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

 作者: physics   总分: 142分  得分: _____________

答题人: 游客未登录  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 unit-p ufd2sc ;k)jv72aths 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 induct58*qd 20rbf k+qnck dwion 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 lo ym9uoqhc9 a8x* e;jiqym,n(: ops of wire in a coil produces what kind of change on thqouiqn:cym8ha ( jx; 99y ,e*me 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 produces wu )j3eqevlg.,hat kind o,)3ueqjevgl . f change on the induced $emf$, assuming all other factors remain constant?

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5#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Doubling the diameter of a loop of wire produces what kind of change on the inde5 zlwq w5 4-ycwozxo5*nawjp,p )w9 6uc yo,5p49z wowj65-w) * wnecl qpaxwz5ed $emf$, 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 frb-s:yh4g sg5 nom 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 induced current in a conductor wi 19ygg73u drucll beu 3dg9c1gru y7 that which tends to produce which of the following effects?

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8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat on a horizontal table. A bar magnet is held above4;q+ro(e*j o j;isr k dxr4m:z its center with its north pole pointing down. The stationary magnet induces (when viewed from above)exjsok4qd:r*o ;+; rmz rij( 4

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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 7fnas-1 fw 3faw-qt9x flat on a horizontal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches9x1t-n w qfas-wa3f7f the coil, the falling magnet induces (when viewed from above)

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10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a table top in a region wjn*qfam p53b3;rvuo(mx 3 s)h here the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, whaa 3uopmms)qbf ;5r* 3(jn3xvh t 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 in a regio38u6yu,.dnznx w m0xl n where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above0 uu 6zwyx3,nlnd 8xm., 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 regi0o0aj1+rpt gron where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed from above, wha1 rr p0+got0jat 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 carries an ever-inv ajo+u9k7 0wqob5.gcv pu-5ocreasing current northward. Two coils of wire lie flat on the table, one on either side of the wire. When viv+c597p0oo5-qju v w b.kagouewed 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 wire with the north pole e8 bqv*)el+)oum0 vmvxntering first. As the north pole enters the wire, the induced e+*)vxqm mobu) 0vl8vcurrent 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 co m.2:b.fe o4xms.ix yni 3dv0snstant 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 omsb3xm4dxvs 2i.nfyei.0 .o: rientation 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 -ba x10czgt *qis rotated at 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 loop's axis of rotation xg*c-0 a1zb qtif 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. utzdx ; v wy*-up,6l3rot*k8m
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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 tef,ai. ;rk 4gpzk 4sz6hat 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 magnetnur;l wu 00l4kic 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 w1;f-dw+elp8p zpazo:p8: e w northward at constant velocity through a magnetic field that poi1dwpp po: ;e zpwz+ :8-lfwa8ents 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 angular veloci;jn +o yzv1n*2j *tpg+wo5qylty $\omega$ 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 tukwtc(y9v m bl+4y uxhkw(h +b:j .h,4ransforms

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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 req/gad 5ln : a:2r- x*w,8hikrwiebpl ,volutions each second. The frequency of the :rx* lnb/ir de,iqal8,apk5g 2:ww -h$emf$ 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 d2do6ipelpm r7)x+ g cjr3z9 +revice 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 dedzm)+gf )/ ycvvice 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 seyq:a0)il-;( r qws5ijv ebi5acondary coil contains more loops than the primary coil (lj0eaq -r iii:wba5 ;)v5qysthen 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 loop)zx/rkrj7p3w7l +y ap s than the secondary coil then it izpr xk /3w7+ar l)p7yjs 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 inpyspp yf12r xo-+5sk6y e e 71(ubx/kdaut

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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 resonan ;nfcbod-o9) mt circuit,

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31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected in series to an ideal battery of co xs 7ftjk:ed.k4ti7:c4ol; sknstant terminal voltage. At the moments ;4kes idlc7t k4:.:xtkfjo7 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 ideal1p6mr 93 fwf m 9fpe-yxe8w/ts battery of constant terminal voltf6m-wee 3mfr/9 9xs8pf 1ypwtage. 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 ani9ari2j7+gp9 .i tx gg8,mhsid resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the inductance is 2L. When it is connected to the same $emf$, what will be the final value of the current?

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34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductance L and resista1kphh e;z9 a1bnce 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 seriesj memk fr2,rea9:)( wq to a battery. The time constant for the circuit,mqmjaw)er r:9 k2f(e represents 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 h4y h gzzho.jgf-x9lvf-*,(rconnected in series to a battery. The battery is suddenly hf-lj,gz4.y9g(o vhf x*zh - rremoved from the circuit. The time constant for of the circuit represents the time required for the current to decrease to

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37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the same 40va, p1wpu ms q5j,flunits 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 circuit, the currentrn-v hlol(9-1 8oeoaz

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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 sunl5ng)7pd m;t pply. In this circuit, the current5nlnp)d; gm7t

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40#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The inductive reactan fzsbl7.2 rju+9f* xpgce in an ac circuit changes by what factor when the frequency is .g* sj7z+px frl2f9 butripled?

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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 voltag xmw5-dcw+wo1fx3s5g e across an inductor is doubled, the inductive reactance of that+o c1 55sx -dwxwf3gwm 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 them pj:5otob ,ds(f0mz: AC voltage across an inductor approaches zero, the inductive reactance of that (b t 5f,szd mp:o:mo0jcoil

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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 suw (o58 +rf0ovk7 msvwlpply. In this circuit, the curremk(7v frso+ 50ovww l8nt

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44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactang:i *oil-)p (rmql* 8dg tkvg:ce in an ac circuit changes by what factor when the frequency is tripled?8p dt*v-*m: l(glq) rg oi:kgi

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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 tzqb:) lj.ws z4he AC voltage across a capacitor approaches zero, the capacitive reactance )q bwls.zzj:4 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 inductor and capacitor(i mh)o pu(a97z-md wya;c f1r in a RLC semizm-dc9wp1a ou7(yrf;ha) ( ries 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 circ)7.(fog;zo i2dcw f vi(bvab2uit 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 impedar:hno0d+u xo: nce of the circuit increases if R increases.x+ n::r0 ooudh When is this statement 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 cirtr y9md p ,nw(8gs3f/tcuit 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 circuitw bnw9 v-/lx vckm59z; 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 douz4j dv5(fq a(xv+ ulx.ble in an LRC series circuit, the res54q a x +zlvxjvu(d(f.onant frequency of that circuit will

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52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that is driven by an AC ps,r6ofj1r00c t op tk/nc+.yp/. *sfp mzwl/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 circu9(w1g a) n(tk1-k -eks efphvuit 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 6jqaqqea6)dz33fi r)uniform magnetic field of 0.20 T. Find the magnetic flux through the loop w ) jfqr3z63ae)6ida qqhen the plane of the loop and the magnetic field vector are parallel.

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56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 0.10 m is rotating in a uniform86avazq).+rk k)b0 j okvdfo4 magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector are perpendic)qvrb 4zaokd )o+a0f6kv j8. kular.

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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 magnetic field of 0.20* rbp;,brherebs),,l/ g;l1bl;k g gt T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vectolb/rhg,*lbp r ;e)b gebr,lt,;kgs; 1r 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 (4gcym4 alt.p2p3 ms; (4shr fzi 1nrw ug-0icis 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 coi/ xv 5epd;1bsc bk7n/kl changes from $4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

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60#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil is wrapped with 200 turns of wire on a square frame with sides 18 cm. A dv0obofi5ps i4n 2l:- uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 Tlip n o2dbsio -:4f0v5 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 w8m orbvv1v+c r+m 9y)vith 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 an;z) c e(j3zt cp:p-oj6g7 fasrdh-;mid area $0.20 \; m^{2}$ is placed with its axis parallel to a magnetic field of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the negative x-direction in 2.0 s. If the resistance of the coil is 16 W, at what rate is power generated in the coil?

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63#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An airplane with a wing span of 60 mnii/-jeyp4,3rh)-ksx dx7q e flies horizontally at a location where the downward component o4y,iix eser hq)x3 7k/j -pd-nf 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 ( zylb2kih,z 9m0mks f8e(ye.angular velocity of 2.0 rad/s about89ilmhz.es 0yzy2ke b ((m, fk 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 loop jqg*/,iu1ewnlqfghy 3/f 7c(s 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 turns of wire of area 7;ugp caxr-6jr/ sf(t7 o. 6re57clnony*jcy $0.090 \; m^{2}$ 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/*iemcf/,y8n,7 d9 hzcg whdt its armature. Each loop is 12 cm long and 8 cm wide. The armaturf,niyd*wgc//te7z h,c m89h de 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 voltage of this generator?

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68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consis, l9c iaas2kn,z 3xao3ts of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced current.

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69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Suppose that you wish to construct a simple AC generator with an output ofl9hasjh /v+39nmj r/ro v 0fy8 12 V maximum when rotated at 60 Hz. A magnetic field of 0. m/0 v993 jh oyf8l/vr+rshnaj050 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 ma37 iu1a ,u*+8d)mvx trmc htoxximum $emf$ 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. Thep tqk va;l/-s9vphg6: 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 r8l ijeij)j75tpcq f6mfn*). 6.00 W. The motor operates on 120 V AC, and when running at full speed iiinm6t *q7)) ljj .jfcpf8 e5rt 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 intern96/ctod ta rimyb 6m)+al resistance 6.0 W is connected to a 24-V power supply. The operating current is dac 6y/mtbt +)moir 691.0 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 connectedc0txn1d*tl);ya-niyw ss8/ys s*i 1 i to a 24-V power supply. The*lynydi/tt*) s8ca-wx1 is n;i 1y s0s operating 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 4ckewqv9+ l l:24-V power supply. The operating cur :lc4l v9+eqkwrent is 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 totj,uy+sw6qpt8xu8bzo7 t8 k f4ar2 n 4u/b9zc 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 trq2gd+ cpr;c 0ransformer causes 14 A to flow in the secondarypcq;+rc2g0r d . How many turns 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 n,-rt st6f.p4i ul;abxl3 y;ujecessary in a 110-V primary if the 24-V secondi3t p sf lu;-;b,.yxj46atlurary has 100 turns?

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79#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An transformer consists of a 500-turn primary coil and a 2000-tur8b 8 v1mgnlpqg:vru;1n secondary coil. If the current in the secondary is 3.0 A, what is the curr vnv81lq1 :m gpbu;r8gent 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. Ajt+n07 9ats( sy2j w gbev8q4essuming 100% efficiency, how many amps at 24 V can jbe(e 02gqsj an+wv4st9t8 7y 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 s+vv)an)n0p;u gl n3kmA. The primary coil operates on 120 V. What does thennp)nv3 k )glvua0+; s 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 sj 0/ ggwb+, ld;bj :myscq0h)secondary coil. If 120 V at 2.0 A is applieddj00,l:; c)+hswgyg j s/qmbb to the primary, what voltage is present in the secondary?

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83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on its primary y8:a vw6 3mh6bx0knb0 hkw zd:coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the secondary :wn0 whkh83v06 bz bk:xya6dm?

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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 ang b/ nz.ka1um)d its secondary has 200 turns. If the input current at the primary is 100 A, we can emzk)n/g bau1.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 turns and its secondary has 2 ydo0x9 tb-v(u.qqp* w00 turns. If the input voltage to the primary is 100 V, we can expect the output voltage of-q0toqwb(vdu. yp*x9 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 itsly: 4s/ 7y7wbumsb j7z secondary has 200 turns. If the power input to the primary is 100 W, we can expect thu yzw4 7bsy 7:jl7/bmse 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. Thph cvrth98 v.j0a cj.3tx9ra 8,rfl1e l;hl3x e voltage is usually stepped up to 4500 V by a transformer and transmitted through a 0al91helt38 f.phrj9c,x v3hlj rv;. 8 axrct power line of total resistance 1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

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88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current j)j1z p ykp/w*4rni7qat 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resist7z4 inkj 1*q/ ppy)jrwance 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 is usual7 ucnrx(*0aa n pfot08ly 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 transmission line if the vol(0nxp*a fntru08ca o7tage 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 hava o3a w)p6tf)f7f/ris a total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up withiratv)p3 /7fa o )6ffw 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 :yfhi2 2mb f-- ggbd5ihas a total resistance of 0.60 W. A generator produces 100 V h2b 5g:2- gffmi-yb diat 70 A. In order to reduce energy loss due to heating of the transmission line, the voltage is stepped up with a transformer with a turns ratio of 100:1. What percentage of the original energy is 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 z:,wfw2c ;nuu-.vqovi fhe m3;qph (*ld be lost if the power were transmitted afhzwen-c. *3;vvu:ih m( ;, wfoquqp2 t 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 440 V at 20 A. It is to be transmitte m 1pxbh-j93zd3 htfe-d on a line with resistance e1mf xh3- jdtz9 -3hbpof 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 0.010% 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 / - h6ceb4y h1kc es3lnmorjc*jv d39-rv3 j)hcurrent of 5.0 A. How much energy is stored in the coil's magnetih*-m4 oyjeclv9j-3h/ecs36 rjk dh v3r1 cn)bc 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 1,r xx dprl5(4dz+kg )o kd*hf6.0-W resistor and an 18-H inductor. What is this circuit'lp5fk+h * rddg,)4doz1rxkx(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 Vzdu/1tsldpb 1 b 2h(i5?

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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 i 8 3yqe/ fhkmx9wwnd72: vik,w ld;v*g 9rz0mus 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 r *sctvv,8 yq1tesistance of the lam s1yv,qc t8t*vp?

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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. What is the e3id1wrmvn (7 .qj;hrle*g:7yphc 6c peak current through the resi 1w 7 hee r*p7m:3 jc;6dyicrvlg(.qhnstor?

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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 powe1zur z*(* f/epsgxdxra86 c7 yr dissipated in thea8fxz67z*p1xsre dr/g u y(*c 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 b3k(:iax vp7his $I = 0.80 \sin (240 t)$. 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 resistorq5b7 kx96z xfx)lsrw* 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 50dwi(jf zn2*zoo 8 l-+y-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 wm2 z:6hpd0hl ;6jjk9y,)bwsb9rhpuof a 1.0-mH inductor 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 reactance of a 2.z;g u (kqt;9d 6;zed8lenc5 hw50-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 14.0zz5 k lpby5o6*-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 ;vud3x+7 a (o)a4krd*rv)nnv odxbb1 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 inductor8)cno*ct5og+ dw :dg u when 120 V AC at a frequency of 20 kHz is applied to itucg:n85dt odg)c o+w *?

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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-mHonzgx,j z 4e4(+qu.czf/npi q ((o;em 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 reactan n4rj5wm-b-mvjw75 zcce of a 4.7-mF capacitor at 10 kHz?

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111#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What size capacitor is neededmhikfm :vj3f /,bb; ng62knf) 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-mgch u8i5jo) f/ ;4zbqqF 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 capacitive reactance of a 0.010-mF capacitor be wb*j4qvva(lc)sk/ b 3 100 W? b*aw(q4vv/ lkc)j b3s

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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 capacitoglz ag ,a 6g283 wugj+s3ufx)lr 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 resistancn*ch-,;m 4eh prgui 3oe, 15.0 W inductive reacta gnc *h3-u;rephoim4,nce, 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 15;j4 n95/+cpo+ qqr:t mjnvjs/prsh n500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor an+jrjhq5son c5mqr 4nt/v;+p:9 /p sjre connected in series?

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117#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle at 1500 Hz if a 100-W resistor, 20-mH coil,n og5 z3 4nk0xws+5rwc and 1.0-mF capacitor are connected ing 3k no+ rx05zc5w4nws 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 sepvrq6::dy5 q08 chjyzries with a 20-mH inductor, what is the impehq z8pq6jdv:y05ycr :dance 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 connected in sert08bh1 1ujlwd.ob +2gykvj0+r h6 stlies with a 20-mH inductor, what is the phase angle at0k 1lgbshd2++lj jtuby. 0v1rt6o8hw 1000 Hz?

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120#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in a series cirvc ovj *q *w:6co2l:xa .pib9qcuit with a 20-mH coil and 1.0-mF capacitor for a total impedance of 100 W at 1 2 96p*o.ivqacq:xbojl w* :vc500 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 in2+rf ndx:3k ts series with a 100-W resistor and 15-mH coik+3xrnfd t:2sl to get a total impedance of 110 W at 2000 Hz?

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122#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance must be put in series with a 450-mH inductor at 5000 k )0m3lvxc4juHz for a total imped3)v 0jm4xlcku ance 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 serien6ky ;,cg c t;kju)y t97hbsg9s with a 100-kW resistor at 1.0-MHz for a total impedance ofggh y t ks6c9yc;j)b7nutk ,9; 150 kW?

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124#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected in series with a 2wv.iz.k86q y0g.dy fw 9tbm:k0-mF capacitor. What is the impedance at 1000 H9 6.:mwyi0.bqkdt. fwg8 kyzvz?

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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 w(ydmzl- x1l i;9ir w3zith a 10-mF capacitor at 1.0 kHz for a total impedan3z-w(1 myxl9ilzdi; rce of 45 W?

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126#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with ahvtiuka)/e3 br66e :ss mr/7 z 10-mF capacitor at 1.0 kHz for a phase angle oakt7/b 6mu6he)izess: 3r/rvf $40^{\circ}$?

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127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is neede4334 l;vxzt vg 93fwv x v2;xdmgp1:rhuyw t,yd in series with a 30-W resistor at 1.0 kHz for a total imped2l,vpwrgvu4:dh y3x4ytvwfz ;t9x 3mvx;g1 3ance of 45 W?

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128#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is in series with a 100-mF capacitor at 120 Hz. W3odycd(a56f;hf- x- knj, as ohat is the phasec3 s-o;kfdj6,5o -fd(hnaxy a 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 a8+5ywv nr6/edrtrnf8b.ni zm 3;q4uk t 5.0 V and 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capa/rywnz bfneit6d5 ;vkr .r8n4q3m u+8citor 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 r(5h8ln wkx6 /ftp p :cajkn45resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuitl6kr /h (c pn58 5:jkfp4tnwxa 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 capacitor ox9io,ve yaa neaxg(x 5dx16f+ ss*k69 f 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 ssxe5 *n1xa+9ag,6vkyaxfo ed(9x6i 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 serie2qcnc1 45(v :+mr +jxdagiemws RLC circuit containing a 50-W resistor, a 10-mF c2md +mr vai5c gqn4e+1wj(xc:apacitor, 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 wi02-(-9iuov d*elmypzwgpomuu v7u * 2 th a 500-W resistor for a phase angle o mu70u-eupvyd9w*mu-i2l 2po * g(o vzf $40^{\circ}$ 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 ha0 .qqdmm(5 rhms R = 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the circuit be driven in order to have maximum power transferreqmr. m0(m 5dhqd 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 wfm3d*9 68 l ck6uol49wemwthxith 12.0 W resistance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circu* 8twl de 6ow6lx cmf43hu9km9it 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,d7gx (e wdjt)ab3 xy- AC 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 ,jw7h6y*s4 ccv vxrzo8/eil* resistance of 30 W. What is the icw/7zv o,x6lhcjy s4v8*er*power factor?

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138#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the power factor )7 gq99 nnpmavy cd+b/(w4pcd 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-Hz power supply+/a(9qpdp 4ygnmc7)9 bwc d nv?

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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 freq- j-s x rlfkcit52 /x4jit(zf9uency of a 1.0-mF capacitor and a 15-mH coil in series?2-ifrt4x/kx ljjis5z9 f t (c-

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140#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is needed in series with a 4.7-mF capacitor for a reso) +kq)3eha bdtmf84 vnnant frequency of 10 k+hdq)atenkf4bm)v3 8Hz?

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141#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a 3.7-mH inductor for vsp ps;8x(d/a a resonant frequency of s/xa8;p( vsdp 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 -ff7gm1gan 8,mv(vf ;ma bq6presistor and a 40-mH coil if the resonaga1gvm -nvff m7f( b6 ,m8;pqant frequency of the circuit is to be 1000 Hz?

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