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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 flux e2pidf*ni 4zqpy( 7uz* xcept

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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 states that the vt 3x*0tzzs0o$emf$ 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 oj7wrlmxdaoqe2m 5-: * f loops of wire in a coil produces what kind of change on the inddx5wrma2l7e o: q -*mjuced $emf$, 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 t*71 k06k.pq 9zzytphkx :.t. iwnxloe he magnetic field through a loop of wire produces what kind of cha1 .o.pzkkxyxwe.hql 9k 0n7p:6i tzt* nge 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 kind of changc4:yb ,ej9ift e on the induc eib:tf,9yj c4ed $emf$, 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 magdm byst0+j0s 3netic 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-+6kq8 0nl,eogdq ffj , the direction of an induced current in a conductor will be that which tends to produce whifnfoj e 6q +kq08ldg,-ch 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 )xxt go1ii v49/o igh/horizontal table. A bar magnet is held above its center with its north pole pointing ogxit1 / i9/ivox)hg 4down. 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 horizontal table. A bar magnet is held above it 2yne ; /j73npuk,abpns center with its north pole pointing down, and released. As it approaches the coil, the falling magnet induces (when viewed from above)a;nkp,un jp7e /bn2y 3

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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 tablmj2 d p+*gsx7oe top in a region where the magnetic field vector poinpojd+g m7xs 2*ts straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the induced current in this coil as the field 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 huet 8c e.eozkre;224a level table top in a region where the magnetic field vector points straight upckr2h4. 2 ueez o;8ete. 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 magnetic fvh04 +d(:.yg m nvqrg8hhe l-aield points straight down. The magnetic field disappears suddenly. When viewed from above, avdq-8mnh 0 4h.v(:y+ hglg rewhat is the direction of the induced current in this coil as the field disappears?

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13#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A long straight wire lies on a horizontal table and carriesyo /x o/k3yan:y+5mdu pm3 g0w 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 circles+wmnay/ 30:mo5 3d/xyogpku y

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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 ox+rf6f8 w6r 2ckx5,oj)ttzb c f wire with the north pole entering first. As the north pole enters the wire, the induced current will be (as w+xxro zc,6 k2t5f)j6cb8frtviewed 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 axis whs;lk xek,:oj) lf/4tpose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of tej,kf;/l4 o klpx)s:t he 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 2 nyluyp.; pth,qmy3;lwl( h, constant angular 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 of the loo,y3t;upym(h ,lhw ;l 2yn.plq p'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. 2.u gin0gdws2wx3p3s4 ifh :lp:flt*
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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 an0n aji ex,v8z85cd j1e $emf$ 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 fi ,djapy(o.i9seld. 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 dirrj;f:*mn5r l a5rp fh5ection) is moved northward at constant velocity through a magnetic field that points straight down:;r phrf 5n55*jamrfl. 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 angulk vp5(+jc n-pnar 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 transfostwze(t;: (/(ysn4 bq,fb m t)aa) vrmrms

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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 thxyv2w5q t;3eta ;oa 8krough 60 revolutions each second. The frequency of the ;aq5wot 8 k;veax23ty $emf$ 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 devpk tu 2m*nah y2ca.e5/ice 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 devic:goq91x+ bfx (uavks )e 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 than the primarxh mz.txa*4jexpwx4j69u 4 ;wy coil then it mzx.*4pwj e tw9axjhxu; x464 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 pri8hrz uws/8, em5(wfizn3 cjb+5 l/mrvmary coil contains more loops than the secondary coil thj3w8wfs+(l/e miu nzhc8 ,rv5b m r/z5en 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 po3kewd-sz yn; 0wer 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 circu21bq kdo,nv1,jsjn +l it,

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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 seri*qkd v3d7jipkp h l6l)x6yd2( es to an ideal battery of constant terminal voltage. At the mo jv yil6()k26x3pphl dqdd7*kment 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 battp*+h bxb8do s((ul ch7 9ju9ytery of constant terminal voltage. At the moment contact is made with thebh+8u 9tsh9b(x dj7l(u pco*y battery, the voltage across the inductor is

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33#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resistance R is connectedshw2g3my. r6 t x7bml) 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 resistancexm4 e ;3n:ex,ntxm;oi R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

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35#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to -k 7uwp (7kwdha battery. The time constant for the circuit represenpwk77(w -kud hts the time required for the current to reach

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36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to a battery. The battbwgw1z 0 rczjxo/;m0ul 14qc;ery is suddenly removed from the circuit. The time cwmb c qz1 l/w4r;c0j1oxuz;0g onstant for of the circuit represents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the same unrqgz35kd+z eig7 b.8nits 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 e/r g: *9exx: v(vjtnkkewb ;;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 p9- rysgp+ h.1la vwt5wower supply. In this circuit, the current.val5wp9+-wr htsyg 1

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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 0; kzj3zq p1fcan ac circuit changes by what factor when the frequency is tripled? zf;q0p c1zjk3

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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 induhb yco cd230:hp ev im;+s;t0uctive react cphd0;i+c u3ysbohtv e2:0; mance 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 thet;xyro8jnv4 + AC voltage across an inductor approaches zero, the inductive re;jr+not48yxv actance 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 AC power supply. In this: f9mnkc +jph; circuit, the current:hnc9;k m+fpj

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactancep8 .3 mjg6bxb:nmtu p) in an ac circuit changes by what factor when the frequency is p)jg.m x8bu6nt3m :pb 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 across a capaciez7,-udj r0n utor approaches zero, the capaciti7rnjd0e- uzu, ve 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 voltagex5t0jzt m f1 -u6ps(lks of the inductor and capacitor in a RLC stmst( -0zl u5x16fkjp eries 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 circui .ivnum(p j 9ya/pd6e6t is defined as $\cos M = R/Z$, but the phase angle can also be calculated from .

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48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. The impedance of the circuit increases if R incr1dv6 (ktzs9xp q3* q(c15+x zgeyq xwreases. When is this st dxe3x pqzq5 9 sqv6(wkg 11cyr*x(+ztatement 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. Theam933jcjw td7 w3fo3s 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) fl8g4bbcsb ) impedance 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 j22bw4y7zr ;jkkbr5)vjsb u) the capacitance both double in an LRC series circuit, the resonant frequency of trjr)7bj;j 2s ub)k 42vz5bykw hat circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is driven by an AC applied voltage. A, )rrs vlx s w+wksm2.eguu4/-t 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 7.du8-mv i-n1f h.5 mp zvpfcycircuit occurs when

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

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55#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform magnetic fillw:e 6j4f9cykw34xk 46mvf feld of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic fieldvwk f396l kex4:m4wf 4 6fyjlc 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 rstxs18d2f4iam r t r/ n,1pp1notating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the8 pp4nrsxnam/,f1 t1 ts dri12 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 0.1s3lcth)p e :)u0 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through thesec)3:ht) upl loop when the plane of the loop and the magnetic field vector are at an angle of $30^{\circ}$.

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58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional area of an adjustable single loop id y)4 zvm7 s )jdxwpplxftl/68b7c(z 8s reduced from $1.0 \; m^{2}$ to $0.50 \; m^{2}$ in 0.10
s. What is the average $emf$ that is induced in this coil if it is in a region where B = 2.0 T upward, and the coil's plane is perpendicular to B?

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59#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The flux through a coil changes okhy hro uadn+)m y l 6)6.0rd),6fosjfrom $4.0 \times 10^{-5} \; Wb$ 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 kfdqybdm+, igw1 fq,*uy1)pnv m .0w.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 average1b 0dvmm.nkw py)fyg ,qd i.+*w1fqu, 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 witrd r9i2z8t+ 6g rjya:q-(x qdjh 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 a111 a 5(aele )0mwc m9ofmm6 mktimzv4rea $0.20 \; m^{2}$ 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 ofc mp9b ;ac.jl2)lfds2 60 m flies horizontally at a location where the downward component of the Earth's ma9lbfc) s2p; jdc2m. lagnetic 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 consk d 0uhzbop-g/ lo521mrf4 ij/,+ttustant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while in , - i/dlptth/mu2+o5z10 bsu j4fgorka 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 generatp5)mqg74z2/ rkfgpuuor has 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 consists of 100 25a0ctq )w ha(v(vgogturns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 rectangular loops on its armature. Each loop is u:erwsq7 p;:t23m + whidmtun79zul512 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 perpendicular to the axis of rotation, what will be the maximum output voltanl t:; 2:qhri5mp+ uu e77wsdz3uwt9mge of this generator?

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68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns of wire of j1fu9u4 :kz.tg ;2 brgpo tla kq-j)b9area $0.090 \; m^{2}$ 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 Ahgex7:( lahw2.m0nyq C generator with an output of 12 V maximum when .e:(h27myanlqgw 0 hx 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 4 tz69 tcv5izix4b wio0, n8 l/lql+udgenerator 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 c*4 /56+ ukumg a sjt.fg1emmmf7kaa* $120 \; V$ 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 opdv4/xm3zptl /::ek kz,mmy y -erates on 120 V AC, and when runninyyt: kd,/z3vm/kpl: -xezmm4 g 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 W is9ie3 zdnvm7q* connected to a 24-V power supply. The operating current is 1 9nimq37v*zed.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 p1c0 m4*o ,3) sbfhyoflka hg w8c+/eqis connected to a 24-V power supply. The opye0 /wm134glc*o8 fb ,+)hfpqs oahkcerating current is 1.0 A at full speed. What is the back $emf$ when the motor is running at full speed?

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75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A DC motor of internal resistance 6.0 W is connected to a 24-V power supply. 6xq x)l wz0b:o The operating current is 1.0 A a)qw60 x lxbzo:t full speed. What is the back $emf$ when the motor is running at half speed?

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76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A step-down transformer is needed to reduce a primary voltage )wq02q9mv zmn 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 putuxjes;4n,c/q1 q .c7pt.je rimary of a transformer causes 14 A to flow in the secondary. How many turnu ccsj4eqtx .n/j1ep tq7;,u .s are in the secondary?

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78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, how many tuwaforh-4kb s 78/o3qbj 7)dm bpmeu/;l(zv4trns are necessary in a 110-V primary if the 24-V secondary has 100 r-)s8v b/hko z j4ump4fboltbqmw(3 e/ad7;7 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-turn sec2):o ofzm hb9yondary coil. If the current in the secondary i: 9f2o)hmbzyos 3.0 A, what is the current in the primary?

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80#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  5.0 A at 110 V flows in the primary of a transformer. Assuming 100% efficiek0l5 gntdic/ *ncy, how many amt l/n0*c g5dkips 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 7500 V at 10.0 mA. The *s ezs g ;)dcqqt3tuf y6-g:v(primary coil operates on 120 V. q*3)t- y(c;z sdefv:tg6gs quWhat does the primary draw?

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82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary coil and 300 turns on its secq.p0yemn df e d2kple8s2j9;/ ondary coil. If 120 V at 2.0 A is applied to the primary, what voltage is present in the secondar.9 psqkmdee e2/jnyl dp0 82f;y?

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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 prq(fp,lq wgt9oc y1a +;imary coil and 300 turns on its secondayl1; q9fca wgp(+,oqtry coil. If 120 V at 2.0 A is applied to the primary, what current is present in the secondary?

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84#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its second vku2ey8q-qb +2sw yz6ary has 200 turns. If the input current at the primary is 100 A, we can expect the output current at the8keq6 wy2zsq+vb- y u2 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 6mpd,uykc *)7: xp0 w0getejm turns and its secondary has 200 turns. If the input voltage to the primary is 100 jgw7 px0c,emk *m:d0tpu 6)ye V, we can expect the output voltage of the secondary to be

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86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer ;bsfg i5 h3t e).whtl1has 100 turns and its secondary has 200 turns. If the power input to the primary is 100 W, we can 5b;3gl1f eshwhtit).expect the power output of the secondary to be (neglecting frictional losses)

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87#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current at 120 V. The voltage is usually stepped lu).+vhrva6o mc)h o4f 86r mkup to 4500 V by a transformer and transmitted through a power line of total resistance 1.0 W. Find the number of turns in the secondary if the primar)) hhf46cmvou om.ra8l+v 6rky 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 s2d mb)r x4a3fitepped up to 4500 V by a transformer anxa42) ri fmdb3d transmitted through a power line of total resistance 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. T m1u1/wb1vwo: 9kpvv ehe voltage is usually stepped up to 4500 V by a tre1vmv 11kw 9/p bwvuo:ansformer and transmitted through a power line of 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 lit qr31ld :kje0ne 50 km long has a total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce eek3tj drl: q01nergy 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 resiswg d6l gmt(* 5eo3krcc: (tvj/tance 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 k gtwcc:6lme(rtv gj (do/*53 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 power wou uj e9jy3:u55(pvf( 2n eko-d9qwsywp ld be lost if t9uwpjv55-ow 2e:3yde (p ksjnq9(fuy he power were transmitted at 3000 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 ;f uh3j1lnb8)::yj a2 kodpx k440 V at 20 A. It is to be transmitted on a line with resistance of 0.60 W. To what voltage must the generator output 1k d) lk82jb:xjp yu3a :onh;fbe stepped up with a transformer if the power loss in transmission is not to exceed 0.010% of the original power?

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94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carries a current of 5.0 A. How m bgihpx+( ,e)n1iuh 1iuch energy is stored in the coil's magnetic fie)(hi 1 1+,ni ephguxibld?

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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 18-H inducuu -qv/bd43wftor. What is this uufdvb 3/-4qwcircuit's time constant?

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96#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the peak voltage in an AC circuit where the rms voltage is 120 v :( suegb9uv,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,y*htwj;ad0q-zpgqpe( 2) 0i c ubno- 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. 42cdhp/a1k w; c ,sstv What is the resistance of the lamp?/ p24htvsawc k c,sd1;

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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 connect)ak6 xm0a,s xe*1ubizy,kvny )*.sc xed to a 120-V ac power supply. What is the peak current through the resistoky0a.z) ex*ca munss, *ix x,vk6)b1yr?

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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 (vanbvwy l59mg+h yp4z; k,m(keuj.:120-V ac power supply. What is the power dissipa,5m p4+9ukv;lb. myz(gk:v ewnhaj y(ted 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 50-W resistq s319 o1pa/m m*ozwator 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 5ih ,dfegw gs-e fw13u ;g:y)n70-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 eowe dh/ggwi;d pz :w-f/* v,n)kh(v.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 inductor at ,9pf 9iu5gmpf 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 reacv*r* d3 oei3ryjgjp w: 7is:xl*bt(o: tance 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.a;e2ynqz 5i0k 0-mH coil have 14.0 W of inductive reactance?

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107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 157 W of inductive reactancev otkez84 jj95 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 l. sj1h(j) ;i *eepsbzV AC at a frequency of 20 kHz is applils *zsp(ei; 1 hejj.)bed 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 througv5kn4flqc5 09khez;*f) hrwsh a 2.50-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 capacitive reactance oy2 peq07t eebe d 4m9j1z5)ucvf 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 yau4hri5 p0 :rrfv)s: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 ;kx5sve :zi sj/q7.uw-mF capacitor have a reactance of 1200 W?

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113#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency will the capagz8(,cg1fcma4 d m.lwx- 2zfuts 8;zqcitive reactance of a 0.010-mF capacitor be 100 W1c;4xu(z.fzgdm2l88sq z, fwgtm -a c?

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114#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current through a 0.0010-mF capacitor at 1000 Hz and 5.003b nivqm;zb 6 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 ihdywy e tw:)9dgm2+3circuit with 12.0 W resistance, 15.0 W inductiv2iw3+m :etd9gy dy) whe reactance, and 10.0 W capacitive reactance?

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116#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the total impedance at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0 xr0jde,gvvlpys ;) i;654vkc-mF capacitor are connectev y rvl e;0 d)v,c5kg6j4pixs;d 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-W resistor, 20-m8m ohfs :2.ahi9x o*irH coil, and 1.0-mF capacitor are connected in seriesx 8:r*shi hfo2a.9oim ?

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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 serier7f8 uqlebidqg/ kp:tqi;5)wzz d71 +s with a 20-mH inductor, what is the impedance at 1000 tuib1k8;7ip w :q7 )d+ 5eqgzldzrf/qHz?

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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 seqp y 1,t/cb;in series with a 20-mH inductor, what is the phase angle at 1000ybs,1e;t/ cpq 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 se10wbk4c)om* vp es904voqmjd ries circuit with a 20-mH coil and 1.0-mF capacitor for a total impedance of 100 Ww odvmv440sc)o m0je91kb * qp 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 capacitancg 0cjo;yp;q;)e;rt5m;fv p iees is needed in series with a 100-W resistor and 15-mH coil to get a total impeda;pmgov;0;e;r qcypi5) ftej; nce 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 66i+ink1zzv ylmhkn:(6ww4y inductor at 5000 Hz for a tomi6knl nwz6v wy4 16i+k( yh:ztal 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 with a 100-kW resistor at 1.0-MHz )ut i9a2q4ien f2+qup for a total impedance of 1502 t)+nu fpu492iiq eqa 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 e(j-qq wjn9+qcapacitor. What is the impedance at 1000 Hqqjq9wn+ j( -ez?

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125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needeif/bd *da qn4-d in series with a 10-mF capacitor at 1.0 kHz for a total impedance /ai*nd d4b- qfof 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 kHzvvy(,uch (q*g33yn xx for a phase an (hv c33yy*vg(qnxxu ,gle 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 resistorq4v75 9kcr :xzipmrtd 2p-v1v at 1.0 kHz for a total impedance of 45vz 5vi p-4m 7pkxvqr:t2 c9dr1 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 i3z :3kndba 8jan series with a 100-mF capacitor at 120 Hz. What is the phase ang8z3dnk 3ja a:ble?

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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 100ijw,8w)3 xlbwx yf+(cg(zm3 m-W resistor, 20-mH coil, and 1.0-mF capacitizw8 y ,wxj()mw +xc lbmg(33for 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, and a jrwh. ,jpq qh1i/)zx7 m5 dfnrq//td4 0.350-H inducrxt7hp/ w) ddqqi4njj./z, /r5f h1mqtor. The 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 capacitozvi1hfc p qr.b9 c6-y*r of capacitive reactance 30 W, and an inductor of inductive reactance 30 W ar9qyizv pf-bcr*6 1.h ce connected 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 for a series RLC circuit containip(t361u mes kjng a 50-W resistor, a 10-mF capaciteks(6utpm 31jor, and a 0.45-H inductor, when connected to a 60-Hz power supply?

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133#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary in series wiay 0y ah)c..o xxto/lh2;1 oloth a 500-W resistor for a phase angle of a.x21x)ahcoyl 0h;t .o/ oloy $40^{\circ}$ 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 8c ,d.f4 ndkyb0u4x6 5rubvxy= 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transfe vk0.5bcb6,xr d x4nu4yfyu8drred 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, 15.+ iqn:zyzznni* dw7;)0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected zqz;n) *d n7n y:w+izito 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 8vl le7- hyr,:8ajg+ 4 z gtfdmv+pyt8$63^{\circ}$. 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 impedanc (od7yqrxjgtv + ft( a6j q1ou/5qh4 r./flh+ee of 60 W and a resistance of 30 W. What is the po x hjf /j(rh/q5o 7tg+t4ay+elqud.1r6v (qofwer 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 fa)b5dxd/)5 zfheeh xo exz *e3:ctor for a series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H indd efhzx5bxd) ) /o:ex*e5z3he uctor, 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 f:u)h euu5zi (jrequency of a 1.0-mF capacitor and a 15-mH coil in series?uiu(ejz5 h)u:

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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 sr 0y7a j-b)g +x;ofbbkeries with a 4.7-mF capacitor for a resonant frequrbb o)a f +g0k;xj7yb-ency of 10 kHz?

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141#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series wiu h4 g52yp598lhpqxe6 tbxtgbw )t ,ef:)sa +uth a 3.7-mH inductor for a resonant frequency o25u 5b6 fethglb x)+9au twpxeys,qht)48g:pf 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 mpj4pjllb3b h 7wj-r co 20/+lresistor and a 40-mH coil if the resonant frequency of the circui3wl7+b4rpo p- / l2bj cjjlmh0t is to be 1000 Hz?

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