51fly国际课程 (51fly.win)

 找回密码
 立即注册

手机扫一扫,访问本页面

 

      

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: 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

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 units of magnetic flux excepx 5qi gaq:5o qwv04f8ft

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 thgs* ;9x 0)zt jlklj;ime $emf$ 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 produceqsfge7n./q g4kb2 o( hs what kind of change on thegsq .2/b g4kqon fh7(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 ofsp+b45d k +(0z pu jzngh(zyl( the magnetic field through a loop of wire produces what kind of change on the inn lj kz(0h sz+(pzgdb5yu4 p+(duced $emf$, 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 diametero ko g0/ ymc /z-3a faqx*.qzwtm4)4ay of a loop of wire produces what kind of change on the induczmkca40y wa qgf) 4 oo3m/xa-y/ q.z*ted $emf$, 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 from aj;h+x1 x)pi zgjd;mq/ 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+xkls) w,vyyj v);4 0aye0jyg an induced current in a conductor will be that which tends to produce which og+0,wkv j)jayvy x0ey)s ;l4yf the 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 bar mbp /6o)pyw.7x)dgqx sw-c65z pq; yzragnet is held above its center with its north pole pointing down. The stationary magnet induces -dzxx6pc;qow75 zwpb ) y.rqyp6 gs/) (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 w6xp1 ,f kj z:/o6tai pv;9xdxon a horizontal table. A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the coil, the falling magnet indu1 :6 xtx9/w pki6jp,fa;dvzo xces (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 top in a region where the magnetic +/( xr li2matijiul16x0a8cafield vector pointsa10m(+ r6 ix8iila/cx 2tjula 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?

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 aaqv2ivn/)i59+; efkea-bzk level table top in a region where the magnetic field vector points straight up. The magnetic field suddenly grows stronger. When viewed n+)fae; 9akvaziv 2e-/ b kq5ifrom above, what is the 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 table top in a region where the magnetimhg co;he5v 5sdf* g62c field points straight down. The magnetic field disappears suddenly. When viewed from above, whg c5d5v2sg6 ehmo;*fh at 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 goy 08sivfz0ka1cm a:,f3z+x horizontal table and carries an ever-increasing current northward. Two c mvikyxa0ao f1 3 g80:zfzc+s,oils of wire lie flat on the table, one on either side of the wire. When viewed from above, the induced current 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 wirezj4 f 1h * 8wp-nkbgl,d)wqw2r with the north pole entering first. As the north pole enters the wire, the induced current will be (as viewed,-dgh*wbwkw 4p rzn2j8fq 1)l 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 constant anwjv;++ +s,btta w4* :rndelvk z(yv +wgular speed about an axis whose direction can be varied. In a region where a uniform e+r s yv+t 4+wab(;lw+nkv :dvw*jt ,zmagnetic field points straight 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 speed about nw p 37jvcxb)+an axis whose direction can be varied. In a ren3 +jx7pvb )cwgion where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be a maximum?

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..te d1jaw24rp
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 that an ao (cc8s- x2qx$emf$ 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 magneticup4 ;6xnnpp2x 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 direction) is moved northward -.-ap thy 9pqbat constant velocity thro-9pyhbtp -q.a ugh a magnetic 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 angul/7i .g*6r2 i dkwfzyglar 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

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 trajj lvdefm6-.2 -)31drhuzbvmnsforms

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. Tbqod+5 .hn.tgnvwq 76 l3qi(rhe frequency of thnq q+b ld5h rn7q o.w(.3vi6tge $emf$ 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 u7pw;y* odrt0 used 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 ww:s1ma:y6 b 2b9m opqthat

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 doa1q-nwkbnl+b8 06.qwvop5:; xu k gcontains more loops than the primary coil then it 0lon1 q;6kd-kv.5bq gwpub 8 :n+xawois 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 more loops7 s* i 2kydduca3kw*-l than the secondary coil tcd7ask*u-yl3 k*i2 d when 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 power9xii+g;oyi.8r w 2pnr input

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 resonanv51hssmdeaz, th.: 0et 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 connected in series to an ideal battery o)i6 f3wbc*xs lf constant terminal voltage. At the moment contact is made with tsi6wb f*xc)3 lhe 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 iollz 02rz08q qn series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the2 zz0qo l0ql8r voltage across the 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 inductancehcamte fy/745 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 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 d hkq8r,0 qja;inductance 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. The time constuch,aq1qdk 19ant for the circuit represents the time required for the current to rqhak,cu11 9q deach

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 indk53cj /d pkrzv,n hio9lulz /,1;bf k,uctor are connected in series to a battery. The battery is suddenly removed from the circuit. The time constant for of the circuit re 5rbup /h 3n;ovl9zki/j1 ,l,zkc k,dfpresents 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 sa ;er-ru:wr l; bhj.54ejclhb 6me units except:

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. On this circuit, the curre r x4rqoph(n18nt

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 znwa bq, /5qm/9-vx piAC power supply. In this circuit, the currenapn,q 9 /qb5 vx/zi-wmt

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 x0 cwd:k+k/na in an ac circuit changes by what factor when the frequencywc dk:n/x a0k+ is tripled?

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 voltage across an inductor is doubled, the in mk)w nlo2mpt( 0pho47ductive reactanc(p k4mhwtnl7m) p 0o2oe 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 apprry z1t m8t/f )3nogdzx2wr-* moaches zero, the inductivrynmm8w t z*1r)x-f/oz2 d3 tge reactance of that 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 po gor,+tr2f9)5+(rk(hl bbbo ton7sumwer supply. In this circuit, the currentr5 +l7gtt bu)fo2s+nrobm( ,kob9h(r

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 reactac:t1h*rpfck .nce in an ac circuit changes by what factor when the frequency is tripledfpc*.h1ckt :r ?

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 the AC voltage across a capacitor apik*lvhx3l cxy)la8 l.p2e5 *uproaches zero, the capacipa*32ylu*xlil .e cv8)l 5 kxhtive reactance of that capacitor

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 the voltabzb5 6ebdi:( vges of the inductor and capacitor in a RLC series cirb :bibv5d(6z ecuit?

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 anl.h18s10bx h 6vitdc w RLC circuit is defined 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. The impeda8x6hvsg :o(dmf xedy 1 1fg/cg (*mzc9nce of the circuit increases if R increases. When is this state:e 86(v /*ycxdgmfcxm1do gh fsg9 1(zment 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 circzoa e*uf54qq8ac: n0kuit 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. The imps erflk8*(njt06rr 8n edance 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 capacitance both double in a7g -y7mgm* ep8a,njad n LRC series circuit, the resonant frequency of that circuit wi7yg ajp *8adnge-m,m7ll

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 i-/-ymv c+ku v2rdwfd7 4 lcj+js 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 whw3,q hvh)zet4m :.go( 4pf tiren

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 radiul((5-oz26 p6 jgspn kyq8pafs s 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the l6np2s ya(z-l p o5 g8qsf(pk6joop when the plane 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 0.10 m is rotating in a uniform magnetic field of 0.k.g7 f50 * mjr fxhkxvrl2v03e20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetil2.0* vgk xr hfx5m3rv07ej kfc 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 radius 0.10 m is rotating in a uniform magnetic field y2 / ;wh,j1juexxujz*i4uwm :; ewpe2 c+jo2 gof 0.20 T. wjymxxc pe22 jo w,eg*uiw4/; +;u1:uz2jje hFind the magnetic flux through the loop when the plane of the loop and the magnetic 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 asg*-2q vmc 6-l-5k y c:bdo asyc;ci/prea of an adjustable single loop is reduced from $1.0 \; m^{2}$ to $0.50 \; m^{2}$ in 0.10
s. What is the average $emf$ that is induced in this coil if it is in a region where B = 2.0 T upward, and the coil's plane is perpendicular to B?

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 c y6s3zld-5bzwe dl44 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?

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 square frame with sides 18 g38mn .twfe;g7y i o*bcm. A uniform magnetic field; wby.t*f7g emnig8 3o 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 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 withom+yy0 0ngs uo4 y.h7s 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 $emf$?

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 a5 7 f flomgr4vhq1g3d8rea $0.20 \; m^{2}$ 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 horizontally at a location w ocyy8nf c(2x5here the downward component5y82cfn(co xy 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 rl8i1u gkni 7g:otates at a constant angular velocity of 2.0 rad/s about a vertical axis through one of its ends while in ugni:1g7kli 8a 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 - at:7 vxc,jtk3f *7x9rsdzpvloops 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 cons,1: / 1qdgfdjx) iflcivux;h8ists of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced $emf$.

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 xkh99y ct6 xwu:x+,ho 80 rectangular loops on its armature. Each loop is 12 cm long and 8 cm wide. The armature rotat6:yk9uxxw9tx +c o h,hes 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?

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 1j)- *3s7q pietle5a/ 0vuvqln00 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 u ;uww: ,xow.jnh3au5 construct a simple AC generator with an output of 12 V maximum when rotated at whu :5wou;xa,nj w3u .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?

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 maxj3f5l4x hyvz (xc.o53 yir-o. rusb/nimum $emf$ 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 a resistance of 6.00 W. The motv og3jhlzg- / f /ub8f:z s;w66vkc:cior 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 have a resistance of 6.00 W. The mo y-7mj3cj*bl ltor operates on 120 V AC, and when running at full speed it generatesl3j-7l* jmcyb 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 resistancu x0d/xg 2,hkwuf,d7j e 6.0 W is connected to a 24-V power supply. The operating current is 1.0 A. What is the start-up current,0 jhx 2,/7ugfdxukdw?

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 lqx+pzx l 2oui0k*y4 /W is connected to a 24-V power supply. The operating cur4 +/p0zllq*2xoy ikuxrent 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 connected to a 24-V pypw*:q*wcz v* ower supply. The operating current is 1.0 A at full s:v c* z*qwp*ywpeed. What 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 *jjokg/,. szoto reduce 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 y9u/yrt-dumg3z+mqw5o l dm ;-dv/ 9a;6seew to flow in the secondary. How many turns are ;dvumrew9; yd-u z 6m el/m-g /w+ qay5odt39sin the secondary?

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-hy:kv/movu ;t.t f*3fafbk 1 in a 110-V primary if the 24-V secondary has 100 turk/ffyu-1a*f v3v ;:o.k ttmbhns?

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 c 9t3q8l2+ ekl3edcitpjl9;2 lauam ;roil and a 2000-turn secondary coil. If the currenielkjt32;r9m lalqt3e u ; 2d9a8plc+t in the secondary is 3.0 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 100% effi xoigkt,ak0f 232 g*exl9 v2niada6r5ciency, how many amps at 24 V can flow in the secondaroa l,in e*ri dt2fk32 k0v 2xaggx9a56y?

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 oe;qm 1*o)cmz )3wbw osf a neon sign transformer provides 7500 V at 10.0 mA. The primary co ew* qoo31;) mmz)wcsbil operates on 120 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 60 turns on its primary coil and 300 turycz)7 stm5/ dqns on its secondary cm )z7dcq/ y5tsoil. If 120 V at 2.0 A is applied to the primary, 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 h ;1ut7wv3dk hey: vjl2as 60 turns on its primary coil and 300 turns on its secondary coil. If 120 V1juhkwt2ev7;y3: ldv at 2.0 A is applied 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 1(p; vfyh+kfx;;m220ltl vaz n00 turns and its secondary has 200 turns. If the input cuy(20;tml;pf; l2vvn+faxzk hrrent at 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 secondack*-ap 7-:b 7 xf*zippbt p zgi:3n:wmry has 200 turns. If the input voltage to the p73zfi7b:inxgakcw pzp*m *: ptbp-: -rimary 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 transforme n lod04ka-83qhnc 0aoak *vb-r has 100 turns and its secondary has 200 turns. If the power input to the primary is 100 W, we can exp kkvn oaaa 03clh*80o-q-4bndect 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. The voltagb-.1el 6vau7 xzd7 kld5w/fbm e is usually stepped up 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 primary hasw7lb /ealbmv d-.zx175 fdku6 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 at 120 V. The voltage is usually a4qn5 d77sbq s2:y wvw9ukrx/stepped up to 4500 V by q:ak 74qdww 2n u/7v 9y5srbsxa transformer and transmitted through a 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 current at 120 V. The voltab,ifyn6 6n/; cuk rg2bhg z.i1ge is usually stepped up to 4500 V by a transformer and transmitted through a power line of total resista6g6ny 1gr,nhz;/b2c if ikb .unce 1.0 W. Find the percentage power lost in the transmission line if the voltage 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 relmi.o/ a1r ;5l( z fbxu,lqa0ysistance 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 with a turns ratio of 100:1. What percentage of the original energy would bl( .ifl zx1a l5yb;a0/uo, rqme 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 has a total resistance of 0.60 W. A gi io32: d-zmuqenerator 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 with a turns ratio of 100:1. What percentage of the original e3-: mq2iiuo zdnergy 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 V. Hojsm97 zvt a5(h; 1bglow much less power would be lost if the power were gl91a5v 7;bt jhz s(omtransmitted 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 tagto o.hxr 7 nvk()z(c(9ilr+ransmitted 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 v r7(r (cn(9o. z+i htxoak)lgtransmission is not to exceed 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 carries a current8cuw5u/aa9 prur h(w1 of 5.0 A. How much energy is stored in the coil's magnu (8a5hrr91wpu a/ uwcetic field?

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 contains a 6.0-W resistor and an 18 tv1cmghjml -ez,xh ,v14n )p.-H inductor. What is this circuit's time constant)l .-m vej zh v,gc,pntm411xh?

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 6m zuh/ipd q2;in an AC circuit where the 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. md6 mv9+jb.:g1udd 5vaeo kl7What 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. What is the p ou4bzatxyi+9 7rt(.-3 mro)ad7zfhresistance of the lau37o .b7ardzt a)x f9tm-rpih( 4oyz +mp?

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 a* z ijz+29s +rxah,fz+j gv2pwc power supply. What is the peak current through th j+pa h9xz*jr,w + f2vz2s+zgie 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 connected to a 120-V ac power supply. What is the power p.+m7(; go5yri.jvjxpz hn7xdissipated in the resistor5; xj7r(.x. v zpm+io7yhjngp?

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 resistor (+n6o8ojkb nt 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 -k pfj .ou q,db9 srmr+x;hoig-7q ++ja 50-W resistor is $I = 0.80 \sin (240 t)$. 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 g t9h6d9l3 jdw50-W resistor 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-mH inductor at 60 Hz * +2* 23suru*w jcczotdq6zfp?

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 2.5((vupl huc-tg6 ;e 7c1c a,mtf0-mH 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 14.0 W of induct zamr y605z0lnp sp4(gek3kmg 7)k+gz ive 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 157 W of inductive reactance r,6tfk1q he r(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 iw/gi6fzw-0ktr3 vfw; nductor when 120 V AC at a frequency of 20 kHz is applied to ifvgf ik/zww63- tw0;r t?

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 through a 2az t, 0d9f vqd5xq8*ms.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 4xchpknz jp /3 +r;;*v a6e1bay.7-mF capacitor at 10 kHz?

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 reactance at 1o o +x c0:xmslg1mq6*2imavq90 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 dob(tzv37, dsf kes a 10-mF capacitor 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 0.0(w5w( m1ypqpdhhd93. hxv +jl10-mF capacitor be 100 W+vh9lxhpy 53j (.qm1dd (hww p?

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 cpg*jc x uoox /y9;vi70apacitor at 1000 Hz 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 resistance, 15.0 W in-k rjl n2en/7rductive reactance, and 10.0 W ca-kr 2nr7 jn/lepacitive 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 resistoppn **0zb bx,ad,6dhgsdpr 5) r, 20-mH coil, and 1.0-mF capacitor adnsd b*6,ar, )px*pbpz05 hgd re 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-m)tg6j.jk z9 3deiaw n4F capacitor artnzdej4 .ja)g3ikw 9 6e connected in series?

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 bqu086a m7o+smh(j d mwith a 20-mH inductor, what is the i jbsmd7 omuhq8m6a( +0mpedance at 1000 Hz?

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-,aalg :vq 7 431o3dtjfyhfn4nmH inductor, what is the phase a,1thyvn7 nda 3 al:q4fjo3g4fngle at 1000 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 in a series circuit with a 20-74w qwft i4en;mH coil and 1.0-mF capacitor for a total impedance of w4f; 7ewnt iq4100 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 isjep q.)h3 6eds needed in series with a 100-W resistor and 15-d es6ph.e3 j)qmH coil to get a total 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 induct/chzdvbfb d , umyekj zudj4yd+q)g1o9.;(. 8or at 5000 Hz for a total impedz+/ g )yv 8.j yj; d9c,(bdu ofk1e.qdm4dubzhance 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 resistor at 1.0-MHz flngn8* ,dvrdw p t*b;)or a total impedance of 150 kWd,w)ndgl*b v np8r* t;?

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 connected in series with a 20-mF capacitor. What is the i 0 t;gnlyew-q d9(q-xym(ax6jmpedanq9l;da(- tn-yq6 g(j 0e mxxwyce at 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 k0nq6e qe1gs 2lHz for a total impedance nsq60g21elqe 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-mF capacitor at 1 irs3f37 pr 3g:fat 61c*yuorh.0 kHz for a phasra37 63trf go sh1pryfc:iu3* e angle 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 a 30-W resistor atut6e m q7;biv szs.7*ifz tl23 1.0 kHz for a total impedas7b;z lz quets3i *i m2tv76.fnce 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 w p*dyba-(rz7 jith a 100-mF capacitor at 120 Hz. What is the phase angle?(7z rdpy-b*aj

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 100-W resistor, 4m :mn 1 nuhlho5eox2420-mH coil, and 1.0-mF capacitor are chon41uh2 nlmm: ox54e onnected 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 consis2ymdkg-rs/ 7dzg 2mwjwh)z,9 8/szgqts of a 100-W resistor, a 10.0-mF capacitor, and a 0.350-H indu zjwyqrzm/ 2,d72 sh-wkmd9/gs)8gzgctor. The circuit is connected 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,vl 5f02g0rnl.4mh-oqwyx(b t and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz powg lw-qbth (xo4f mv2r ny50l.0er 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 anglexqti(p/klc 6 -8f5rr/3dtts gft vg)0 for a series RLC circuit containing a 50-W resistor, a 10-mF capacitor,(gr dptt3ks)8-5/ 0fl xctv g6qf/tri and a 0.45-H inductor, when connected to a 60-Hz power supply?

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 wit dy -b n+wm99phre;g+k w3k-e 3hm2yfoh a 500-W resistor for a phase angle of r-3bmgpe+y+ fhhwk9e- d92om;wnyk 3$40^{\circ}$ 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 R = 20.0 W, L = 200-mH, C = 10.0 mF. At wha hrzd h8,*pqhl+l+ . p)ofz9 ut4bt2ywt frequency should the circuit be driven in order to have maximum power transferred from the drivi2d, f4*hw)bhp tqzlrp l+89h+y.ztoung 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 resisary9tv(i(8oqoqnxcel7;p* 3ov 7 2cbtance, 15.0 W inductive reactance, and 10.0 W capacitive reactance, when the circuit is covl3 i7 c7eo;pvy9bq xo qr*n(8oc(2tannected 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 cir*mtj1(tb wuv gd4 1:pbcuit is $63^{\circ}$. 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 6 va,k/gw 9jz2)wkbn(n0 W and a resistance of 30 W. What is the,2z(k9n j a bnvk/)gww power 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 5fk gp0kx7fo 7knx((z20-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when co(kfox gxk pf 27(nz7k0nnected 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 co0wd8n r3ln; mmil in series?ln;rn8md0mw 3

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 resonan:tn.v2op 9- we*ddp :dns;t;o7cvlj zt frequencyv9zcowno*; edpl:t .2vsn d7 d;jt- p: 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 inducckdi5 jx*(dzz9 qvcbry o((2;vnhq * -tor for a resonant frequenczdvh*(;x5i v9 ycn((zbr2 okq*cqd j-y 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 resistor and a 404d *7 mhmjkdt7: 32gwu *4vzzzla1ehs-mH coil if the resonant frequencyuzjk 4 e 7hm2zgvw3lmhdt*:1ds *74az 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
本平台(https://autoconfig.51fly.win/)支持练习,作业与考试(自动评分)三种模式,群组成绩统计排序导出,题目动态变量实现同卷千人千题
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|手机版视频|手机版试卷|使用帮助|51fly国际课程 (https://51fly.win)

GMT+8, 2026-4-17 07:39 , Processed in 1.256451 second(s), 314 queries , Redis On.