A.用刻度尺测量金属丝全长,且测量三次,算出其平均值,然后再将金属丝接入电路中 |
B.用螺旋测微器测金属丝测量一次直径就可以 |
C.用伏安法测电阻时,采用电流表内接法,多次测量后算出平均值 |
D.实验中应保持金属丝的温度不变 |
2 . 为测量某金属丝的电阻率,某同学设计了如图甲所示的实验电路图。
(1)该同学首先用米尺测出接入电路中金属丝的长度L,再利用螺旋测微器测量金属丝直径,测量结果如图乙所示,金属丝直径的测量值。
(2)为使闭合开关时,电压表、电流表示数均为零,滑动变阻器的滑片P应置于
(3)利用伏安法测该金属丝的电阻R,代入关系式等表示)。
(4)由于电表内阻的影响,实验会产生
(1)现有电源(12V,内阻忽略不计)、滑动变阻器(0~50Ω,额定电流2A)、开关和导线若干,以及下列电表:
A.电流表(0﹣3A,内阻约0.01Ω)
B.电流表(0﹣0.6A,内阻约0.05Ω)
C.电压表(0﹣3V,内阻约600Ω)
D.电压表(0﹣15V,内阻约3kΩ)
为减小测量误差,在实验中,电流表应选用
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/15/4b78aac3-5cde-40ac-956d-b5f4524a7de0.png?resizew=300)
(2)实验中记录电表示数如图所示,可得该电阻的测量值Rx=
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/15/fcb296a1-77e6-4d10-a17b-e454f30279ad.png?resizew=470)
(3)本实验中选用电路产生系统误差的主要原因是
A.电流表的分流作用 B.电流表的分压作用
C.电压表的分流作用 D.电压表的分压作用
(1)用螺旋测微器测量金属丝的直径,其示数如图甲所示,则该金属丝直径的测量值d=
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/8/28f7abb2-3cb1-4f2b-a251-b56422f7ee02.png?resizew=333)
(2)按图乙所示的电路图测量金属丝的电阻Rx(阻值约为15
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
电压表V(量程0~3V,内阻约3k
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
电流表A(量程0~200mA,内阻约3
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
滑动变阻器R1(0~50
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
滑动变阻器R2(0~200
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
电源E(3V,内阻不计)。
为了调节方便,测量准确,实验中滑动变阻器应选
(3)请根据如图乙所示的电路图,用笔画线代替导线将图丙中的实验器材连接起来,并使滑动变阻器的滑片P置于b端时接通电路后的电流最小
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/8/0318968f-4901-456d-a103-d479f040fc0f.png?resizew=297)
(4)若通过测量可知,金属丝的长度为l,直径为d,通过金属丝的电流为I,对应金属丝两端的电压为U,由此可计算得出金属丝的电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
(1)用螺旋测微器测量其横截面直径,示数如图甲所示;用游标卡尺测其长度,示数如图乙所示。则读数结果正确的是( )
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/9/9068e4a3-730b-4fa0-8772-cb33fe5ab860.png?resizew=316)
A.1.420mm,40.40mm | B.1.420mm,40.4mm |
C.0.920mm,42.4mm | D.0.920mm,42.40mm |
①电压表V1(量程3V,内阻约为3kΩ) ②电压表V2(量程15V,内阻约为15kΩ)
③电流表A1(量程100mA,内阻约为10Ω) ④电流表A2(量程0.6A,内阻约为2Ω)
⑤滑动变阻器R1(0~5Ω) ⑥滑动变阻器R2(0~200Ω)
⑦电动势为3V的电源,内阻不计 ⑧开关S,导线若干
该实验要求待测电阻两端的电压能从0开始调节。为准确测量其电阻,电压表、电流表、滑动变阻器应选:对应器材前的序号组合为:( )
A.①④⑤ | B.②③⑥ | C.①③⑤ | D.②④⑥ |
A.![]() | B.![]() |
C.![]() | D.![]() |
6 . 李同学要测量新材料制成的圆柱体的电阻率ρ,步骤如下:
(1)用游标卡尺测量其长度如图甲所示,由图可知其长度为L=
用螺旋测微器测量其直径如图乙所示,由图可知其直径D=
(2)彭同学用多用电表粗测圆柱体的阻值:当用“×100Ω”挡测量时指针偏转角过小,为提高测量的精确度,应换
(3)马同学想用伏安法测量其电阻,设计了一个如图所示的电路图。请你从安全性、精确性等角度评价这一方案,并指出一条该方案可能出现的问题
(1)用螺旋测微器测量金属丝的直径,其示数如图(甲)所示,则该金属丝直径的测量值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/11/f25c3f8e-fcb5-43c0-be07-c55da25138dc.png?resizew=344)
(2)按如图(乙)所示的电路图测量金属丝的电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b49bd50cc6fc1307c907c8e5bc953de.png)
电压表V(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a6bb65878785532d817f8fd11a9ef3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad53b547e11f3e4719a70a4b9564cc8.png)
电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9702bcd681a78217cac07885c030677c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/493dfb76b4214b676a9f06f0be1f4b4e.png)
电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b5c929172bbfc21741fa7ef1f53b7bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0303b4d79507a7b7c1dccaecaebff5ef.png)
滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/065330d2cb4d703ddb731467964fb801.png)
滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48169f1d9df77dba2aa4b1102f4446e7.png)
电源E(电动势为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
为了调节方便,测量准确,实验中电流表应选
(3)请根据图(乙)所示电路图,用笔画线代替导线将图(丙)中的实验器材连线补充完整,并使滑动变阻器的滑片P置于b端时接通电路后的电流最小
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/16/6db6fe81-af4e-4523-8edb-1d8927ead650.png?resizew=220)
(4)若通过测量可知,金属丝的长度为l,直径为d,通过金属丝的电流为I,金属丝两端的电压为U,由此可计算得出金属丝的电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/10/13314d5b-f791-4a24-b568-8e0dedc9cf20.png?resizew=326)
(1)利用螺旋测微器测定合金丝的直径,示数如图(a)所示,则可读得合金丝的直径为
(2)待测合金丝
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeac921b936467bb4a262537616cfac2.png)
A.电压表V(内阻约为10kΩ,量程为3V)
B.电流表A1(内阻约为3Ω,量程为0.6A)
C.电流表A2(内阻约为0.1Ω,量程为3A)
D.滑动变阻器R(阻值为0~5Ω,额定电流为2A)
E.电源E(电动势为5V,内电阻为1Ω)
F.一个开关、若干导线
①要求较准确地测出其阻值,电流表应选
②请根据以上仪器,设计实验电路图,并在图(b)中完成电路图的实物连线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e2a1c3ce654fd5fcaa3311ebfe9889d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/8/706eddd8-df24-4214-821d-7889945677dc.png?resizew=340)
(2)用螺旋测微器测量一根金属丝的直径,如图2所示的读数是
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/8/59a6d56d-dc0c-4067-b026-8da951dbb81f.png?resizew=120)
(3)为了测量金属丝的电阻率,某同学先用多用电表粗测其电阻.用已经调零且选择开关指向欧姆挡“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d55519bd96aba05e6f1533ddc7bb63fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eebdb972b35aaa81a6662aaf8db1c282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3a1e976dc7ccea4600a8ad1121760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/8/099eb6b5-3aa1-4bb9-885e-4de6f28f26ec.png?resizew=387)
(4)然后较准确测量金属丝的电阻,除待测金属丝外,实验室还备有的实验器材如下
A.电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46ad1a9cd19361d1f7a2340d76d50c80.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/549b8489b17608927e9ba3f6d2da1f16.png)
B.电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b40f1d184152aa3954752ed70e7d1612.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deb4bcbd9cbba7000bf5154da782db51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c2ab5e570e63c28918742f29cb47c69.png)
C.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9d1ce44013cb5ba7c6038dabc2803d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910928687da37388715dd531939fbfed.png)
D.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f4b494c018e878f391bebe256622e76c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db144c76e36b0c4d950698b2bbc39f9.png)
E.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e9d347b229aca897344d2afa080cba1.png)
F.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19c7134b3e352b21e6129ed01c6a8d45.png)
G.输出电压为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41d8b94b084bbad77f6571673d8ccc19.png)
H.开关S,导线若干
实验中应选用的电压表是
(5)要求实验误差较小,并且电压可以从0开始调节,请在虚线框内设计最合理的电路图
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/8/ef83d348-7ef7-410f-8821-1af4eba1a054.png?resizew=199)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/5c567772-794e-4205-bba0-78962ea3ab9b.png?resizew=205)
(1)用游标卡尺测量有效长度时,测得的结果如图所示,则长度
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd1846e964fd60c54888a3c706a97442.png)
(2)她先用多用电表的欧姆挡粗测,发现用“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2468403b3eba9e40bfa36f464e927738.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2468403b3eba9e40bfa36f464e927738.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/4df9432f-3950-4047-9bc7-5082538de8b1.png?resizew=339)
(3)用改换倍率后的欧姆挡测得待测电阻大致阻值如图,现备有下列器材进行进一步测量:后用伏安法更精确地测量其电阻Rx,要求测量数据尽量精确且电压从零开始增加,可供该同学选用的器材除开关、导线、待测电阻Rx外还有:
A.直流电源(24V)
B.电压表(量程0~15V,内阻约10kΩ)
C.电压表(量程0~50V,内阻约50kΩ)
D.电流表(量程0~10mA,内阻约为100Ω)
E.电流表(量程0~25mA,内阻约为30Ω)
F.滑动变阻器(最大阻值50Ω)
G.开关和导线若干
为了保证实验顺利进行,并使测量误差尽量小,电压表应选
(4)本实验的测量电路适合用电流表的
(5)由于电表内阻的影响,Rx的测量值较真实值