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 units of magnetick8,a .ytaf2db9; uud z 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 th2jai py: gpla+lo-5yo 75luf:at 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 whtzr3nu )sai -gf5 jr71at kind of change on the r7ij-1n35au)ztgr sf 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 strengthk/kf5lkvdxu )r9c(f on1zx m9j/n76o of the magnetic field through a loop of wire produces what kind of changejc5 knkm1)9k vo9 /x l6df7 ozrufn/x( on the induced $emf$, 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 4-mozivy0 t d u;vp, m)(vhrl6of wire produces what kind of change on the induce0 um;miz-hd4(t v,pl )oy rvv6d $emf$, 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 a magn 0utk pz:vqy9:jgo46(0p az8 vxi9mfdetic 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 v:k4 wgi mb,qz, tl( .3gvc6gxdirection of an induced current in a conductor will be that which tends to produce mb6 gwz,xlgct 3 vv.i (,:k4gqwhich of 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+4zcb(v; ue xz magnet is held above its center with its north pole pointing down. The stationary magnet induces (wb x4e;z v(uc+zhen 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 on a horizontal table. A bar ei :-t7vywt.bmagnet is held above its center with its north pole pointing down, and released. As it approac-.tyw :ei7vtb hes 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 top in a region where the mag6(),h,ee: vkj c omzdm*-pj mnnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the inkn)ch pmj-e *dozvj :m6em(,, duced 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 level table top in a region whepqawvo9;oly/e s/qho-d /8)fre the magnetic field vector points strai l/qeoq /dhy-)8 /v9af;owpos ght up. The magnetic field suddenly grows stronger. When viewed from above, what is the direction of the induced current in this coil as the field increases?

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 hori prjs+3cc9-f.rhtkt74 e5pvxzontal table top in a region where the magnetic field points straight down. The magnetic field disappears suddenly. When viewed fro9 t rp+xf-3ct5j4phk7es v.crm 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 ascp; yz.yvqex (s*n7)nd carries an ever-increasing current northward. Two coil ceys.vs) xy*z;q(7pns 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 loopih8 fxmm*)sc lqo 0(0p of wire with the north pole entering first. As the north pole enters the wire, the induced 0fx(8lq*ic) hm sopm0current 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 constant angular speed about jjo27-qn (zjnan axis whose direction can be varied. In a region where a uniform magjjn-(qnzj2o7 netic 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 constane:guzu;s +m i2t angular speed about an axis whose directio:zui e us+;gm2n can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotation if the induced $emf$ is to be 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.hv 9.k0bibh g2 2th/vg
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 5 -(wbils1c1ga c/,dma,k 8vaggk xv9an $emf$ 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 magnetic * nnjt06(eijm 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) 6omdmo ) 4a4isoz+cpfpo:)+hk)v 8yris moved northward at constant velocity through a magnetic field that points straight down. Make a statement concerning the potential in)phkmdoos4v f+8: )aim)+ozy por 64cduced 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 rotat8nlg(k pz-gk2 slq06c+ja ux+ es at a constant angular velocity $\omega$ about a vertical axis through one of its ends while in a constant magnetic field B that is directed down. The $emf$ induced between the two ends of the bar is

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 y /ck2*lk/ qsv79klh qf(1 nactransforms

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 frtx 4e/j+ r9ejhequency of tx/t9j e4+ejhrhe $emf$ 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 us- g5 qdhqj32byul y0*jw.t9vlht+: yied 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 de0xia.+v1,qfx hx ro9 ve3 jz,avice that

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 secyzk,u- bni6 5 t zlg978qsgv1fondary coil contains more loops than the primary coil then 1zkut6b7g yiqlgf 5, n 9szv-8it 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 more loops than the secon- avi6 rlr,nkv-nfm66dary coil then it6,nv r 6i6na-lr-f mkv 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 jaf9i mo)s769ns is7 pinput

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 resonant circuit,tu d*xr4uy3fhcms;. 0du3 cx1

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 iyis2ta0 u55szh/q 4vzn series to an ideal battery of constant terminal voltage. At the moment contact is made with the zvq 245is/0h5tysa zubattery, 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 battery of constaz9vefqqd tl:kctd m / 7ts10:6nt terminal voltage. At the moment contact is made with the battery, the voltage across the inducto6:/st dm v9zftqtec0kq71ld:r 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 connected to anwqwhi (iykwhn z,t o 18s634)h $emf$. 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 inductance L and resistance R is conne q4:jsp:wo* zucted 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 seh4 bazj;/a ;reries to a battery. The time constant for the circuit represents the time required for the current ta ;rhj/a ;z4beo 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 in series ta*ypqi;vv rq)dmi)760t q-f y o a battery. The battery is suddenly removed from the circuit. The time constant for oity;a -d0 6rq7iq)q)vypmv f*f 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/n4r+;n. twkfm iouab e17c a: the same 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 thi4a7ge .b pgh,ls 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 curredm - u2e5 zhli85spqa(n2pq uslih a-8dz( m5e5t

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 ano.pv r4p :gn ,pu)wi0w ac circuit changes by what factor when the frequency ir4vpg )0u.: ponw w,ips 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 inow)5-j-tzi6 *g vdnvz ductive reactance o*n zzo5d)jv-wv-g6tif 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 approarv2z3lde(); oxj5 mhr.u w,l eches zero, the inductive re; j le(5mw r)h dreox2v3,.uzlactance 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 power supply. In this cirpodm. n)fwe xa +)tg/)cuit, the curre. metod gw+p)/x na))fnt

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 q+u9(zx cs8c dchanges by what factor when the frequency is tdscq uc8z+x9 (ripled?

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 approaches ze a5ooq4;bw7y)k h x(curo, the capacitive reactance of thatck4x7;5uh( obyw q oa) 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 v180typ 3pawpqoltages of the inductor and capacitor in a RLC series a8y10 tw pp3pqcircuit?

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 definerp- viw qb :(,a)ob:ucd 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 impedance of the circu+wep. 1a/xubdn1wrx ) zs/3hi it increases if R increases. When i.a /z) /x bph+1u1sn rdi3ewwxs 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 imped3dc(wdawu:h;d9 ;/m iz ten*dance of the circuit 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 impedance of the circuit increases if-g 9h cac;h3uf $X_C$ 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 an LRC series circuit, 4 8gf./q-pin9,pdf a d8btahd the resonant dh.p8d9 fb-pt f 8a4/qandi ,gfrequency of 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 (ynw5 x(9rfu 1 /szzonthat is 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 RL, ro fsxl,8re:C circuit occurs when

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 rad.nbk( no2i z v bzcn 0j7y1-9hwnm51mt jc9h5mius 0.10 m is rotating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the pla0 1nnzmyh c59jnj7 i.c(2bz51- wtho vb9kmmnne 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 mav)23kxp8 f9iipkp(y: npc8 f ognetic field of 0.20 T. Find the magnetic flux through th 2i9pppy3 ff8k(:vxk)8cpo ine loop when the plane of the loop and 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 radius 0.10 m is roozwxvls4 4 f.)iwp 0v0tating in a uniform magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic field vector wofv)lx44wis0 zvp0 .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 of an a3vnuzj6vi yz*ap, i/ ,djustable 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 chan*,gd4 mfvc)nb ges 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 25kzg2/a zy f.mv yatp7j,+d l:00 turns of wire on a square frame with sides 18 cm. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from 0.50 T to 0 in 8.0 s, find the average value of tf p,+j aal/7kyz .z:yvg2dt5mhe 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 w-*riy6q1) jl yru/ vh/wocz ;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 a8 hogslydmn t0t2aja 58v ;.f7rea $0.20 \; m^{2}$ 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 locat e4 veuu5nfj7*ion where the downward component of j e7nuve45uf*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 lounbv1uz().b g dv-od2ng rotates at a constant angular velocity of 2.0 rad/s about a vertica(udg-bod2.bv 1 unz) vl 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?

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 hz;cjhozh wbbtr;o .z (-1 q,b1as 50 loops and a cross-sectional area of $0.25 \; m^{2}$. What is the maximum $emf$ generated by this generator if it is spinning with an angular velocity of 4.0 rad/s in a 2.0 T magnetic field?

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 1* oqhkr 8w,7fy00 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 80 rectangular loops on its armature. Each loop is tl bh :edv72y(. ulie812 cm lo hli.:e(udt bvly82e 7ng and 8 cm wide. The armature rotates at 1200 rpm about an axis parallel to the long side. If the loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular to the axis of rotation, what will be the maximum output 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 100 turns of wire of are)gwa4x ,;hyse,e c td8a $0.090 \; m^{2}$ 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 o*1f o*,hj focgenerator with an output of 12 V maximum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of fcjho,* fo1o*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 gener/sm5w24nkv.a ock 8c8snkz/ aator with a maximum $emf$ of 8.0 V. If the generator coil has 200 turns and a cross-sectional area of $0.030 \; m^{2}$, what would be the frequency of the generator in a magnetic field of 0.030 T?

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 motor*nq z;tjcm: .o 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 motor operates 3hhcq r/ pj1o kr249ifdj ,/pzon 120 V AC, and when running at full speed jqfh3p2khr/dcz41j9,p ri o / 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 connected; 1 -(k-oiud iijbgd-d to a 24-V power supply. The operating current is 1.0 A. Whau -dbg;joi 1kd(di i--t is the start-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 ib0 klg;:4sh u.fnu -ozs connected to a 24-V power supply. The operating current is sl:ohu.bf g;-kznu40 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 sbclfwc. i-6lh*;n6f on*u5/zdh7tois connected to a 24-V power supply. The operating current is 1.0 A at full 65wiohslho ldfcnc z f* ;tu7/-*bn.6speed. 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 to rmwu *mmy l1glnhct 444spq;( *educe 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 the secohk1n 8//zq zxx ir+,xondnrq+/,hxo8xi kx1zz/ ary. How many turns are in 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 in a 110-V primary if the 24-Vp 4bq- usc7:jo seconda 7ujqso-c:b p4ry has 100 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 coieh)yj rm: hqn: 3pw1,afe:c h2l and a 2000-turn secondary coil. If the current in the n:,: 2eha )qwf3my1hr h:jcepsecondary 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 trand86 d;(mp . epcj;eaknsformer. Assuming 100% efficiency, how many amps at 24 V canmjcpd (akeen.d;68p ; flow in the secondary?

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 10.0 mA. l gi2*li u79kcw6 i;rdThe primary c9kc7i*gwli;2ui 6 ldroil 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 tuahk6d-q re7+nrns on its primary coil and 300 turns on its secondary coil. -n7h6 qea+drk 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 has 60 turns on its primarytq z cr(.7fi7q 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 thet. ci7qqrf( z7 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 secoy etw5oka6mi.3p,kp pf+o 24 dndary has 200 turns. If the input current at the primary is 100 A, we can expect the output current o4y.p2k3i ,ow6pa5mf ket+pd 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 qlz9z*5 w8 dyu/fgx ;vlz3r y.gr x1:uand its secondary has 200 turns. If the input voltage to the primary is 100 V, we can ef/8wz9l ul5r1z:r xzd qyvg.uy;g3 x*xpect 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 transformer has 100 turns and its secondary has+* pez5y qq/ubw. (acm pmdc(7 200 turns. If the power input to the primary is 100 W, we can expect the power out(+c.wppze*cd5( myb mqa7 qu/put 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 voyn9(*x8p vi fpqrz4 2mltage is usually stepped up to 4500 V by a transformer and transmit *z2(xy qr4fi89nvmpp ted 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 at 120 V. The voltage is usually steppfunf;7x +v y c32sjt*a4v*o jued 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 transmiu j;vcfv74* n2 ujx+ as3foy*tssion 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 *es;/;;xholm3 lt mueV. 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 voesoh;m3/xmul l ;*;te ltage 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 ;so5up(zi es1line 50 km long has 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 with a transformer with a turns ratio of 100:1. What 5;pe zsio (u1spercentage 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 has a total resistance of 0.60 Ww: 2a2rys6yngy 1bzxwh 99tk1 . 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 percentag w6291a hnxzs2r1:tyk y9 wgbye 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 aq9 rmmg+9t f(muq3: wut 1000 V. How much less power would be lost if the power were transmitted at 3000 V instead :q q(w99m rf3 +tmuugmof 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. I jkg 9rff4qm+ ):,qldkt is to be transmitted on a line with rr:,qmf gk f) 9+qjk4dlesistance 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 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 curre va*o5oxd.z 7snt of 5.0 A. How much energy is stored in the coil's magnetic fieldodv a 7*zo.xs5?

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-H inductor.nqzq/2bzg6* i What is this circz bqn2 6qg*/izuit'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 bxw- tojn5urw-3zs;cxgj+ 7 .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 ) z5 dap0asz0zi(f7 jo120-V AC outlet. 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. Wha(f- bal3c639r4 qfmgtenvc vv1w8 4ukt is the resistance of the la-l8 64etfc ca g3(v3mfrkqn14vu bw9vmp?

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 fd/jnm)8hm1v power supply. What is the peak current through the res )8nvj1 mhfmd/istor?

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 ioi9pmnh;7 vb n8 ;l5ia 120-V ac power supply. What is the power dissipated in the resbnl ;p9i i7o85ih;nvmistor?

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 1 wsvgu*x n k .t k98ppslz34uky,p-6cis $I = 0.80 \sin (240 t)$. 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 ar irpcj98f3gz,(vd: d 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 50-W res g)ek2r1n ;ffmo17nmk eflf5+istor 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 1.0lsxb1n+d6 a4wvesjp yy/- a5)-mH 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-mH cgb- 0eg/oa+t roil 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 inductivgej8ga vqr+0: e 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 rseffhp7 .vo cgg6cl nf(*h:o t,45a9of 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 inductor when 120 V AC at a 7 7/jwgmvsf g2frequency of 20 kHz is applied to it?g2 w7mjvsf/g7

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 2.50-mH coil due to a 110-V, 60.0lwwl)gb6u xe / 131oezpb;q b( 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 capacitijqljga0i l4g/-7;7m lohd7 j or 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 1cd rjmcs *.*)1mo nm6u0 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 capacitor have a reactance of 1200w/6ivke0: alweh x;i:p.(fkp 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 tobktv,lkf/dwj4):n *he capacitive reactance of a 0.010-mF capacitor be 100 Wl/ fk vo4 d,:*tnbwjk)?

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 Hz an(tjs6,41ag w jt pi0d1xqe05hunt rh8u- ru y5d 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 resa( - fjdt,4mvelfy v;+lw1hnl.hi0o5istance, 15.0 W inductive reactance, and 10.0 W capacmve;w0lyhd1 f+vh ll (n-.a i5 ot,jf4itive 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 impedantnvrw*6zz8z5w .l: oace at 1500 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connected.zz8nr5w w*a o: tzvl6 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 if3nsb ibt 5znv7.rw:x/ a 100-W resistor, 20-mH coil, and 1.0-mF capacitor are connecb5tn7zv 3is.xr/wn b:ted 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 whg,wnq a l5q 1.ozw36hith a 20-mH inductor, what is the impedancw.o6w q1 nh,qhl3ag5ze 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-mH inductor, what is thas,wc1p;to bl2 jv,i7e phase angle at c7tjo,b; il1,w p 2sav1000 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-mH coil and 1.0-mF capa gv;ydcbid)(swega8h/mq159 h* p 8kocitor for a total impedance of 100 W at 150098w*qg 8ghmvb(id cd/ e ;sky5h1 o)pa 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 needed in series with a 100-W rhuv.fy 3ci x0q .7yoaa(6/zr mesistor and 15-mH coil to get a total impedance of 11c f0h uvz./a6(iaorq 7.xym3y0 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 withz 34h2gvltupp* n5ki/ a 450-mH inductor at 5000 Hz for a total impedguzpk p*h t2v i5/l43nance 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 serie)yp co7ob0 kf0 i*,suus with a 100-kW resistor at 1.0-MHz for a total impedance c7i s*pfyko0ubo u,)0of 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 connected it3u.rulio,7g 2sy dk *n series with a 20-mF capacitor. What is the impedance at 100dgyr.7ls,3t 2i o*u uk0 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 2s.pz,*lu v- w1jgczqin series with a 10-mF capacitor at 1.0 kHz for a total imped.vqu *ps-g2 w zzl1cj,ance 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 wi9)sqx0 md no(v(a * zh:fgjem0so be/.th a 10-mF capacitor at 1.0 kHz for a phase angl(:)q/b d (ea xgnss9zmmhv*.0o e0 ofje 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 resischn/f /oapl2*tor at 1.0 kHz for a total impeda/ c2 hln/ap*ofnce 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 wivjsgy t5 2cjy*b1)4 p exl3i*eth a 100-mF capacitor at 120 Hz. What is the phasesyi j4*c)g 32lv pebjyx5t 1*e 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 100-W resistor, 20-mH coil, anj3qlbl9m10mg (/wk dc d 1.0-mF capacitor are connected in sq0gd/cj w 1m(bl3 9mkleries?

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 100-W resistor, a 10.0-mF capacitor, a8py46anf gqzf /mn f+4nd a 0.350-H inductor. The circuit is connected to a 120-V, znn8/ f4fmp 4qg a6+yf60-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 capacitivekr 34 -8 vdzvr9/5zwu etmqy0rk,z(g h 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 fd ,h3(t z/kuke 49vvyzrr0-q gzr85mwlows 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 angle for yzu 3 khts659oh30.tw+mjlxfa series RLC circuit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inm xttw+lz 6h5j0 sy o.3khf3u9ductor, 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 with a 500-W resistor for a phase anycmz. aj dp-08gle oyjc0 .-d8pazmf $40^{\circ}$ 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 what fukch9 v + 5* 6d67emf0f4 p)cnpgpnepmrequency s57*6 empm 6ved knnpp+cgffc49 up)0 hhould the circuit 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 ugp5pgz2;k pe27tpy.W inductive reactance, and 10.0 W capacitive reactance, when the circuit is connected ty z;2up5kgep pgt72p.o 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 yy:)0n anic64ec nx)n AC circuit 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 ha3( btajd:mr k4s an impedance of 60 W and a resistance of 30 W. What is the powejr4 b:3tmd(ak 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 circu+ 22zlgch xxmu-6kj3dit containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when - gz mh +l6xcuj22x3kdconnected 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 capaz6 a6oreoy9v6citor and a 15-mH coil in series?v6ozy6 eo96ra

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 capacitooa(lb7 yq9hvi,j4uk5 r for a resonant frequency of 10 v aj4 ubkqi79(,5yolhkHz?

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 inductorez0 v, e2b2qw0: bpz)xcciuv) for a resonant frequeq2cc wi b e0pv):2) exbv0zzu,ncy 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 resistore q* :jl.p)kyn and a 40-mH coil if the resonaj peqkn.l)*y: 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|手机版首页|使用帮助|题库网 (https://tiku.one)

    GMT+8, 2025-7-15 05:06 , Processed in 0.958852 second(s), 305 queries , Redis On.