电流表A1(量程0~100mA,内阻为5Ω);电流表A2(量程0~0.6A,内阻约0.3Ω);定值电阻R1=55Ω;
滑动变阻器R(0~5Ω);开关一个、导线若干。
(1)螺旋测微器示数如图甲所示,可知金属丝直径为
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/27/c13ed09f-650e-4ee3-b850-b4c11c62790d.jpg?resizew=466)
(2)若想更加精确地测出金属丝的电阻,请设计出测量电路图,并标明所用器材符号。要求使用提供的全部器材,能够测量多组数据,测量尽量准确
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/27/896c8f7c-8e77-4bee-bf33-97ed38de06e0.png?resizew=200)
(3)按照所设计出的测量电路,在某次测量中获得的数据如图乙所示,则电流表A1的示数为
(4)由以上所测的数据可算得金属丝的电阻率为
相似题推荐
(1)某次实验,在槽中倒入适量的盐水,水面的高度为4.50cm,用多用电表的电阻挡粗测玻璃槽中盐水的电阻,选择开关置于“×100”挡,发现指针如图甲所示,则该同学接着需要做的实验步骤是换选
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/24/6fb6e0a6-4709-4e1f-8dd7-f8de2d6ede6c.png?resizew=433)
(2)为了准确测量电阻,准备了以下实验器材:
A. 电动势为3V的电源,内阻约为0.5Ω
B. 电动势为15V的电源,内阻约为0.9Ω
C. 阻值为5Ω的滑动变阻器
D. 电压表3V挡,内阻约为3kΩ
E. 电压表15V挡,内阻约为5kΩ
F. 电流表15mA挡,内阻约为1Ω
G. 电流表0.6A挡,内阻约为0.5Ω
实验中要求尽量减小系统误差,应保证电表在测量时其最大读数超过量程的1/2,则电源应选择
(3)准确连线后,测出玻璃槽中盐水的高度为H,电压表示数为U,电流表示数为I,改变玻璃槽中的盐水高度,测出如表所示的5组数据,分析数据后,试通过
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1de70666e867a6f5c7b835971a03abf7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9942091e83e1d59af01f499a0caee212.png)
次数 | 水面高H(cm) | 电压U(V) | 电流I(A) |
1 | 2.53 | 2.88 | 8.7 |
2 | 3.00 | 2.65 | 9.5 |
3 | 3.51 | 2.63 | 9.8 |
4 | 4.00 | 2.35 | 10.9 |
5 | 4.50 | 2.52 | 13.1 |
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/24/944a0e40-8405-4c4f-82eb-01aaa46205d0.png?resizew=293)
![](https://img.xkw.com/dksih/QBM/2021/11/30/2862499885228032/2863409720049664/STEM/b4777b91-b231-4541-ad15-ff5cfd09b4a2.png?resizew=496)
待测热敏电阻RT(在实验温度范围内,阻值约几百欧到几千欧);
电源E(电动势1.5V,内阻r约0.5Ω);
电阻箱R(阻值范围0~9999.99Ω);
滑动变阻器R1(最大阻值20Ω);
滑动变阻器R2(最大阻值2000Ω);
微安表(量程100μA,内阻等于2500Ω);
开关两个,温控装置一套,导线若干。
(1)为了更准确地测量热敏电阻的阻值,滑动变阻器应选用
(2)请用笔画线代替导线,将实物图(不含温控装置)连接成完整电路
![](https://img.xkw.com/dksih/QBM/2021/11/30/2862499885228032/2863409720049664/STEM/1f51febd-2e4c-4ea2-90f3-078fdec771fa.png?resizew=255)
(3)下列实验操作步骤,正确顺序是
①调节电阻箱,使微安表指针半偏
②保持滑动变阻器滑片P的位置不变,断开S2
③记录温度和电阻箱的阻值,处理数据
④调节滑动变阻器滑片P的位置,使微安表指针满偏
⑤连接电路,闭合S1、S2
(4)某温度下微安表半偏时,电阻箱的读数为6000.00Ω,该温度下热敏电阻的测量值为
(5)多次实验后,实验小组绘制了如图乙所示的图像。由图像可知,该热敏电阻的阻值随温度的升高逐渐
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8403e6940486b8bce6e2a02e32fac789.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8c56c87fd6bf8a44244ba51a9d244e22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0460c2de36d4f82e635439e39eae375a.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/12/27/06a1a380-88f1-4373-88be-fe3bd6bf6d44.png?resizew=445)
现有如下实验器材:
①量程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/951f5dfc2ee88b950c0a4322d9236ce4.png)
②量程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db586f2c37b26089713ff02346e6d0d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d0210026c88ec845716829b24ecc77f.png)
③阻值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b65177eb9c7ace11b185dec72574949.png)
④内阻可忽略、输出电压为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
⑤阻值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e85fec54893a094a1e9817e8c4ba06e1.png)
小芳采用伏安法测量电线电阻,正确连接电路后,调节滑动变阻器,电流表的示数从0开始增加,当示数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49d5cc04bb7b7475c207ca95cdcef642.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/478abdd84506a8ef759e353a238db6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
可供选择的实验器材如下:
待测滑动变阻器(30Ω 1.5A);
游标卡尺(20分度);
电流表A1(量程600mA,内阻1Ω),电流表A2(量程3A,内阻约0.12Ω);
电压表V1(量程3V,内阻约3kΩ),电压表V2(量程1.5V,内阻约2kΩ);
电源(电动势为3V,内阻未知);
电键及导线若干。
![](https://img.xkw.com/dksih/QBM/2022/2/24/2930283768545280/2930929364541440/STEM/3aecfd7e-92c6-4aed-ba9c-957df7c09fd8.png?resizew=643)
为了避免损坏滑动变阻器,该同学决定不对滑动变阻器进行拆解,而是进行了如下操作:
(1)该同学首先用游标卡尺测量了电阻丝螺线管的长度
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9dfb7c0a3c4a19aad90ff55e1d6158d3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
(2)实验电路如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b52b4f24969673c863b5aff4fb6751ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e105760638b22b26ff8bec4354255e4c.png)
(3)分别以“
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b763290c8cb341f8c5b268ccc22e61bc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f0a532e15e232cb4b99a8d4d07c89575.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/54a5d7d3b6b63fe5c24c3907b7a8eaa3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18f0281e6bbdbe08beeccb55adf84536.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60fc6b72ffd68974aac1437153063a4e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e7054df2cf4aa5fb5136161518b7dd5.png)
![](https://img.xkw.com/dksih/QBM/2021/11/7/2846248565612544/2846366576238592/STEM/da6a2e8e-df8d-4a38-8c3c-d29f11b791e2.png?resizew=368)
![](https://img.xkw.com/dksih/QBM/2021/11/7/2846248565612544/2846366576238592/STEM/92184248-2e62-44be-be7d-66612d1d963b.png?resizew=367)
(1)实验中用螺旋测微器测得电阻丝的直径如图乙所示,其示数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
(2)实验时闭合开关,调节滑片P的位置,分别测量出每次实验中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e8ab1389172dd2c66d257b407d466e.png)
![]() | 0.10 | 0.20 | 0.30 | 0.40 | 0.50 | 0.60 |
![]() | 0.49 | 0.43 | 0.38 | 0.33 | 0.31 | 0.28 |
![]() | 2.04 | 2.33 | 2.63 | 3.03 | 3.23 | 3.57 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271552971f5fc28dfa881f15bcfa8ddd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd707b69a11f8de5566f23c1a2a9ff5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebda2a68ab386360b9bdf8223d9a032.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271552971f5fc28dfa881f15bcfa8ddd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258e40e3883271c3580c1d3c805dcac6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0cb9ad1e34877b0db02d0219332b0f7b.png)
【推荐3】某同学想测如图(1)集成电路里很薄的方块电阻的电阻率ρ,同时测干电池的电动势E和内阻r,他设计了如图(2)的电路。已知方块电阻的上、下表面是边长为L的正方形,上下表面间的厚度为d,连入电路时电流方向如图(1)。
①断开开关K,闭合开关S,改变电阻箱R阻值,记录不同R对应的电压表的示数U;
②将开关S、K均闭合,改变电阻箱R阻值,再记录不同R对应的电压表的示数U。
(1)画出步骤①②记录的数据对应的随
变化关系的图像分别对应如图(4)的两条图线,横截距分别为
、
,纵截距为
、
,请判断哪条是步骤①对应的图线,则电源的电动势E=
(2)若考虑电压表内阻的影响,方块电阻的测量值
(3)要测出方块电阻的电阻率,先用螺旋测微器测量上下表面间的厚度d。在测微螺杆和测砧相接时,示数如图(a),在夹方块电阻测厚度时示数如图(b),则厚度d=
(4)方块电阻的电阻率表达式为ρ=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76caa19ec164ba47b2ff45eb4a7a1f87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
(1)该同学首先用游标卡尺测得该材料的长度如图甲所示,读数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd1846e964fd60c54888a3c706a97442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://img.xkw.com/dksih/QBM/2021/11/16/2852619018567680/2854711051534336/STEM/c17ec6ba-aafb-4b49-b9f0-8732a9457fe0.png?resizew=517)
(2)现有可供选择的器材如下:
A. 电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/478abdd84506a8ef759e353a238db6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deb4bcbd9cbba7000bf5154da782db51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/365afb8a7c332feeadcba09133b69b2a.png)
B. 电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd842426cfa6e92c5dfbd52d6ada1104.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5cc49fdf0306b7be2c7ae0a3098dea5.png)
C. 电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4388d61dbe462c603456ba1ec9ce7834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8b8c31672cce39bf5f4d474c6466e33.png)
D. 定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/250d02cfa23798a4b6e43c04e4876c3b.png)
E. 滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/365afb8a7c332feeadcba09133b69b2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14ba3ede0350b32e2d94c813d27f2183.png)
F. 滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8b8c31672cce39bf5f4d474c6466e33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6699c896d7394a071917fe3922f3864f.png)
G. 电源
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61588617d22abd00af4ca489bb3a8787.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
H. 开关
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a454a2c91ace8ef50412a6adf91f8086.png)
(3)请根据给出的仪器在虚线框中画出测量电阻的实验电路图,并标出所选器材代号,要求尽量减小误差,获得较多的数据,且电表的示数均能超过量程的三分之一。
![](https://img.xkw.com/dksih/QBM/2021/11/16/2852619018567680/2854711051534336/STEM/e9d0bbc6-60c7-4bc4-b753-01689475f3f2.png?resizew=283)
(4)若用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f1ac49b4139636fb1809fe970b23a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d1a0fd1ad044a9ecfcba672779bd678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
(1)用游标为20分度的游标卡尺测量其长度如图甲,由图甲可知其长度为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d55519bd96aba05e6f1533ddc7bb63fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)
![](https://img.xkw.com/dksih/QBM/2022/2/21/2921232117350400/2921409070907392/STEM/390ad843-4cd9-4996-9fed-789409c8bc6e.png?resizew=446)
(2)该同学想用伏安法更精确地测量待测圆柱体电阻R,现有的器材及其代号和规格如下:
A.待测圆柱体电阻R,长度为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/164932c352061abf01e7e3513b08229d.png)
B.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33e37e5e924d883c3929cfa56afa5bbf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d932ea2f0f29aa1cddc8ef446f2c447.png)
C.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f5f1f7267fdff668b8b40d2f7817b1c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/021888dfdf504a23b64dd2ceec934d09.png)
D.电压表V,量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/30138f72ee11ff33cdbb63d99889083a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c5781d15188260dd0e67a4c6d412cec.png)
E.电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e278c32ede0c61f56cb6c0dc50dc29.png)
F.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e9fd79de5050f5960c9478154c48e830.png)
G.电池E,电动势
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec6ec06bd32883db9b4ea250b06d4313.png)
H.开关S、导线若干
![](https://img.xkw.com/dksih/QBM/2022/2/21/2921232117350400/2921409070907392/STEM/3b41dbda-fd13-4602-bd69-81f438348414.png?resizew=197)
为使实验误差较小,要求测得名组数据进行分析,请在实线框中画出测量的电路图,并标明所用器材的代号。
(3)若该同学用伏安法跟多用电表测量得到的R测量值几乎相等,由此可估算此圆柱体材料的电阻率约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9942091e83e1d59af01f499a0caee212.png)
A.直流电源E(电动势约5V,内阻不计);
B.电压表V1(量程0~5V,内阻r1约10kΩ);
C.电压表V2(量程0~3V,内阻r2=1000Ω)
D.电流表A(量程0~0.6A,内阻r3约1Ω)
E.定值电阻,阻值R0=25Ω
F.滑动变阻器R1(阻值范围0~500Ω,允许通过的最大电流2.0A)
G.滑动变阻器R2(阻值范围0~10Ω,允许通过的最大电流2.0A)
H.开关S一个,导线若干。
![](https://img.xkw.com/dksih/QBM/2020/10/30/2582096558317568/2583432246263808/STEM/e99c0598-641e-4f0a-ac5d-c2f246993f84.png?resizew=327)
①甲同学先进行电流表(量程选0-0.6A)和电压表(量程选0-3V)的读数练习,则其正确的读数分别为
②乙同学设计了如图所示电路,但发现电压表V2的可用范围较小,为了较准确的测量该金属丝电阻Rx,要求两只电表的读数都不小于其量程的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://img.xkw.com/dksih/QBM/2020/10/30/2582096558317568/2583432246263808/STEM/a1d5c0a4-2f3b-4b0d-a9a8-04ebea90eedf.png?resizew=279)
③改进后按电路图连接实物并进行实验,某次测量时,电压表V1的读数为U1,电压表V2的读数为U2,这段电阻丝的长度为L,直径为d,则这段金属丝的电阻率的表达式ρ=
电流表A(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd03792c2bb898cc9effd2dc4036869f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8966188c7bf4735965258d0a2bb1b287.png)
电压表V(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de0c81d3bdfe9dd9fe420c382e8b91c7.png)
可变电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
可变电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
电源E(电动势约为3V,内阻不计)
![](https://img.xkw.com/dksih/QBM/2021/2/2/2649438876745728/2650958445158400/STEM/e9e26bd8-1d00-43f1-a51c-4334cfd1fe47.png?resizew=556)
(1)在实验中,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)
(2)采用伏安法测量金属丝的电阻,为保证电表安全及测量准确、方便,请将实物连线(图乙)补充完整
(3)通过实验测量出金属丝的电阻R,金属丝的长度l,以及金属丝的直径d。则本次实验得到金属丝电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
(4)若实验中电压表出现故障无法使用,实验室另备有以下器材:一只满偏电流为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a52c3601594f484712c7dadc5e6c04a4.png)
①选择可变电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/530f5b63e797195906285c0c03eb9276.png)
②闭合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d43eb0b274e00cbbc4a210da4165042.png)
③保持可变电阻阻值不变,闭合
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/530f5b63e797195906285c0c03eb9276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e2599548b7b123f3c8d0b91aacd5de.png)
④记下电阻箱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e2599548b7b123f3c8d0b91aacd5de.png)
将测出内阻(RG=490Ω)的灵敏电流计与分压电阻串联而改装成3V量程的电压表,分压电阻应选电阻箱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a2c4640b2bee411935f588fc5433c74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e2599548b7b123f3c8d0b91aacd5de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76caa19ec164ba47b2ff45eb4a7a1f87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
(1)该同学首先用游标卡尺测得该材料的长度如图甲所示,读数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd1846e964fd60c54888a3c706a97442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://img.xkw.com/dksih/QBM/2021/11/16/2852619018567680/2854711051534336/STEM/c17ec6ba-aafb-4b49-b9f0-8732a9457fe0.png?resizew=517)
(2)现有可供选择的器材如下:
A. 电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/478abdd84506a8ef759e353a238db6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/deb4bcbd9cbba7000bf5154da782db51.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/365afb8a7c332feeadcba09133b69b2a.png)
B. 电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd842426cfa6e92c5dfbd52d6ada1104.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5cc49fdf0306b7be2c7ae0a3098dea5.png)
C. 电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4388d61dbe462c603456ba1ec9ce7834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8b8c31672cce39bf5f4d474c6466e33.png)
D. 定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/250d02cfa23798a4b6e43c04e4876c3b.png)
E. 滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/365afb8a7c332feeadcba09133b69b2a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14ba3ede0350b32e2d94c813d27f2183.png)
F. 滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a8b8c31672cce39bf5f4d474c6466e33.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6699c896d7394a071917fe3922f3864f.png)
G. 电源
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61588617d22abd00af4ca489bb3a8787.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
H. 开关
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a454a2c91ace8ef50412a6adf91f8086.png)
(3)请根据给出的仪器在虚线框中画出测量电阻的实验电路图,并标出所选器材代号,要求尽量减小误差,获得较多的数据,且电表的示数均能超过量程的三分之一。
![](https://img.xkw.com/dksih/QBM/2021/11/16/2852619018567680/2854711051534336/STEM/e9d0bbc6-60c7-4bc4-b753-01689475f3f2.png?resizew=283)
(4)若用
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f1ac49b4139636fb1809fe970b23a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d1a0fd1ad044a9ecfcba672779bd678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c88d9142df6ba8e43c1a93bd04a1362.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/27/4faffe15-6a38-490a-94b6-54413d424ecc.png?resizew=410)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/27/cdf519f4-ddbd-4fb3-9199-8cc6bde42b18.png?resizew=245)
(1)为满足实验需要,需将量程为15mA、内阻为100Ω的灵敏电流计改装后接入实验电路中的虚线框内,则下列正确的连接方式是
![](https://img.xkw.com/dksih/QBM/editorImg/2023/9/27/942ef9ad-ff10-476e-82ca-2718389226f7.png?resizew=548)
(2)该同学完成电路的连接后,闭合开关S,调节电阻箱的阻值,读取灵敏电流计的示数I,其中灵敏电流计的某一次偏转如图所示,则虚线框两端的电压应为
(3)若不考虑改装后的电表的分流影响,改变电阻箱阻值,测得多组数据,作出如图所示的图像,则电动势E为