, 60-Hz power supply. What is the rms current in the circuit?

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131#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistance of 55 W, a 4 k0ew1wa;zs)0b* ; kivhyn jdcapacitor of capacitive reactance 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 ci e0z;bny4*d0h) aj1 wv s;kiwkrcuit?

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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 an 5b4:r+fqi92s-se nuupda o8 ngle for a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.uq2n-n ao9b s5s:ui ed84pr+f45-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 5, aldbxc-h, )mi1 )xwr00-W resistor for a phase angle of crh )xbax ,-,dm)lwi1$40^{\circ}$ 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, Lfecv+ynmvs1/d -g9tx4 t u*6e = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order me+tvs 1u-6tn*d xge4vcf9 /yto 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 cjm(5o9jnl2 kio1 -ikmircuit with 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power suppll-kmo1 njim2i9jko(5 y?

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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 rqft 5 lp5fjsz9gu-y x.qy8h)9n 2 0beis $63^{\circ}$. 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 9l0 cc y4cfr0u3bd*k a30 W. What is the pok0b94dulrycfcc 0a* 3wer 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 resistog4 ivk(;njr- w)2jtkw fu5 e3ar, a 10-mF capacitor, 2wajwen4 vgu)jt (f3kr;-5k i and a 0.45-H inductor, 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-.(8ge7bbngz wmF capacitor and a 15-mH coil in series? (bn8z.weg7 bg

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is nee 8+2 slb;1y remkrt8qyded in series with a 4.7-mF capacitor for a resonant frequency of st2e;rkm88y +yqlbr 1 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 3.7-8q, /rgp3wd cro)v9i imH inductor for a resonant frequency ov )i qpo9g,iw/ drcr38f 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 must be placed in series with a 30-W resistor and a 40t4349zvox;b1 q4 ijgut q8lnl-mH coil if the resonant frequency of the circuit is to be 104gl oti 8qzlu 4nxv14 ;tq9bj300 Hz?

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