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 Unit18: Electric Currents
本习题练习试卷来源于51fly国际课程 (https://51fly.win)， 为试卷打印版，您也可以在网站平台(https://mail.51fly.win/)直接 访问本试卷的在线电子版并查看正确答案与解析，搜藏保存任意题目到收藏集。 访问方法: 平台首页左上角"通过试卷号快速访问"输入试卷号 76，并点击直达试卷；或浏览器地址栏内直接输入本试卷链接 https://mail.51fly.win/test76.html  教师使用本平台可以抽题组卷或一键复制他人试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力。
 作者: physics  发布日期: 2022-08-17 11:19    总分: 80分  得分: _____________

答题人: 游客未登录  开始时间: 22年08月17日 11:19  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  
  A device that produces electricity by transforming chem5c9cvc7yr yyme+3qtb cx6)5 : .lsnjgical energy into electric jvcycy3e65+9cmbx57 n)st :crqgl.yal energy is called a

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  
  A car battery

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  
  The total amount of charge that passes throughifejokyqe3)vr) a: (ricq tf 2)2.k ov4-p+z b a wire's full cross section at any point per unit ofrye 4f )ikoa.2ef:q z r3iqvbp)oc2+j(tvk-) time is referred to as

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  
  The direction of convention current is taken to vc o;lt +4yel*be the direction that

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  
  A coulomb per second is the soy bcx2jpzifgs* l7:d 5u.d-,mbs70 dame as

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  
  Car batteries are rated in "amp-hoursxlo6+ s3y(owh 9 vk8ri." This is a measure of their

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  
  The resistance of a wirj(;(fi4pw okg7(p;ld rj2 r5d 2juyaie is defined as

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  
  What is $1 \; \Omega$ equivalent to?

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  
  The resistance of a wi)o2zinkf n ,p(0hnb -fre is

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  
  The resistivity of a wire dependsxz o36m3qrp+e )obka+ on

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  
  Which conducting material has the lowestg5+ti m , 2m0: kdw7z(vofxezk resistivity value?

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  
  Consider two copper cw62ofz*kg7f5 ne7hmj+0 mu 1slj w4hwires. One has twice the length of the other. How do the resistivities of these two wireshnk wz6g0727 wjlef+cm1jhf*mous 4 5 compare?

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  
  Consider two copper wires. One has twice the length of the other. Ho, :7 :t hzb:vsx-vh42 zncnsodw do the res sxbon4:cvh:v2-h7d s ,nz zt:istances of these two wires compare?

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  
  Consider two copper wires. One has twice the cross-sectional lz kd,ngch3,9area of the other. How do thehdc,g,nl 9k z3 resistances of these two wires compare?

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  
  Consider two copper wires. One has twice th x8wbya fgd27,je6.i; wdzo/xe length and twice the cross-sectional area of thy,6fxbd;/ gi82 xojw ewaz. d7e other. How do the resistances of these two wires compare?

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  
  The length of a wire is doubpl;iqqre 10fiud++ : 9ope3xiled and the radius is doubled. By what factor does the resistancei +d3i9qipu qeo rle+1:p; xf0 change?

参考答案:    
标记此题
17#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How much more resistance -gbl;yac9 ltn-n .m2hk*sr (z does a 1.0 cm diameter rod have compared to a 2.0 cm diameter rod of the samnzra m* - h ynkcl9ltsg.2(;b-e length and made of the same material?

参考答案:    
标记此题
18#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The resistivity of most common mg*g* r ys 7 dw*pk(a,q3njb;fnetals

参考答案:    
标记此题
19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  Negative temperature coefficiebghyp(2 ,9ns knts of resistivity

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  
  What is 1 W equivalentldvs 3 sz5ghju58m g2da. 6.qj to?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
21#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A kilowatt-hour is equivy v-ac2xp 2z0nb pj/82mqg*/zaa 2 kv(rwzfm9alent to

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
22#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the resistance in a co uzyyoqh5mz k ,u;(-,rg3.nkinstant voltage circuit is doubled, the power dissipated by thaz(u kk,h u5qnyi;.gm-3zro, yt circuit will

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  
  If the voltage across a circuit rl1+p j(0r mteof constant resistance is doubled, the power dissipated by tha1(0j+trrm lep t circuit will

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
24#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the resistance in a circuit with constant current flowing is doub;*uvn4 f8g(xjx2gyok sjmxq+x9 (k s8led, the powerjk *+n x8q9(;g yuxvmg4o x82s(jxfks dissipated by that circuit will

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
25#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  If the current flowing throud:d;a*l2rse layv1trg v7 a05gh a circuit of constant resistance is doubled, the powe1yarsd l5a :lar;ed v7g0v 2t*r dissipated by that circuit will

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  
  During a power demand, the voltage output y tsm4n4 +wdopwou: b8(*o e8his reduced by 5.0%. By what percentage is the power on est8( po*w8oh4:dou4n b mw +ya resistor affected?

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  
  A current that is sinusoidal with cbps1 bqr09 0qth/ xl,respect to time is referred to as

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  
  Consider two copper wires each carrying a current j7gmjm*/t0ojnog7 :*+m lbl g of 3.0 A. One wire has twice the diameter of the other. The ratio of the drift velocity in the smaller diameter wire to that in the larger diameter wire i gbjm0gnltojolgmm7 /7 j :+**s

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  
  Materials in which the resistivity becomg /7*hi4 oyfbnes essentially zero at very low temperatures are 4f yn7b/io* ghreferred to as

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  
  What current is flowing if 0.67 C of chargefc v eyx ,6rvm686p6sq pass a point in 0.30 s?

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 charge of 12 C passes through an e o b:cp;mw3m3 z9t2l admk.(qflectroplating apparatus in 2.0 min. What is the 332c ( q zmodtpkmb:9a mfwl;.average current?

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  
  How much charge must ybc upg w9ot; 0d)q;ked0rl8 xbv*k 1)pass by a point in 10 s for the current to be 0.50 A?

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 total of $2.0 \times 10^{13} \; protons$ pass a given point in 15 s. What is 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  
  What current is flowing i -qbrp vhph0qd4ja g25f-s. 1sf $4.0 \times 10^{16} \; electrons$ pass a point in 0.50 s?

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  
  If $3.0 \times 10^{15} \; electrons$ flow through a section of a wire of diameter 2.0 mm in 4.0 s, what is the current in the wire?

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 coffee maker, which draws 13.5 A of current, has been left ; h) oxfeu4)ieon for 10 min. What is the net nu )f4ohe xi;)uember of electrons that have passed through the coffee maker?

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  
  In an electroplating proc6akohp6+ t 6rcess, it is desired to deposit 40 mg of silver on a metal part by using a current of 2.0 A. How long must the current be allowed to run to deposit this much silver? (The silver ions are singly charged, and the atomic weight of silver is 1chrptoa+6k66 08.)

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  
  What potential difference is required tog:j*w zwnuz21rg 2kit g4iu*4 cause 4.00 A to flow through a resistance ofgnigit2: *uz ug* 1w4 jkrz42w 330 W?

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  
  What is the voltage across ah9k2fy w-/lrw 5.0-W resistor if the current through it is 5.0 A?

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  
  A 4000-W resistor is connected across 220 V. What current willhcse:t+-e j try 3,1epjb) ,kg flow?

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  
  A light bulb operating at 110 V draws 1.40 A of -h gjm tnxcl8* /plx3.d 0fxg2current. What is its resistance /0lxg-xc xhmd*jp2 lgt3.fn8?

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  
  A 12-V battery is connected topao, wf xhddf39in9 9i03+ bnh 4e*jjo a 100-W resistor. How many electrons flow through the n xijh*dej09,39b f wf h4on3id9+opawire in
1.0 min?

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  
  What is the resistance of 1.0 m copper wire of diameter 0.40 inch? (The dh h/q;,;f w,dsas-ehresistividsh,h,ha;/fsw qd e;-ty of copper is $1.68 \times 10^{-8} \; \Omega \cdot m$.)

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  
  What is the resistance of a circular rohnow:0 ukw5b n4y7b ;fd 1.0 cm in diameter and 45 m long, if the resistivity ob;bn y:hf0n kww57u4 is $1.4 \times 10^{-8} \; \Omega \cdot m$?

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  
  What length of copper wire (resistilx95 ctgj5p6oyvaewo 22( -ryvity $1.68 \times 10^{-8} \; \Omega \cdot m$) of diameter 0.15 mm is needed for a total resistance of $15 \; \Omega$?

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  
  A 120-m long copper wire (resistivhtx x/9 7 endq206rybgsgay+.ity $1.68 \times 10^{-8} \; \Omega \cdot m$) has resistance $6.0 \; \Omega$. What is the diameter of the wire?

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  
  A 1.5-cm square rod, 4.0 m long, measures 0.040 ov:lyhg1r iu g,sg-h;3hms. What is its resistivity?

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  
  Calculate the current through a 10.0-m long 22 gauge (the radius is 0.321 mm) n(d.5a sr9td.3rf ,vix :xnpchy, ol7 yichrome wire if it is connected to a 1,alxs r,5.y(i tdy cv3h.n 9 7pfxdor:2.0-V battery. (The resistivity of nichrome is $100 \times 10^{-8} \; \Omega \cdot m$.)

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
49#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A heavy bus bar is 20 cm long and of rectangular cross-section, 1nx9yr *; /-fkx4luac* 8m3 htpu9 maev.0 cm x 2.0 cm. What is the mp fn;9 rmuu9aay h*3lx e4 *vtkcx8/-voltage drop along its length when it carries 4000 A? (The resistivity of copper is $1.68 \times 10^{-8} \Omega \cdot m$)

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
50#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 1.0-m length of ni/ xdk+)stal 1ochrome wire has a radius of 0.50 mm and a resistivity of $100 \times 10^{-8} \; \Omega \cdot m$. If the wire carries a current of 0.50 A, what is the voltage across the wire?

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  
  A 1.0-mm diameter copper wire (jl81 xgp3 q00bsx6 erhresistivity $1.68 \times 10^{-8} \; \Omega \cdot m$) carries a current of 15 A. What is the potential difference between two points 100 m apart?

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  
  A carbon resistor has a resistancj09 .l fowexy0e of $18 \Omega$ at a temperature of $20 ^{\circ}C$. What is its resistance at a temperature of $120 ^{\circ}C$? (The temperature coefficient of resistivity for carbon is $-5.0 \times 10^{-4} /^{\circ}C$.)

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  
  The temperature coefficient of resistivi8 +i 78yy7kfyapjq 9hcty of platinum is $3.9 \times 10^{-3} /^{\circ}C$. If a platinum wire has a resistance of R at room temperature ($23 ^{\circ}C$), to what temperature must it be heated in order to double its resistance to 2R?

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 platinum wire is used to determine the meltint3e k+vs1(wo wg point of indium. The resistance of the pls(w+ k ovtwe31atinum wire is $2.000 \; \Omega$ at $20 ^{\circ}C$ and increases to $3.072 \; \Omega$ as indium starts to melt. What is the melting point of indium? (The temperature coefficient of resistivity for platinum is $3.9 \times 10^{-3} /^{\circ}C$.)

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  
  5.00 A is flowing throl,05-k0vj;d8cxd5 vozf jpk njig8i5ugh an $10.0 \; \Omega$ resistor. How much power is being dissipated?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
56#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 110-V hair dryer is rated at 1200 W. What current will it drav(,a y:5ja,w7ejri 3va .ouv l- nbae+w?

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 150-W light bulb running on 11)vi)ekzlvg9)9 (v+ rur) rf af0 V draws how much current?

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  
  What is the nominal ty4 j 5r 5vccfeu8s;l2resistance of a 100-W light bulb designed to be used in a 120-V ci25 c8v4yfj er5;tlsuc rcuit?

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  
  A toaster is rated 800 W atv atb42v bbs(-x*gg 2bu ye4g ;s/wt2u 120 V. What is the resistance of its heating elementbags/b (txw-42vg busu42 etgb *y ;2v?

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 200-W resistor is ratekt7jaqfrnwui :+8- r. d at $1/4 \; \Omega$. What is the maximum current it can draw?

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 200-W resistor is rated at-*lwm.v5q os9gac7;8sl xd rq $1/4 \; \Omega$. What is the maximum voltage?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
62#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A lamp uses a 150-W bulb. If ik gj 6zvfsz5(6t is used at 120 V, what current does it draw?

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  
  A lamp uses a 150-W bulb. If it is used at 120 rzmkq6+ +cyq 6V, what is its resistance?

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 25-W soldering iron runs o/t( : 10elfky h7wz(da+vmkpcn 110 V. What is its resistance?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
65#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How much does it cost to operate a 25-W soldering hp bn())bbf,c iron for 8.0 hours, if energy costsbh n)c,bfb p() $0.08/kWh?

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  
  How much energy does a 100-W light bulb i.h7 wpq3fn.nm cwu +)use in 8.0 hours?

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  
  A 1500-W heater is connected to a 120-V line for 2.0 hours.e.h )am)ni1pd.ms2h y How much heat energy is d y)n)him21hap..m e sproduced?

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  
  A battery is rated at 12 V and 160 A-,n 8gxec)- czrh. How much energy does the battery store?-rz8exc,c gn)

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
69#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  How much energy does a 2zrjm-twcc760jk j *.k 5-W soldering iron use in 8.0 hours?

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  
  A 100-W driveway light bulb is on 10 houre0md: +g,dzqds per day. Assuming the power company charges 10 cents for each kilowatt-hour of electrimz gd0eq,+dd:city used, estimate the annual cost to operate the bulb.

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  
  A 400-W computer (computer plus monitor) is turned o:7yca40qhn1mtdpn f( n 8.0 hours per day. If electricity costs 10 cents per kWh, how much does it cost to run the computer ac:pt0fmdan 1 h(qn47y nnually?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
72#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  The monthly (30 days) electric bill included the cosc7wca n 8vew81 (pv2elt of running a central air-conditioning unit for 2.0 hr/day at 5000 W, and a series connection of ten 60 W light bulbs for 5.0 cw 1e78l82cvenva p w(hr/day. How much did these items contribute to the cost of the monthly electric bill if electricity costs 8.0 cents per kWh?

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  
  The heating element in an electric drier operates on 240 tig (+hxxg7(oV and generates heat at the rate of 2.1 kW. The heating element shorts out and, in repairing it, the owner shortens the Nichrome wire by 10%. (Assume the temperature is unchanged.7(o itg hxxg(+ In reality, the resistivity of the wire will depend on its temperature.) What effect will the repair have on the power dissipated in the heating element?

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  
  14 A of current flows throp0wym,bbf( n9od 8q d/vh9 3-.r aatrough $8.0 \; \Omega$ resistor for 24 hours. How much does this cost if energy costs $0.09/kWh?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
75#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 9.0-V battery costsz*a lix0*t6hg $1.49, and will run a portable CD player for 6.0 hours. Suppose the battery supplies a current of 25 mA to the player. What is the cost of energy in dollars per kWh?

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 motor that can do work at the rate of 2.0 yu3r*h.xj r,ep2 u uf/hp has 60% efficiency. How much current does it draw from a 12pu, x/*3 u.2e furyhrj0-V line? ($1 \; hp = 746 \; W$)

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  
  A 500-W device is co,hf/:0 yeh3iy lfbb/gnnected to a 120-V ac power source. What rms current flows through this de iy/gyf:l3bfe hh,0 b/vice?

参考答案:    
本习题练习题目来源于51fly国际课程 (https://51fly.win)，学生可刷题练习，扫右侧二维码或加微信xxxxxxxxxx，获取更多资料
教师可以抽题组卷或一键复制本试卷，布置为在线考试或在线作业，全自动判分成绩一键排序导出，省时省力
标记此题
78#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  A 500-W device is connected to a 120-V ac power m6ahmxyvs-w):c2 4fum :5bz 7)q mosvsource. What peak current flows through shc7qbu:mvv)fm)5 aws6y-mm4z o:x2this device?

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  
  A 500-W device is connecte-sd .1 :qm890w.adz orimmzgid to a 120-V ac power source. What is the peak voltage across this:m.zro0 mwqz s ig.d8ai dm91- device?

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  
  The diameter of a copp. nweq8;qyt9 edh pc2*er wire is 0.081 inch. The maximum safe current it can carry (in order to prevent fire danger in building construction) is 20 A. At this current, what is the drift velocity of the electrons? (The number oytp.*qcw9 ;2e dhqen 8f electron carriers in one cubic centimeter of copper is $8.5 \times 10^{22}$.)

参考答案:    
  • 姓名:游客(未登录)
    •
    总分:80分 及格:48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 80 道题

    试卷内容到此结束!   © 2025 51fly国际课程 (https://51fly.win)版权所有

    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, 2025-12-20 11:01 , Processed in 0.419567 second(s), 190 queries , Redis On.