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 unf- mcx9lcna,x jf+w 1ky+z-a3its 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 inducti (4w mix;fgh: -r1bswbon states that 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 f 6s+umb:72 hrqjyj:mkind of change on the mhmsqj +6:f72r bujy: 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 fid b,6aev.nt,6g g oy;hfk 7m6deld through a loop of wire produces what kind of change on the gaedf6;bko 6m .v7 g,dyth,6 ninduced $emf$, 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 produces what kind of change on the inyb,t4+w pfzfa:vw c r.3mcs(;ducrs4fw(,. z p+w;y atc:bfmv3c ed $emf$, 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 fr9xj j*dmm3y lzm :gw5w1 jd50jom 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 ofsa qphvl/1o;l - 1ds;r an induced current in a conductor will be that which tendsa-ld l1/p1vrq; s;osh to produce which 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 magnet is held a3i jwk)oo+6.h6l pekgbove its center with its north pole pointing down. Tlk +wkjo 36.heop)6i ghe stationary magnet 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 on a horizontal table.n:lagl 7sezd+ygu. ,0 sf54j 8ubr tu2 A bar magnet is held above its center with its north pole pointing down, and released. As it approaches the jlgurzgn.euftsa0 57:bs l8 y u +,d24coil, 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 ar .wtid*3z9cchuwxd1zt be+n h/ n13( table top in a region where the magnetic field vector points straight up. The magnetic field vanishes suddenly. When viewed from above, what is the sense of the in(w*3dzr9bt1t . xnh+hec/w1u z ic3dnduced 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 tabb+k 45 p5fuel1 chdhox s2/+smg:7izcle top in a region where the magnetic field vector points straight up. The magnetic field suddenlc5d2 lo7bsxup1z5 +fgs ik/me:h4hc+ y 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 horizontal table top in a 6(utv fu:kio) region where the magnetic field points straight down. The magn:o (6itu )vkufetic 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 carries an f /) ydux3pnujpy ),r4ever-increasing current northward. Two coils of wire lie flat on the table, one on either side of ) /djupyyp 3)n ,fxr4uthe 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 t/aaj)s; ) bbukhrough a loop of wire with the north pole entering first. As the b;)ba/ak) jsu north 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 constant angular speed about an axis whosw+hct b,sl) zds)9y;yfl5, dle direction can be varied. In a region where a uniflw;,+c)l z9l5f), h yd bdystsorm magnetic 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 i9x qn uc-e3 ss bq)a5xymnsc8g/; z85is rotated at constant angular speed about an axis whose direction can be varied. In a region where a uniform magnetic field points straight down, what must be the orientation of the loop's axis of rotn g9mq8 5 x3 ;a-cxeq5usbs/si)znc8 yation 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.8. a*b;k5agsm6oi yx q
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 . c1 : xuc;j0yjoi+gtm$emf$ 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 mat- l;r rxn x5:uaaf0e2gnetic 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 northwa(n x q)2ovnm1hrd at constant velocity through a mamnv2o1)q( hn xgnetic 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 angulndkvvyizz , af(y,zms: y-45;ar 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 generato oe1 nd)l9:m:qw7g6ety2 rqknr transforms

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 ezqkj31:f gk8ew; lp9lk ;++dd1vozx through 60 revolutions each second. The frequency of thp8d 3ld ejelw :zgzfk;o+11;kv 9kq+xe $emf$ 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 used tpl+fbvo * 1 y7fi;jnhu7u .m*no

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 deviceb8+brm1oj 4vn 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 secondary coil contains more loops than t:c/x5g5lrbb y/jq2 agv*e t)vhe primary coil c5vtb/5vl2*ag ) :er x/jbgqythen 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 containsmv*u(3g,a wqe( 2wji p more loops than the secondary coiw3pw(u(,qevj2 mgai*l then 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 in)8 v xdifa 7u fj2xg9dr.xsz,yy*e7r(put

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 circu l( +r.;ekfjjnit,

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 8cel )3.x znehare connected in series to an ideal battery of constant terminal voltage. At the moment contact is made with the battery, the nl8e 3h.zxc) evoltage 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 serkp1. 8tj oo9caies to an ideal battery of constant terminal voltage. At the moment contact is made with the batte.c 81ot a9okpjry, the 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 inductance L and resistance R is connecx6o u8 ybuy2el0 yue*tp r(3j:w:kvw 0ted 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 inductance L and resistance R is connected+2wj3h(fbc 4wvn8 i7ckr t:bq 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 indu5yshz z 0p(l.gctor are connected in series to a battery. The time constan p0(5lh ygzz.st for the circuit represents the time required for the current to 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 to a battv,9gajcmg b9k,f ipl6ga;0y 6ery. The battery is suddenly remove6l6jgmav9yp;, fb9ci g, a0 kgd from the circuit. 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 th rf0(atxc e2,i/sh ru3e 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 thixcq oi)0w wpf..r4y*3v2va ses 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 currerys u,1tk,mhi 7o1 jtyp6g9) jnyty7jh1 s)u6,mjg,1i 9po rtkt

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 circu/5icf p;ng 8)c1egx gpit changes by what factor when the frequency is tr gf /c1i8gecgnpp;5x) ipled?

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 inductinz +sepi hm8g jc52u: wl5-aaieap()4 ve reactance ou le:h) (pzj 42cw-5+5gaamsipi8e anf 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, thel s1(n cjbf,d5 inductive reactancef,bd (s5cnl1 j 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 connectepo i9p-mvf9q0jx eg956z1 ,ij dmgo h3d to an AC power supply. In this circuit, the currev6hejog -fpd zo9j3 i910,x9m5gp iqmnt

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 by what factor wk4le7 js5pb., pjass 4hen the frequency is trs7 5,e klbp.a4j4jps sipled?

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 acroc46hcrgcm e6zd hv./sba:2 3 rss a capacitor approaches zero, the capacitive reasgc6rh a .v4r/:dm32b ezc6h cctance 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 betwexo8 5/aol.se./jikbyen the voltages of the inductor and capacitor in a RLC seri/e8sl.o bo5./i xjakyes 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 yyyh*m4eh r/lv yu:7 5an 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 impedance of tmbs8i/xg8j2 s t fp g:-ikv -l(-ck.rihe circuit increases if R increases.gkj 8cp-srfi/stvi b:( 8k - g-ix.2ml When 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 th vrgo(6fw2lu5 e 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 )l;t9cb(9oj khunz,9y xxn; f )k9 genthe 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 an LRC series circuz9omm o kqvth38nc)*ktd,d 0)it, the resonamtotd8kv)qk 3h)nd*0 o 9zcm,nt frequency 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 that is drivq 4q4 f,4er7s -ivmden dfv77cen 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 RLC7q7fx xi.eb l8 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 radius 0.10 m is rotating in a uniform magnetiypb 48mm u qd;jh(+y(nc field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the mag my 4;h8mndjy(p(+ub qnetic 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 unim8mk +h bu ila9y(7p+ae kgn6-form magnetic field of 0.20 T. Find the magnetic flux through the loop when the plane of the loop and the magnetic fil79mu( -ghmaey+ k+kpn8 6aibeld 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 unid:;/t3vykd zy egcyk.c* (sv8 form magnetic field of 0.20 T. Find the magnetic flux through the loop when the planckdy( z: s3c/ygdyet8;vvk* .e 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 area of an adinu liq: )m-8sjustable 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 cha;*kpgrtu qg sck66 /.h91betynges 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 9w-lne-,s88dbllqm- cg pooo .gre46frame 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 s-e,l . wor geog -q8lco4nlm8- bpd69the 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 3.fna d zb w-rj3;d0nhand 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 area noiu9e31w o;ti da4 .x9juwhb1u,k,p $0.20 \; m^{2}$ 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 uqt mw(-h,n ky7pasrb31r0v. span of 60 m flies horizontally at a location where the downwar-vqknm a3071t .yrb s (p,uhwrd 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 at a constant angu ip3*8hytx+bl lar velocity of 2.0 rad/s about a vertical axis through one of its endshp3ib 8ly t+x* 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 loops and a cross-sq(.albe 8aq4 v h52fpfectional 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 10b- zz kctjj+;vt15ik n:i)0oh 0 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 .7 5rnj*v9ykwnm ucb9 80 rectangular 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 loop rotates in a uniform magnetic field of 0.30 T, which is perpendicular t.* bkj r5cyu7nm9 w9vno 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 consists5m 5kgyc8y gfa)v0 )ty of 100 turns of wire of area $0.090 \; m^{2}$ and total resistance 12 W. The loops rotate in a magnetic field of 0.50 T at a constant angular speed of 60 revolutions per second. Find the maximum induced current.

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 1/ ok ap)8gjjbwith an output of 12 V maxim8jpb1/ )aoj kgum when rotated at 60 Hz. A magnetic field of 0.050 T is available. If the area of the rotating coil is $100 \; cm^{2}$, how many turns are needed?

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 witr3wu: te.t ty4,kd wcz0v do52h 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 resista.zz0mi*o ip;c nce 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 have a resistance of 6.00 g:q/h n-wo8no: k(:vi ivu +anW. The motor operates on 120 V AC, and when running at full speed it geneqg(no8wk ai/h -o+vnv: ni::urates 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 cogu:* 1wrkmcz )nnected to a 24-V power supply. The operkcmr:*ugz1 w )ating current is 1.0 A. What 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.c2chx76 vr (54pm sljs0 W is connected to a 24-V power supply. The operating current is 1.0 Ajcs hcs mv65p(274xrl 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 con- byrqyco 0:qbuq,s86nected to a 24-V power supply. The operating current is 1.0 A at full speed. What is : yb8 6uy o-c0qrq,qsbthe 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 reduce a primary voltage ofuo8+g,9ct:f0,. ikphc mmm ud $120 \; V$ 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 ts ep3wzrf)m7s4w-3 ijo flow in the secondary. How m 3 sj-sww) pfr47emiz3any 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 necess0mre+g l9 3gy bg/xya(0;pdng8n, o qqary in a 110-V primary if the 24-V secondary has 100 turnsmyar3dp 9gbx (qgqno; y 80g0legn,+/?

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 5002 qs gtr3wo dp91wazx ro07,+k-turn primary coil and a 2000-turn secondary coil. If the current in k71s302dtqo9,rzowargwx+p 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% effici6 wg4dhuo0 f+ l8ntsn(ency, how many amps at 24 V can flow in ths0n u( lh6tn8 f4+gwdoe 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 providw9waw 2b)ho zm 6/80:ujtzeb80lmhz /cop-hc es 7500 V at 10.0 mA. The primary coil operates on 120 V. What does the primary bo-) 2 9e/w hzcmtzuhh:/ pmol jw68ca00 zbw8draw?

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 an u afiqu:l-;;cd 300 turns on its secondary coil. If 120 V at 2.0 A is applied to lu cq;au:if;-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 primary coil and 300nd5ve + 2z)o4byqbs +87n sudqisp;,o turns on its secondary coil. If 120 V at 2.0 A is applied to the primary, what current is present in the secondaru esvboisd78zb,)dq o n5 2qn4++spy;y?

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 secondary hasqc:p 04 lyf0n + i*gbdkm70xbn 200 turns. If the input current at the primary is 100 A, we can expect the outpnlcm0g0n x+* i4f:qd7 ybpk 0but 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 an;l( c;6mbadxu atk3d9fq(b* fv/a5jid its secondary has 200 turns. If the input voltage to the primary is 100 V, we can expect the ou; b j3da9( f(56umia bt ;afvxc/qkd*ltput 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 anduntu((6rhqb ,g3ge 859hwvz u its secondary has 200 turns. If the power input to the primary is 100 W, we can expect the power output of the secondary to be (neglecting frictional lossu(g3nu(btuq 9h hge8 wzr 6,v5es)

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 voltage is usuall3j7m+ c):n2c i7hq z ewphh76h c+njthy 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 zw7h73 j2c)hm7 jnh+ chq6ic:+pt ehnprimary 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.l8 m* +ndrjs:kn q.q 7n)yame is usually stepped up to 4500 V b7n rsdy.n)l n:a*m8m.jekq+q y a 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 k 0s b*i7 1m5hn) ivft9d(c e.kwmg4jqA of current at 120 V. The voltage is usually stepped up to 4500 V wqcvg.e( 7 *m9jtbm skni5)f i1h04kdby 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 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-d530cacsfrdc w1 r m+ long has a total resistance of 0.60 W. A generator produces 100 V at 70 A. In ord-sc fd10+w3 5rcdrc maer 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 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 hc-;k /+tidk.sk-hs i (owy.khas a total resistance of 0.60 W. A generator produces 100 V at 70 A. In order to reduce energy loss due th./ k(i whst.-y +so;kkd-ikco 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 V. How much less powetmf6hmpk 5a2* r would be lost if the power were transmitted at 3000 V instead of 5h 6aftmm*pk2at 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 bklxvu qrwl1+b q126s k5x,x8me transmitted on a line with resistance of 0.60 W. To what voltage must the gen l vk,kqxmuw+ r1s5qb8x 6x21lerator 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 current of p* .nsbucn tr ,a /5delzam9z*;n.)ri5.0 A. How much energy is stored in the coil's magnetic fp5ucnb;./znsld,i ratn *.* 9)mz aerield?

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 resig6c 3l2k is1i1qwhj2qstor and an 18-H inductor. What is this circuit's time constant? 2w q1qlihk c6sgij213

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 the rms voltage is 120 V?)ed fubvxj6 .j--lq+a am:0t4 pwpqzj.-f: ed

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. What i /(j nq2vn.sqzrzd1q.ke66 cos 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 qo5j,wj-g4po i;cl +bwd4 - mxinto a 120-V AC outlet. What is the resistance of the lamp? 4odqmgc+x4 w-jw p o5jib,;l-

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 1fh wn;qx*4zzilp7kefc a*/0 ,20-V ac power supply. What is the peak current through the repq7; *x fzcf,0/4winae lkz*h sistor?

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. Wha/ rk/r *4fbnbzt is the power dissipated in the resistob *z f/kr4bnr/r?

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 res nwtvg1.r(d1 :cm l,wnistor 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 cdtz;:7mm9vka+k q+( jq /vig50-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 507xi9biea;mzjr vw6/p q(( n+ t-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 iy33 iu4th(lq unductor 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 coil at 1000 yc; c3dtslg75Hz?

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 inductive reactance(k4bll g yc wxcy,77r(?

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 reactai bdl:xsv9q4w6m *ff 7nce 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 when11is/ joc ;xwz 120 V AC at a frequency of 20 kHz is applied t/jc;s wz1oi1x o 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 through a 2.50-mH coil due to a 110-V, 60.030dfi l(ukyl pz (:zat8/m3lc 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 re8g2 gv.ioe,e wactance of a 4.7-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 neea (-,vpalr l-zded to have 50 W of capacitive reactance 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 capacitor have a reactt/h ch(iix-t 7sp/)g zance 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 0bhcf g*j)zc :7v gc) vuph19mcapacitive reactance of a 0.010-mF capacitor be 100 Wu*gm)9 f v1ch ghpvz0c) jc7b:?

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 andnj2/v c6 zr rl;*beje/ 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 wdk* ;wos*(cu-etbm h1ith 12.0 W resistance, 15.0 W inductiske m u(*;c*wtd- h1bove reactance, 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 15.fkn 8miov8)fwt/o,l 00 Hz if a 100-W resistor, 20-mH coil, and 1.0-mF capatnimv f fwl,./8ok)8ocitor 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 resit40rfybj dkv pkk3.*, e:n8 gastor, 20-mH coil, and 1.0-mF capacitor are connected iga: y k4 .k3pkdrev*fj bn,08tn 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 (fmcvm x,1 wi;series with a 20-mH inductor, what is the impedancefvw x;,c(i 1mm 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 thetagp* bo 20q9g phase angle at 1000 Hzq*g g9o0pa b2t?

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 aa 5hwt*vnqd2w-k4 j4ux st)i6 20-mH coil and 1.0-mF capacitor for a total imped i)w4xwkusn-*t6j4t qda hv 52ance 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 c1ncqnq y0+e; oapacitances is needed in series with a 100-W resistor and 15-mH coil to get a totc+n0q1yn;e qoal 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 at 5000 Hz x uu) r*+v7tsdfor a total impedance of 4t+v 7dr*uxu)s0000 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-MHof-*ca 4 dcc0iz for a total impedc i0*- fc4codaance 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 connected in seried.ub7x(giw4ajq7 1 me iby)3 r5f7rpvs with a 20-mF capacitor. What is the impedance a7der)v fpgx3 7j(5w71amuy i4i rbbq.t 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 ch)z yl-g0x 2uct.t l)sapacitor at 1.0 kHz for a total impedance of l0yc)xlz h).t-ts 2u g45 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 ;+)vgyyj sd.1fs. zaf in series with a 10-mF capacitor at 1.0 kHz for a phase angle ofzs+ fs.j ;fag).y1yvd $40^{\circ}$?

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 cl;2(p,s5-olcucd ipfp86)u7ifn(dz1f h jd at 1.0 kHz for a total impedance oc5duh-2;ldcl6(pi,dfiu nc )fsfz p(7j18p 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 z umedu-,v8a-u5uvyl(r70q d -mF capacitor at 120 Hz. What is the phaseu-5vu ry8v0 zue,(u7-d q aldm 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 1yin87zpe ( -yn00-W resistor, 20-mH coil, and 1.0-mF capacitor are connec 7p-n8 iyy(enzted 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 consisen r*6:dl.w16o / mycy jae-thts of a 100-W resistor, a 10.0-mF capacitor, and a 0.350-H inductor. The circuit is connected to a 120-V, 60-Hz ptd/ 6r w1lmj 6 .ech*oyey:-naower 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 c(pcoyeyot km29ppi7;(;v l 9capacitor of capacitive reactance 30 W, and an inductor of inductive reactance 30 W are connected in series to a 110-V, 60-Hz power source. Whv29m eo yt; (p79k(ycc li;oppat 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 angle for a series RLC circuit6)y itpkm;2j e containing a 50-W resistor, a 10-mF capacitor, and a 0.45-H inductor, when connected to a 60-Hz powet)6 emik;j2yp r 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 necese u6x djib7 (0d8ta, bgq4yue;sary in series with a 500-W resistor for a phase angle of yxg ue(4 tueq7biabd;6,0j8d $40^{\circ}$ 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 whas ob,t(sh lbxan2 3(5qt frequency sh( n3bb2,h5atlqo( s xsould 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 resistan.pdu/o/trp f 06 qi5qww9s c+gce, 15.0 W inductive reactance, and 10.09wpo60r us+pdiqft.g c5w //q 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 d2; lv+i sutw*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 has an impedance of 60 W and a res zgt+h6 d0r.1mmi6o vsistance of 30 W. What is the power fav1m m0s +6igzh.ot6drctor?

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 fot4t(g yqk0 topv1pm v:-u).a ur a series RLC circuit containing a 50-W resistor, a q mk )1a-vpu t:v(p. uoytt0g410-mF capacitor, and a 0.45-H inductor, 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 anpc uw4s )-;hn 4n6rqpid a 15-mH coil in series?nqirw ;h4c p46s-)np u

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*5vq0ku(deokad4 kh0h3 i1kfonant frequencyihv*k fk0qd 1 5o0ahdkue( 34k 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-mizsc5wrs pj +- r38 /as6xfsk+H inductor for a resonant frequency of 10 ir8pskw zs5sjs-/6 +x+a3r fc00 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 4 /+ (3hy :dmabjnidwe50-mH coil if the resonant frequency of the circuit is to be 1000 Hme 3:bdw (nyhiaj+d/5 z?

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, 2025-7-8 14:38 , Processed in 0.926876 second(s), 305 queries , Redis On.