无忧得胜-网上国际课程 (5edu.win)

 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

Switch to Full Screen

习题练习：Electricity and Circuits: Resistor
本习题练习试卷来源于无忧得胜-网上国际课程 (https://5edu.win)， 为试卷打印版，您也可以在网站平台(https://autodiscover.5edu.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 527，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://autodiscover.5edu.win/test527.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: admin  发布日期: 2026-05-21 08:55    总分: 50分  得分: _____________

答题人: 游客未登录  开始时间: 24年08月22日 11:12  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  
  16.09: In the circuit shown, an electric current exists in the metave89 m pavo1y-136 zxm. )ubjfpkhuf 4l resistor connected to the battery. Which one of the following choices best describes the direction of electron flow through the resistor and the direction of the electric field va). pjk311f9omxvum8 bzp-h4 yfe6uthrough the interior of the resistor?


参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
2#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  98.06: When any four resistors are connected in parallel, the_________eaflkxggw,/1 sipd+ : +*qzk 6ilch resistor is t xzp1gi6k*k+i,+s :l wgdqf/l he same.

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  
  06.33: A current through the thin filament wire of a lightbulb causes the fila8huuewv ey (r)pjx9af ,; u(p1ment to becomej u;(u,hrxewe )p yuf1ap(9v8 white hot, while the larger wires connected to the lightbulb remain much cooler. This happens because

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  
  13.08: Some standard household,ep p)wu4 rzcd7o:(qec +)7sg pk rii. lights are being replaced with LEDs. LED is the acronym for which ones )ezd c ,i:r)oikcp4uw p7(q7gr+pe. of the following choices?

参考答案:    
标记此题
5#
 
多选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  05.16: A cylindrical graphite resistor has length L x2ow. 3-ogj nr hi,e6dand cross-sectional area A. It is to be plio6.jnrehd wo,3 x2-gaced into a circuit, but it first must be cut in half so that the new length is 1/2 L. What is the ratio of the new resistivity to the old resistivity of the cylindrical resistor?

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  
  98.20: Wire I and wire II are made of the sa xbf9o9*vnncgi/r* 9huvo3 +mme material. Wire II has twice the diameter andbf/n iv9n*3rcv+h *x m g9uo9o twice the length of I. If I has resistance R, II has resistance

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  
  99.31: Wire Y is made of the same material but has twice the diameter and h)*tvx gy8*jnlj gf:9malf the length of wire X. If wire X has a resistance of R then wire Y would hjtljy8n) g *m9v:fgx*ave a resistance of

参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
8#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  03.23: A cylindrical res )sny, fxpzw9 c6z.a6sistor has length L and radius r. This piece of material is then drawn so that it is a cylinder with new length 2L. Wha czspnfz9a x.6s),6wyt happens to the resistance of this material because of this process?

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  
  07.27: A junior Thomas Edison t4)-z8e bsf2f.zzsvke ..c xf wants to make a brighter light bulb. He decides to modify the filament. How should the filament of a lightbulb be modified in order c e)tsz.-2f. f xz.4bfvz8eskto make the lightbulb produce more light at a given voltage?


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  
  16.07: Three cylindrical resistors are made of the same material. The leng3o ydp9s. 9n3cdes7ygth and radius of eac . ecsn9y39p s7d3odgyh resistor is:
Resistor 1: Length L, radius r
Resistor 2: Length L/2,radius r/2
Resistor 3: Length L/4,radius r/2
Which one of the following choices correctly ranks the resistance of these resistors (R1,R2,R3)?

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  
  13.22: Four resistors, each of resistance R, are connected -is/9x*98xmitbeq wm to a battery in the following way: “Two resistors are connected in series. This combination of two resistors is connected in parallel to a third resistor. This set of three resistors is connected in series to a fourth resistor.” What is the equivalent resistance9*qxms bt /-x8iewmi9 of this arrangement of four resistors?

参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
12#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  95.35: The voltmeter igqz0bm b bby;x,xo)87 h4tr g5n the accompanying circuit diagram has internal resistance 10.0 kW and the ammeter has interg,bb48x);o hrxzm5qy b07 gbtnal resistance 25.0 ohm. The ammeter reading is 1.00 mA. The voltmeter reading is most nearly:


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  
  97.37: Consider the compound circuit shown to the right. Th8wc;-0 (1 :fo i dvrnal8umovyz g1b0de three bulbs 1, 2, and 3 -(gw nzdoulo- y0:v08dr8 a1; mivfbc1 represented as resistors in the diagram
- are identical. Which of the following statements are true?
I. Bulb 3 is brighter than bulb 1 or 2.
II. Bulb 3 has more current passing through it than bulb 1 or 2.
III. Bulb 3 has a greater voltage drop across it than bulb 1 or 2.


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  
  99.30: Given the simple electrical cirrxk s*4zy7ad3. u prnqyd:y 41cuit at the right. If the current in all three resistors x*4 pz.adny1s7 r4rdy3:yku qis equal, which of the following statements must be true?


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  
  99.37: The diagram at rhxa+ /k4bjrljp .:e+v ight represents a simple electric circuit composed of 5 identical liv4.x / ablk p:+e+jrjhght bulbs and 2 flashlight cells. Which bulb (or bulbs)
would you expect to be the brightest?


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  
  00.03: Which of the following state i*rv t-jh*c-b4t *ppbvpw *+jtvar-9ments is NOT true concerning the simple circuit shown where resistors R1, R2 and R3 are have equal resistan vbw-4-9j-pi*h*tt* trpjv pbcra* +v ces?


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  
  17.29: Two lightbulbs X andY are clq1wx9( stxe9 :a54ih2 +d+ r nuffjtyonnected in series to a battery. Bulb X is brighter than bulb Y. Assume all circuit elements are ideal. If bulbs X andY are connected in parallel with each other to the same battery, which one of the following choices bestut: f+ntlwrx(sh djia2q99e5 f41+x y represents what is observed?


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  
  06.34: How many coulombs will pass throung8ty 0lbg4 h:gh the identified resistor in 5 seconds once the circuit was closed? 48 gbh:y 0glnt


参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
19#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  00.23: If all of the resistors in the followin.c/ g;wkkp 6ulg simple circuit have the samec6./gwlupk k; resistance, which would dissipate the greatest power?


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  
  98.34: In the accompanying circuit diagram, 7tercd n:f3h z u -p15wzfn4e1the current through the 6.0 Ω resistor is 1.0 A. What is the po7ew4p-fcnr1f nd zhze 35u: 1twer supply voltage V?


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  
  97.27: Three resistors R1, R2, and s27l g(qjk0ew3j osg)R3 are connected in series to a battery. Suppose R1 carries a current of 2.0 A, R2 has a resist)qe0sos jwj(l7 k2gg3ance of 3.0Ω, and R3 dissipates 6.0 W of power. What is the voltage across R3?

参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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  
  99.40: Three different resistors R1, R2 andR3 are connected in parallel to a ba/gxfb ozjkl g- /r1dn912q+jz tte-jjnzq +lo1kr/b/ dgzgf129 xry. Suppose R1 has 2V across it, R2 = 4Ω, and R3 dissipates 6 W. What is the current in R3?

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  
  99.13: A heating coil is rated 1200 watts and 120 volts. *zg.+kh leqwbeyyq bq .;l+*ier+v:/ ,wnx l; What is the maximum value of the current under these conditqq+ ;v+lh* iq y/; :,bry+ *wnxk. bee.ezlwglions?

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  
  99.23: What is the resistance of a 60 wav38qi 4ji87cibh ,vszjo.de ,tt lightbulb designed to operate at 120 volt,j.dsizv 88 j h3i 7bqi,oevc4s?

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  
  03.09: How much current flows through a 4 ohm resistor that is dissxlj0iz1kcrxr7f 4 : m9ns64hhipating 36 watts :fj6mlz74nxr9hhs0cik rx1 4 of power?

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  
  05.21: A household iron used to press clothes is marked "120 volt, 600 w/plz30.o6p)de gxaaor*i v 2eatt.” In normal use, oiaz. oel e*2)/rpxg3p06v adthe current in it is

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  
  01.05: Which of the following resistances could NOT be produceds lgm* stjmjji(344z( by a circuit containing o4( j34jzlstgs*mm j i(nly three identical 6Ω resistors?

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  
  94.37: You are given threed5me mu*2v*iqb h2 4ot 1.0 Ω resistors. Which of the following equivalent resistances CA4hvmi qtom*ub 2*52edNNOT be produced using all three resistors?

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  
  02.06: Three resistors of different g 1dgm4xu a.k yna;o (ak2)hq-values can be connected together in different configurations. If all three resistors are used in a circuit, how many difq)1ud(a42mx gkkhoa y.;-nag ferent values of total resistance can be produced?

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  
  97.35: When a single resistor is connected to a battery, a t4 .tf k ,bnemtu+j:)fxotal power P is dissipated in the circuit. How much total power is dissipated in a circuit if n identical resistors are connected +k)te tff .4n,jbmux: in series using the same battery? Assume the internal resistance of the battery is zero.

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  
  96.16: When two resisto +9riu/jbj 3 ajcu(-tjrs, having resistance R1 and R2, are connected in parallel, the equivalent resistance of the combination is 5Ω . Which of the following statementsjj /+9-(j iu3rjubtac about the resistances is correct?

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  
  02.46: A hotplate is designed such that it has a resistyoa)9zh fuzdy ,-09cgs v-b- g+ 2syvxance of 12Ω when operating at 120 volts. Wgy0ydav)x9zcs -s+2h-yg , vu-zf ob 9hat is the minimum amount of time that it would take to warm 0.45 kg of water from $15^{\circ}C$ to$85^{\circ}C$?

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  
  03.09: How much current flows through a 4 ohm resistor that is dissipatinp32sj9 z yd64tuicy/sg 36 watts 2 y3ptz6sis/4 9yudcj of power?

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  
  01.24: An electric heater draws 13 amperes o.qzt7dhz1 2ptbq: 19 0yrhefl f current when connected to 120 volts. If the price of electricitb 7hf1hqt.:pl01 edz9y2q zr ty is $0.10/kWh, what would be the approximate cost of running the heater for 8 hours?

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  
  08.05 Approximately how much would it cost to keep a 100W lightbulb lit continmx+ 6nao.n8xb uously for 1 year at n8om +6a.bxnxa rate of $0.10/(kW.hr) ?

参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
36#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  12.09: A constant current of 4n*ns06c)bdj rwh 72w;i b bu2o.00 A through a lightbulb results in a power of 24.0 W associated jbcrw0 h7o)6;22bw ndisnb* uwith the bulb. Which one of the following choices best represents the resistance of the lightbulb?

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  
  01.10: Each member of a family of six owns a computer rated at 500 watts in t+tr 8eth7juytvq9)7h b-cg u,ft v31a 120 V circuit. If all computers are plugged into a single circgjf1tcrhueht) tq, 73tu-+8 7b tvv9y uit protected by a 20 ampere fuse, what is the maximum number of the computers can be operating at the sametime?

参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
38#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  03.16: A 9-volt battery tiuw u6lx874b qyw/(pis connected to four resistors to form a simple circuit as shown to the right.bi6 p/uuw4xyl87(tqw
How would the current through the 2 ohm resistor compare to the current through the 4 ohm resistor?


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  
  03.17: A 9-volt battery is connected to fv 4x8bds)pj*x our resistors to form a simple circuit as show)x8j v bsp*x4dn to the right.
What would be the potential at point B with respect to point C in the above circuit?


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  
  02.21: An ideal battery, an ideal ammeter, a swit )vzm.5elofw( rzta icgfj9i1s 7r/:9 ch and three resistors are connected as shown. With the switch open as shown in the diagram the ammeter reads 2.0 a /az oijgwets95zffci.m 79 r1(:)rvlmperes.
With the switch open, what would be the potential difference across the 15 ohm resistor?


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  
  02.22: An ideal battery, an ideal ammeter, a switch anbgi iwql *2*w,6d9tu pd three resistors are connected as shown. Wit q l2i*, gwtdbu69*ipwh the switch open as shown in the diagram the ammeter reads 2.0 amperes.
With the switch open, what must be the voltage supplied by the battery?


参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
42#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  02.23: An ideal battes pl eag,rdi rlg*p+1ogrih/ g+/4 0,zry, an ideal ammeter, a switch and three resistors are connected as shown. With the switch open as shown in the diagram the ammeter reads 2.0 a*rlp/ 4ggzi s ++/d,hrpl oi, ar0eg1gmperes.
When the switch is closed, what would be the current in the circuit?


参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
43#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  12.14: For the circuit shown to the right, what is the equivalent resistance? ;azgv wwi2e 6jw8/wq3 Assume that all wires are ideal, the battery has no internal resistance, and all three resistors hqia3wwge zwj;6 /28vwave identical resistance 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  
  09.07: The equivalent resistance of the circuit shown to the right with r w+x0)k5cset) cwtq2pesists2e+w0t5p)cq) k twc xances $R_1 = 4.00Ω$ , $R_2 = 3.00Ω$ and $R_3= 2.00Ω$ is


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  
  04.20: The diagram below shows five identi :uneu9wy2 ,n)inkc. jcal resistors connected in a combination series and par2 ku:n nju,wi 9)n.eycallel circuit to a voltage source.
Through which resistor(s) would there be the greatest current?


参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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
46#
 
单选题 ( 1.0 分) 切至整卷模式 搜藏此题  
  04.21: The diagram bel nacxz6huesd.tf,6, 8/vcco+ ow shows five identical resistors connected in a combination series and parallel circuihfnv,xotcacz,c .6sedu /8 +6t to a voltage source.
Which resistor(s) have the greatest rate of energy dissipation?


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  
  07.29: In the circuit diagram, all of 1fa+z)g hpv 85tao8lb 2itfb ,c-sig( the bulbs are identical. Which bulb will be the brig8)a8g2cfih(5ot,l ipg a b1- bzf+ vsthtest?


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  
  02.21: An ideal battery, an ideal ammeter, a switch and threega(pu-r ta a ,t.9e+ 5wzk7ivlay)b1 p 8gl4bt resistors are connected as shown. With the switch open as shown in th.ip+,wa4 bl tby -rka7)gtz8 vugte9 p1a(5ale diagram the ammeter reads 2.0 amperes.
With the switch open, what would be the potential difference across the 15 ohm resistor?


参考答案:    
本习题练习题目来源于无忧得胜-网上国际课程 (https://5edu.win)，学生可刷题练习，扫右侧二维码或加微信skysky1258，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  
  02.22: An ideal battery, an ideal ammeter, 8- 6 .w6wzqg;acnjhhza switch and three resistors are connected ah; z6c g8 6wwhj-azqn.s shown. With the switch open as shown in the diagram the ammeter reads 2.0 amperes.
With the switch open, what must be the voltage supplied by the battery?


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  
  02.23: An ideal battery, an ideal ammeter, a switch and three rl m(6mik*xox+;l 6 lguesistors are connected as shown. With the+xml iomkl;l *6u6xg( switch open as shown in the diagram the ammeter reads 2.0 amperes.
When the switch is closed, what would be the current in the circuit?


参考答案:    
  • 姓名:游客(未登录)
    •
    总分:50分 及格:30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 50 道题
    本平台(https://autodiscover.5edu.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

    试卷内容到此结束!   © 2026 无忧得胜-网上国际课程 (https://5edu.win)版权所有

    浏览记录|手机版试卷|使用帮助|手机版|无忧得胜-网上国际课程 (https://5edu.win)

    GMT+8, 2026-6-1 01:06 , Processed in 0.722417 second(s), 129 queries , Redis On.