题库网 (tiku.one)

 找回密码
 立即注册

 

      

上传图片附件

未使用图片

小贴士: 允许的图片文件格式为: gif, jpg, jpeg, png, webp,上传完成后会在上方生成预览,用鼠标连续双击缩略图,或拖动缩略图,该图片就被绑定至本题,显示在题目下方

本次作答已使用

小贴士: 此栏目显示的是当前作答使用的所有图片,绑定到某一题目的图片同时会显示在该题目下方; 删除使用的图片会将其转移到<未使用图片>类别


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

标记此题
1#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following are ugnfknv q n14*8 dycz66nits of magnetic flux except

参考答案:    

标记此题
2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Faraday's law of induction states that v- 1u4zewfawpz/3o+b the $emf$ induced in a loop of wire is proportional to

参考答案:    

标记此题
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 what kind of change on0jlb6yb .b zwhn,y+)kmjg, k8 th ym,gj z8j0w6kb.lbnybk +h,)e induced $emf$, assuming all other factors remain constant?

参考答案:    

标记此题
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 p9r wu695jmi blroduces what kind of change on the inducej99r5uwil bm6 d $emf$, assuming all other factors remain constant?

参考答案:    

标记此题
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 producec/8 yez6a :(n.nj( gvhwzcb7fs what kind of change on the inducegy6b z8fcje/hv.azn( n :(wc7d $emf$, assuming all other factors remain constant?

参考答案:    

标记此题
6#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As a coil is removed frbuzoj-/42rif om 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

参考答案:    

标记此题
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 8+-x gu +v/cjsscwgy*g;fz m.will be that which tends to produce which of f+ ;* gs+vm.x/8zgjcsg -ywu cthe following effects?

参考答案:    

标记此题
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 b6b7vo .+jlli*vxs:c w xf;c v.ar magnet is held above its center with its north pole pointing down. The stationary magnetl fcocji bv:xv;.+*v6s7 w xl. induces (when viewed from above)

参考答案:    

标记此题
9#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular coil lies flat ot qwmt p/qqg1;v4gy:sr r:5j*n a horizontal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approachwq4qtvsp;::r ytm5 1r/*j qgges the coil, the falling magnet induces (when viewed from above)

参考答案:    

标记此题
10#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a table to640 x5u,1n0bxv xmb.skz c jdxp in a region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense ofv0d scmux01j, . 6z4xbxbnk 5x the induced current in this coil as the field fades?

参考答案:    

标记此题
11#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a qm. tl2 (0oqwa.mv 3uxlevel table top in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed from above, what is the l.mq0(ovw ta.q3 2uxm direction of the induced current in this coil as the field increases?

参考答案:    

标记此题
12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil lies flat on a horizontal z8: 3ol19*k2ks.lkc;ejz r(otx-a y gnggm 7k table top in a region where the magnetic field points strai2eg *kngr97 xa1lcy-g 8zkokzt ; o.jlm( sk3:ght down. The magnetic field disappears suddenly. When viewed from above, what is the direction of the induced current in this coil as the field disappears?

参考答案:    

标记此题
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 c/kf9 ww ;gejj9arries 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 wg e/f;j9wk9j circles

参考答案:    

标记此题
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 entering fj do* he rpc).k,ec9r1irst. As the noro kj),1ccd.er *erhp9th pole enters the wire, the induced current will be (as viewed from above)

参考答案:    

标记此题
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.bi- 1-2fbhw/fj ni lwnstant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straigh2w-/.1 fbfihi w-jbn lt down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be zero?

参考答案:    

标记此题
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 s,usgs5jwr2 /t l0 hj4w;b/cqp(hn;kypeed 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 y 2u ,0/g hhw;jnt(c/slr5bqkp ;j4s wrotation if the induced $emf$ is to be a maximum?

参考答案:    

标记此题
17#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Faraday's law. tb)* 8)+ett bdmp*lfb
参考答案:    

标记此题
18#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
State Lenz's law.
参考答案:    

标记此题
19#
 
问答题 ( 1.0 分) 切至整卷模式 搜藏此题  
List the three ways thm:yjd8j.8eco z*q* ly 2r3f okat an $emf$ can be induced in a loop of wire.
参考答案:    

标记此题
20#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A wire moves across a maj5)c je8-k yj h*od1rzgnetic field. The $emf$ produced in the wire depends on

参考答案:    

标记此题
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 dghm.6jsp7,3 asjov2 u irection) is moved northward at constant velocity through a magnetgsvs p7,o6am 2j.uhj3ic field that points straight down. Make a statement concerning the potential induced across the rod.

参考答案:    

标记此题
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 v2u9 6bbfxc arfpqmul62iu7a1 ,1- wqqelocity $\omega$ 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

参考答案:    

标记此题
23#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An electric generator tr0y 0zp-,luwa lu7)m ocansforms

参考答案:    

标记此题
24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator coil rotates through 60 revolutions each second. The frequenc-2gkfsqkg 99 oy of the 9gk92fkqsg o -$emf$ is

参考答案:    

标记此题
25#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A transformer is a device usetip ts u,,5. p +0m-/j x3h0yhsieaamrd to

参考答案:    

标记此题
26#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A transformer is a device tha+gl0m ikw3.c2: szravt

参考答案:    

标记此题
27#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, if the secondary coil containsnlb/* 34qmmlesd0f ; p more loops than the primary coil thenmle/m43s nl 0*;pdqf b it is a

参考答案:    

标记此题
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 m0y,q.bu-jb6p0feyrawjj 2fp* ,*yh h ore loops than the secondary coil hhb pf,0*.e, yjy af0qjpwb2y -rj*6uthen it is a

参考答案:    

标记此题
29#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, the power inpeqbo7ktpu : ;lc7 a;g;ut

参考答案:    

标记此题
30#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a given LC resonaxtf,gnh .gterk +(206jzf 7 xpnt circuit,

参考答案:    

标记此题
31#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are conne ya)7x2yc pa l2bqk9q7cted in series to an ideal battery of constant terminq22l) 7by9capaqxky7al voltage. At the moment contact is made with the battery, the voltage across the resistor is

参考答案:    

标记此题
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 batte:lzbg 13g0 refq 6uua,ry of constant terminal voltage. At the moment contact is made with the battery, the voltage across the rb,ggle 130 :uqz6auf inductor is

参考答案:    

标记此题
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 connect7k ln482fgn jhed 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?

参考答案:    

标记此题
34#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RL circuit with inductaniv6683r3ee(e/ty 7m du fecpqce L and resistance R is connected to an $emf$. After a period of time, the current reaches a final value of 2.0 A. A second series circuit is identical except that the resistance is 2R. When it is connected to the same $emf$, what will be the final value of the current?

参考答案:    

标记此题
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 a battery. Th.glms nh)8qj z2jf6z*g/7czv e time constant for the circuit represents the time required for the current to*g.szj6fhjv cq) gzz m87/2 ln reach

参考答案:    

标记此题
36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistor and an inductor are connected iowz/e 6x -r+na7rb/yx b37euxn series to a battery. The battery is suddenly removed from the circub y6+3- oxw er ux/e7nb7r/xazit. The time constant for of the circuit represents the time required for the current to decrease to

参考答案:    

标记此题
37#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  All of the following have the same units exc ) atolfig2h*,ept:

参考答案:    

标记此题
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. qraj.)rwh) wxo+r7h +On this circuit, the current

参考答案:    

标记此题
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 curep0t5 oil6do 4ren4di05l ooe 6ptt

参考答案:    

标记此题
40#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The inductive reactance in an ac circuit changjki (x;y g+t-egzqef/ 15fc.ees by what factor when the frequency is triyf xz5qfj;1ei -e+g/.g kt( ecpled?

参考答案:    

标记此题
41#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the frequency of the AC v;b 71 ,r3r9bvi *m8k kglosnuwoltage across an inductor is doubled, the inductive reac rn7g,s m * wi13;ob9rv8ukklbtance of that inductor

参考答案:    

标记此题
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 approaches zero, the inah*exdb5d)8e c, jbd22 b/yifductive reactance of th2)5df bbjh8/bid,eca *2x eydat coil

参考答案:    

标记此题
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, 2y s.p2 evdn7 1qock;lthe current oes2kc 1y2.v7pql ;dn

参考答案:    

标记此题
44#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The capacitive reactance in an ac circuit changes by4c p)iytp-pn2vrc8 2c gtf1q6 what factor when the frequency is tripled2gn6pfqp4ry8c1 tic cv2 ) p-t?

参考答案:    

标记此题
45#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  As the frequency of theny5t 4; .72sgibgz-px-jbvn x AC voltage across a capacitor approaches zero, the capacitive reactance of that capacitonx z7p -bbn;it x-5.2gyvg4 sjr

参考答案:    

标记此题
46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase angle between to hu05w fj*rx:he voltages of the inductor and capacitor in a RLC u fho5jx0:w r*series circuit?

参考答案:    

标记此题
47#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The power factor of an RLC circuit is defint4ntwyu2 -svsaessi g .9h:08ed as $\cos M = R/Z$, but the phase angle can also be calculated from .

参考答案:    

标记此题
48#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit. Th5p l.6at3ks vse impedance of the circuit increases if R increases. When 3.sst k65vapl is this statement true?

参考答案:    

标记此题
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 cire1 (5b4-h 5d rwndxcancuit increases if $X_L$ increases. When is this statement true?

参考答案:    

标记此题
50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC series circuit. The6fsn/z2 ic a lq(na16g impedance of the circuit increases if $X_C$ increases. When is this statement true?

参考答案:    

标记此题
51#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the inductance and the caei-4hj+wz./r pc2cpeb)b 0anpacitance both double in an LRC series circuit, the resonant frequency ofb2 c r e.e+zja4p)0hn -bci/pw that circuit will

参考答案:    

标记此题
52#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Consider an RLC circuit that ib f;hze u/oy,(s driven by an AC applied voltage. At resonance,

参考答案:    

标记此题
53#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Resonance in a series RLC circuit occurs ati1. orf 8f0do e/w)dwhen

参考答案:    

标记此题
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?

参考答案:    

标记此题
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 l cg g9k,a9*qwae;0 zymagnetic field of 0.20 T. Find the magnetic flux through the loop when the plaw9g,e ylz qac;ga09k*ne of the loop and the magnetic field vector are parallel.

参考答案:    

标记此题
56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of radius 9ctna2 m*ed, d-3snt q0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop an,e-dtc n 29 *dqanstm3d the magnetic field vector are perpendicular.

参考答案:    

标记此题
57#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A circular loop of r g59 (iu5w1n8oiz2x vbcrzf0tadius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the maggo9vtn1 5rcz5xu bw28z(fi0 inetic field vector are at an angle of $30^{\circ}$.

参考答案:    

标记此题
58#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The cross-sectional area otdu ebifbjnzw ;1q,+ fh.50+ rf 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?

参考答案:    

标记此题
59#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The flux through a coil changes from*xoj,*t;pr, bppzy. q $4.0 \times 10^{-5} \; Wb$ to $5.0 \times 10^{-5} \; Wb$ in 0.10 s. What $emf$ is induced in this coil?

参考答案:    

标记此题
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 rl-36 u6v,s4l0xz5b;kxxrqrclypt4 square frame with sides 18 cm. A uniform magnetic field is applied perpendicultku;p46rz ,v-l x c xrl0r543bx yqsl6ar to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the average value of the induced $emf$.

参考答案:    

标记此题
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 w02,yirb +i3z,tngr e $0.40 \; m^{2}$ 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 $emf$?

参考答案:    

标记此题
62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A coil of 160 turns and areafgzu1-al p 7e46nmo9c $0.20 \; m^{2}$ 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?

参考答案:    

标记此题
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 horizo:dys d/+. p1khztu1 zentally at a location where the downware.k:dsd1z+1y p/th uz d 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.

参考答案:    

标记此题
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 a) v h cn*e1cnqbdnsi rk6.21 wm98ff0it a constant angular velocity of 2.0 rad/s about a vertical mn91vw )s k*0 dnff ii6enh.8c2crbq1axis 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?

参考答案:    

标记此题
65#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The coil of a generator has 50 looz+lb(a8l + rornv2f 5ops 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?

参考答案:    

标记此题
66#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of 100 turns ofun his0;kgv r:)c emyyfi+a gw/;6k7: 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 $emf$.

参考答案:    

标记此题
67#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator has 80 rectangularh4bk5w + es0c8 okayg3 loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loo 0b5+4h kgsw3 y8kcaeop 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?

参考答案:    

标记此题
68#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An AC generator consists of d8mb( sgepqd:1b8.3 u c)juww 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.

参考答案:    

标记此题
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 ofc3g;tqcz zw+7fl; r3w3i c*d y3g 3gxq 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of the rotatw tf;lgr3x3igcz;q w3dy37c* 3zq+cging coil is $100 \; cm^{2}$, how many turns are needed?

参考答案:    

标记此题
70#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  You are designing a generator with a m-pqkj2ip,r3x. kpb )pb n:abj t,fi /7aximum $emf$ 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?

参考答案:    

标记此题
71#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor have e;gtkc bmrn g 9i88w( ktyj710a resistance of 6.00 W. The motor operates on $120 \; V$ AC, and when running at full speed it generates a back $emf$ of 105 V. What is the starting current of the motor?

参考答案:    

标记此题
72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The windings of a DC motor h: rlw+.four 522x ik,3qv.4 wo;w:hhdateuc fave a resistance of 6.00 W. The motor operates on 1204fh.lrurw w: 5fav 2c,.3k ie hot+ wu:2qxd;o V AC, and when running at full speed it generates a back $emf$ of 105 V. What current does the motor draw when operating at full speed?

参考答案:    

标记此题
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 conso; .qwgzou 95nected to a 24-V power supply. The operating current is 1.0 A. What is the star og wosz95u.;qt-up current?

参考答案:    

标记此题
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 cokm;ztdd 8g+s4nnected to a 24-V power supply. The operatig+; 8sdzk4mdtng current is 1.0 A at full speed. What is the back $emf$ when the motor is running at full speed?

参考答案:    

标记此题
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 connejm,f-7 mj* ngbcted to a 24-V power supply. The operating current is 1.0 A at full speed. Wmngf7*-bm, j jhat is the back $emf$ when the motor is running at half speed?

参考答案:    

标记此题
76#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A step-down transformer is needed to ret0l q almz .8rmot168kduce a primary voltage of $120 \; V$ AC to $6.0 \; V$ AC. What turns ratio is required?

参考答案:    

标记此题
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 th5.vyt h. ,cdsye secondary. How many turns are in the seconda,ys.th dyc5 v.ry?

参考答案:    

标记此题
78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  In a transformer, how many turns are necessary in a 1t b k2 fpdp*-*(-ulnvd10-V primary if the 24-V secondary has 1 dvtbl(*fk*-ppd -2 nu00 turns?

参考答案:    

标记此题
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 2dcm,g9 tvut *kceqht8 e-, :u,ot(v:g 000-turn secondary coil. If the current in the secondary is 3.0k vh:ce(tg9 t,vg8do:c-mt *t ,euuq, A, what is the current in the primary?

参考答案:    

标记此题
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 10juk*3l ;f y2iv0% efficiency, how many amps at 24 V can flow in the secondaruy j*v;lfi k23y?

参考答案:    

标记此题
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 10vfp6odql8dc 44o(mf, .0 mA. The primary coil operates on 120 d846(cdqop lvm4f o,f V. What does the primary draw?

参考答案:    

标记此题
82#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60n lj7gh) d4c)n)(eyik 0cpsk , turns on its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, )y)cn dkg hj,lpi7k4ce(0sn ) what voltage is present in the secondary?

参考答案:    

标记此题
83#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  An ideal transformer has 60 turns on 30yy ,cnvk 3jofy1my3 its primary coil and 300 turns on its secondary coil. If 120 V at 2.0 A is appcy0y3yo fvj,3y1knm3 lied to the primary, what current is present in the secondary?

参考答案:    

标记此题
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 secondaryrujyu/j8en7, o6st3r has 200 turns. If the input current jur/tj63 yn,e7r sou8at the primary is 100 A, we can expect the output current at the secondary to be

参考答案:    

标记此题
85#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformer has 100 turns and its secondary has 200 turgsaw,b(l 2h une cc+12ns. If the input vn+l(gea 12,hc 2 cswbuoltage to the primary is 100 V, we can expect the output voltage of the secondary to be

参考答案:    

标记此题
86#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The primary of a transformepo asoo 8r3yx e3o 8w4sl/0z8urn r)j3m1yj 3yr has 100 turns and its secondary has 200 turns. If the power input to the primary is 1uo33nysjo8wrj0x)a zy3rmps8elo431o /8y r00 W, we can expect the power output of the secondary to be (neglecting frictional losses)

参考答案:    

标记此题
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. Th4m 200fwuckste voltage is usually stepped up to 4500 V by a transformer and tran4scwf u200mtk smitted through a power line of total resistance 1.0 W. Find the number of turns in the secondary if the primary has 200 turns.

参考答案:    

标记此题
88#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of current atu(ha - (d2jlfm0h5i+ntkeb - xx.zmv7 120 V. The voltage is usually stepped up to 4500 V by a transformer and transmitted through alb-di5+kef(j m0 h n uax(-.vhtmz72 x power line of total resistance 1.0 W. Find the percentage power lost in the transmission line.

参考答案:    

标记此题
89#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A generator produces 60 A of kqbo6bj,sq,q4v 7 .fp 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 percentage power lost in the transmission line if the vo vo sb6j,q7bq f4.kq,pltage is not stepped up.

参考答案:    

标记此题
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 resye)lf va,2i2psn*os4p ,jh) oistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due to heating of the transm )p*apih,o 2 ly)vj4n2,ssfe oission 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?

参考答案:    

标记此题
91#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A power transmission line 50 km long hasr-qv d7 -xz+e*fmpv0or 3yn)eael4 0v a total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy lossvrx)enmf3eev po dqzl- 0yv 0 r*4-7a+ 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?

参考答案:    

标记此题
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 cmi8w5wbq0dioc u2 78,:c,w qp;aweyV. How much less power would be lost if the power were trane7owp:8dq iwcu0aw,qym,c 5 2bi wc8;smitted at 3000 V instead of at 1000 V?

参考答案:    

标记此题
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 transf6t0b afr ac09mitted on a line with resistance of 0.60 W. To what voltage must the generator output be stepped up with a transformer if the power loss in transmission is not to ext 0 r6f9fba0caceed 0.010% of the original power?

参考答案:    

标记此题
94#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 4.0-mH coil carrie ezsng1pw7-1re ( rws5s a current of 5.0 A. How much energy is stored in the coil's magnetic field?r1es r 15p(sg7ze-nww

参考答案:    

标记此题
95#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A simple RL circuit contai tt fl1x z;e tj4vbe;,-5f2weqns a 6.0-W resistor and an 18-H inductor. What is this circue5 2e;vwztb1q ljxe; t-f,ft4 it's time constant?

参考答案:    

标记此题
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 t.;qnb cqxjl r. v3sl-oogr;48he rms voltage is 120 V?

参考答案:    

标记此题
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 ,sqy1n8 schsy*r/evn z:,+u u. What is the peak current?

参考答案:    

标记此题
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. Whato74c7 )*0zrj74icjb.uw0/d)ik itdwr zdfw t is the resistance of the lamrwc) 7do7u )djf t7iw.i0bzrczdt04 i/wk4* jp?

参考答案:    

标记此题
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. W s8 z2+j3w 4yyvtm*perhat is the peak curreey sj v4r*82wptm3 yz+nt through the resistor?

参考答案:    

标记此题
100#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connecteh q :5wr9zqv3ow4 6ruqd to a 120-V ac power supply. What is the power dissipated in the resistow4: 69zqv r5qwu3 oqhrr?

参考答案:    

标记此题
101#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistx fut(qrm (3a5,fjh v:or is $I = 0.80 \sin (240 t)$. What is the rms current?

参考答案:    

标记此题
102#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resistor i.-zx2 ablli+f.kr*+ pqf nie8s $I = 0.80 \sin (240 t)$. At what frequency does the current vary?

参考答案:    

标记此题
103#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The current through a 50-W resixc frt-m;34cdh2ebw 7stor is $I = 0.80 \sin (240 t)$. How much power on average is dissipated in the resistor?

参考答案:    

标记此题
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-m/hl .z)1pvtsbx,nvw 0H inductor at 60 Hz?

参考答案:    

标记此题
105#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the inductive reactance of a 2.50-mHjdwx2 io phb2)y*pg:f5xh;8 q coil at 1000 Hz?

参考答案:    

标记此题
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 1pq5 -() utt,k -1 vmzpi6iu4o.iayfmi4.0 W of inductive reactance?

参考答案:    

标记此题
107#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What inductance is necessary for 1 yj /e4r.:+dd bm3ku,;yxfl jb57 W of inductive reactance at 1000 Hz?

参考答案:    

标记此题
108#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What current flows in a 60-mH induct: mn.2c +8bx4knewqm.w dkug,or when 120 V AC at a frequency of 20 kHz is +kgewxn.bm c8w:,2.k 4ndu m qapplied to it?

参考答案:    

标记此题
109#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the current throug;1dswbil5c60f i .sysix u/kd4(f.t o h a 2.50-mH coil due to a 110-V, 60.0 Hz source?

参考答案:    

标记此题
110#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the capacitive reactance of a 4.7-mF capacitor at 10 k 7d.3 kyxono zj18)xnyHz?

参考答案:    

标记此题
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 readqq3qm )nt 3:( ks5s5l1cin ibctance at 10 kHz?

参考答案:    

标记此题
112#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  At what frequency does a 10-mF capacitj: hgoga:sor36p5,(z cnrf ;tor have a reactance of 1200 W?

参考答案:    

标记此题
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 100 lknufai-9 vbc 6c0+a: W?-c+cu0v6fa n kl9:a bi

参考答案:    

标记此题
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 H1 h :ztug9p,;hzzsxt2z and 5.0 V?

参考答案:    

标记此题
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 resista7oa24i gc y l:jcze886 .rxexynce, 15.0 W inductive reac:e7 zy elac2g.io4xcjrxy886tance, and 10.0 W capacitive reactance?

参考答案:    

标记此题
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,gb wq o.,4r1 k 3ylynpm2.fy5d and 1.0-mF capaciton mylbr fp.3dwq5y. 1,k 4yog2r are connected in series?

参考答案:    

标记此题
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:tdopvi) ze2r4 mno(.0-mF capacitor are connected in seri:pm(ztr e)n vo402idoes?

参考答案:    

标记此题
118#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If a 1000-W resistor is connected in series with a 20-mH innn3/ id la s2pw6s3h,sductor, what is the impedance at 1000 Hz?sp6dssn2h3 i /lna3 w,

参考答案:    

标记此题
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 t cnt2w:. zbug110ygw is the phase angle at 1000101tbwcyg:uw .zn2t g Hz?

参考答案:    

标记此题
120#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed ur -(r+wgudv* in a series circuit with a 20-mH coil and 1.0-mF capacitor for a total impu r-vg(wrd*u +edance of 100 W at 1500 Hz?

参考答案:    

标记此题
121#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Which of the following capacitances is needed3tb9ek zwb0*g4dxi4y in series with a 100-W resistor and 15-mH coil to get a tot443 bbd*0wxiyk9zt egal impedance of 110 W at 2000 Hz?

参考答案:    

标记此题
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 afl- *yxec)b s l9dl7qx u:m2)tt 5000 Hz for a total impey) 2xc:*l )se7xfdm9tb-q ulldance of 40000 W?

参考答案:    

标记此题
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 res6; ;c-ux-7rd4mx 3m vwbzcbflud9 ue7istor at 1.0-MHz for a tot9ccm-eub7d;vfd wxx- 3;ulzm u674rbal impedance of 150 kW?

参考答案:    

标记此题
124#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 10-W resistor is connected1q+,f ;-se 9ov8 xbwd gqqbj)m in series with a 20-mF capacitor. What is the impedance atdqj1g v fq;m sq-x+b)eb98 w,o 1000 Hz?

参考答案:    

标记此题
125#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What resistance is needed in series with a 10-mF capacitor at 1.0 kHz 10 pzpdkmwv c -8k,;vjfor a total impeda,zw vp0;8kck-mj p1vd nce of 45 W?

参考答案:    

标记此题
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-myi-ridd7sjj k0ud o 8,9og8m.F capacitor at 1.0 kHz for a phase angle 7doo8gyj .s8dji9 ikd, m0ur- of $40^{\circ}$?

参考答案:    

标记此题
127#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What capacitance is needed in series with a0r n ; xjft*krra;1f3b 30-W resistor at 1.0 kHz for a total im ja*k0 b;; frr3nrf1txpedance of 45 W?

参考答案:    

标记此题
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 capacitorgji 4: p2y utbfyo.8 -(+aipls at 120 Hz. What is the phasp-8:isy4 floyg+a2(i.t pbuje angle?

参考答案:    

标记此题
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 100ohug zu6l4 kokuyi5,7:t y)u l1s/1ou-W resistor, 20-mH coil, and 1.0-mF capacit u1uusk:iy1og k5oy 7,/ ltol)zu 46huor are connected in series?

参考答案:    

标记此题
130#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit consists of a 4x/op nh4trd ixtwxf-2- l6 t8n )/tut100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connet l284 -xt6nu xt/)o-xfhp/tniwr4dtcted to a 120-V, 60-Hz power supply. What is the rms current in the circuit?

参考答案:    

标记此题
131#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A resistance of 55 W, a capacitor of capacitive reactance 30 W, and an i elfr-w4kbex ) ,9j9elnductor of inductive e9f-ljrk, 9e4exw)lbreactance 30 W are connected in series to a 110-V, 60-Hz power source. What current flows in this circuit?

参考答案:    

标记此题
132#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the phase anglez4j oub/nh (508zvla3hje ;j u 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 supplya 0 8noj3 54h/jz(;u huvlbzej?

参考答案:    

标记此题
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 500-W resistor for a phpjq xtkxr7a3kj,vm+ ,,2k 3p mase angle of a3qkv+m,xj m23p p ,7 rtjxk,k$40^{\circ}$ at 10 kHz?

参考答案:    

标记此题
134#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A series RLC circuit has n/ellhs 958qrvwy a ,-R = 20.0 W, L = 200-mH, C = 10.0 mF. At what frequency should the ca- vl,q5shlyw /8e r9nircuit be driven in order to have maximum power transferred from the driving source?

参考答案:    

标记此题
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, 15.0 W 35rca s f2 z1uw,g.6l51uopkvsqq*zoinductive reac.*afcoq512uk1 o v3ls,uqzr wgp5sz6 tance, and 10.0 W capacitive reactance, when the circuit is connected to a 120-V power supply?

参考答案:    

标记此题
136#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The phase angle of an AC circuit icx m)08 bue.tgbt s+ bj;4zs4js $63^{\circ}$. What is the power factor?

参考答案:    

标记此题
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 30 k4h 5t. 4or8ni j7 m (a8db:plyrl+guuW. What is the powe l8narhr .4 lpmd4y8k:bg7u(ijo 5tu+r factor?

参考答案:    

标记此题
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-W2- )wev nkzqk9 resistor, a 10-mF capacitor, and a 0.45-H 9 kv-zq en)w2kinductor, when connected to a 60-Hz power supply?

参考答案:    

标记此题
139#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  What is the resonant frequency of a 1.0-mF capacitor and a 15-mH cof7 gxo qp99a t9rutr)p*mo52iu)yfd 7 il in series?x9um tp99ug5f* t)ap orq7firo2)7dy

参考答案:    

标记此题
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 res:x bsakw8*t*1uzl n6 lonant frequen k:l8wx*alnt b*zs1 6ucy of 10 kHz?

参考答案:    

标记此题
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 a resonant frequq q(iwuqs0,/k,n ob,zo q,ik,z,(qn u sw/b0qency of 1000 Hz?

参考答案:    

标记此题
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 resi*yur0,oli8jl stor and a 40-mH coil if the resona0,jllyi8u o r*nt frequency of the circuit is to be 1000 Hz?

参考答案:    

  • :
  • 总分:142分 及格:85.2分 时间:不限时
    未答题: 已答题:0 答错题:
    当前第 题,此次习题练习共有 142 道题
    本系统支持习题练习,作业与考试三大模式,作业考试自动评分,成绩排序一键导出,可设定动态变量同一试卷千人千题
    如果您对本系统感兴趣,想加入我们或者想进行任何形式的合作,请加微信 skysky1258

    浏览记录|使用帮助|手机版|切到手机版|题库网 (https://tiku.one)

    GMT+8, 2025-5-19 19:39 , Processed in 0.681162 second(s), 306 queries , Redis On.