A.螺旋测微器、刻度尺
B.直流电源E(电动势为3V)
C. 电流表A(量程100mA,内阻为1.2Ω)
D.电压表V(量程3.0V,内阻未知)
E.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
F.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
G. 电阻箱R3(0~99.9Ω)
H.开关一只,导线若干
他们进行了以下操作
(1)用螺旋测微器测量金属丝的直径d如图1所示,该金属丝的直径为
![](https://img.xkw.com/dksih/QBM/editorImg/2023/4/27/6ce8bae7-e6eb-483c-b0c1-d857b3ad3efd.png?resizew=530)
(2)实验时为避免烧毁电流表A,他们将电流表A和电阻箱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a2c4640b2bee411935f588fc5433c74.png)
(3)为方便操作,滑动变阻器应选择
(4)改变接入电路中的金属丝长度l并用刻度尺测量,调节滑动变阻器的滑片至合适的位置,使电压表的示数恒为2.4V,读出对应电流表示数I,将l、I转换为国际单位制后作出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e96fe4b12c745969608494884260876e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/367e788c32187ae2cc97aaa24da1d40d.png)
![](https://img.xkw.com/dksih/QBM/2023/3/31/3206601328082944/3207307097268224/STEM/42463eaafff546ceba0f392421dcefa3.png?resizew=554)
(1)用游标卡尺测量长度L,如图甲所示,L为
(2)由螺旋测微器测量直径d,如图乙可知,d为
(3)新材料制成的圆柱体阻值大约为5Ω,用伏安法测电阻时,由于电压表、电流表内阻有影响,为了减小系统误差,则选择如图丙
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20321c69d95af5e5a3adc104975a9a6a.png)
)。图甲为该组同学用绝缘材料制成的长度
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b46f68d57dfb24626ed4ec2c3b5ac388.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/29/915b8ea1-679b-435d-a515-a6e27f5a1ccb.png?resizew=550)
(1)装入污水样品前,需测量圆筒形盛水容器的内径,应使用图乙中游标卡尺的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
(2)将污水样品装满圆筒形盛水容器后,用电阻可忽略、带有接线柱的金属圆片将两端密封,并用欧姆表测出该样品的电阻为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d02e8ca16e7f5da79d5dc4e4cc183a23.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
A.电源E(电动势约
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40d48358392978b7ee4d6d803533a9d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66de503c8055c43644b847eba74b50f.png)
B.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/74e07a0e678dd1c3218d52860fa4d06f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a9616d2a37245f6d4415633e947290d8.png)
C.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9e65b2e896a5c2371ef4d17d58d2709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20786232cf70d0040233ac324d43e462.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2b3e95410f3b4fcb0cba425b521d1f67.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ee5b7e91d647021b85a223fb0483b05a.png)
D.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/90b2eb2730da730b1cfb9ae5dcfba2f3.png)
E.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/edc43f644f43444a05c0816cf9768c87.png)
F.开关S,导线若干
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/29/6ad9ae8d-9e9f-4686-af25-13b8bb15088d.png?resizew=180)
(3)经正确操作,读出电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9e65b2e896a5c2371ef4d17d58d2709.png)
![](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/857dbf14258d4b32dfe4e2cc799f245d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9942091e83e1d59af01f499a0caee212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86ebba6ed1add0fe647c0226614b9290.png)
(4)若装入的污水样品中有气泡,这将会使测得的污水样品的电阻率
4 . 小李同学在“测定金属的电阻率”实验中。
(1)因电表内阻未知,用如图甲所示的电路来判定电流表该内接还是外接。正确连线后,合上开关S,将滑动变阻器的滑片P移至合适位置。单刀双掷开关K掷到1,电压表的读数U1=1.65V,电流表的示数如图乙所示;将K掷到2,电压表和电流表的读数分别为U2=1.75V,I1=0.33A.由此可知应采用电流表
(2)完成上述实验后,小李同学进一步尝试用其他方法进行实验:
此时所用测量仪器均已校准。待测金属丝接入电路部分的平均长度为50.00cm。
①用螺旋测微器测量金属丝的直径如丙图所示。
②用伏安法测金属丝的电阻Rx,实验所用器材为:电池组(电动势3V,内阻约1Ω)、电流表、电压表、滑动变阻器R(0~20Ω,额定电流2A)、开关、导线若干。小李同学利用以上器材正确连接好电路,进行实验测量,记录数据如下:
次数 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
U/V | 0.10 | 0.30 | 0.70 | 1.00 | 1.50 | 1.70 | 2.30 |
I/A | 0.020 | 0.060 | 0.160 | 0.220 | 0.340 | 0.460 | 0.520 |
图丁是测量Rx的实验器材实物图,图中已连接了部分导线,滑动变阻器的滑片P置于变阻器的一端。请根据上述表格的实验数据,补充完成图丁中实物间的连线
③小李同学在坐标纸上建立U、I坐标系。如图戊所示,图中已标出了与测量数据对应的坐标点。描绘出UI图线。由图线得到金属丝的阻值Rx可以估算出金属丝电阻率约为
A.1×10-2Ω·m B.1×10-3Ω·m C.1×10-6Ω·m D.1×10-8Ω·m
A.电压表V1(量程0~3 V,内阻约为15 kΩ);
B.电压表V2(量程0~15 V,内阻约为75 kΩ);
C.电流表A1(量程0~3 A,内阻约为0.2 Ω);
D.电流表A2(量程0~0.6 A,内阻约为1 Ω);
E.滑动变阻器R1(0~10 Ω,0.6 A);
F.滑动变阻器R2(0~2 000 Ω,0.1 A);
G.电池组E(电动势为3 V);
H.开关S,导线若干。
(1)为减小实验误差,应选用的实验器材有
(2)为减小实验误差,应选用如图中
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/10/5b565a57-4dd2-4c4a-bff4-a4ad9f5504c3.png?resizew=487)
(3)若用毫米刻度尺测得金属丝长度为60.00 cm,用螺旋测微器测得金属丝的直径及两电表的示数如图丁所示,则金属丝的直径为
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/10/fbea23e4-9c77-4b41-9fd1-018263c71d83.png?resizew=388)
(4)金属丝的电阻率为
(1)该实验小组用刻度尺测量其长度L、螺旋测微器测量其直径D,某次直径测量结果如图所示:D=
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/26/e2d7817a-e560-4196-899d-a43fdeea698e.png?resizew=194)
(2)实验使用的滑动变阻器的阻值为0~20Ω,请将如图实际测量电路补充完整
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/26/e094ef6f-e97c-4754-b122-3308f4d1a3e1.png?resizew=259)
(3)闭合开关前,滑动变阻器的滑片应置于
(4)某次实验时,电压表的示数为U,电流表的示数为I,用实验测量的物理量L、D、U、I表示电阻率,则表达式为ρ=
①首先通过螺旋测微器测量铜棒直径,通过游标卡尺测铜棒的长度,测量结果如图甲、乙所示,则铜棒直径d
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/16/5f307141-20d3-4201-8117-a45747bd1468.png?resizew=426)
②为了精密测量该金属丝的电阻率,某实验小组先使用多用电表粗测其电阻约为6,然后进行较准确测量,除待测金属丝外,实验室还备有的实验器材如下:
A.电压表V1(量程3V,内阻约为15k) B.电压表V2(量程15V,内阻约为75k)
C.电流表A1(量程3A,内阻约为0.2) D.电流表A2(量程600mA,内阻约为1)
E.滑动变阻器R1(0-5Ω,0.6A) F.输出电压为3V的直流稳压电源
G.电阻箱 H.开关S,导线若干
为尽量减小实验误差,电压表选
③如果金属丝直径为D,长度为L,所测电压为U,电流为I,写出计算电阻率的表达式
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/12/4b8393ae-2906-4714-a61c-a2979d020203.png?resizew=551)
(1)用螺旋测微器测量金属丝的直径,其中某次测量结果如图甲所示,则金属丝的直径d=
(2)在用欧姆表“×10”挡粗测金属丝电阻值时,在规范操作下,发现欧姆表指针偏转角较小,因此需重新选择
(3)改用如图丙所示电路测量该金属丝的阻值。在开关闭合前滑动变阻器的滑动端应置于图中的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/12/e2640119-0430-4fb5-94e7-72ce9cf6361d.png?resizew=177)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/4/a85af2df-0e2e-4991-ab51-e13e3eb58c8c.png?resizew=458)
(1)先用米尺和螺旋测微器分别准确测出金属丝的长度L和直径d;
(2)接着该同学用如图所示的电路测量金属丝的电阻,图中
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72dab914607bdc41d500d3f3b23d6129.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
①按照实验原理线路图甲,将图乙中实物完整连线
②将滑动变阻器滑动触头置于
③改变滑动变阻器滑动端的位置,记下此时电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9e65b2e896a5c2371ef4d17d58d2709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f1ac49b4139636fb1809fe970b23a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d1a0fd1ad044a9ecfcba672779bd678.png)
④重复步骤③,得到如下数据:
1 | 2 | 3 | 4 | 5 | |
0.10 | 0.21 | 0.30 | 0.42 | 0.51 | |
0.51 | 1.02 | 1.49 | 2.03 | 2.52 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/857dbf14258d4b32dfe4e2cc799f245d.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/4/c47867cb-7406-4498-8a7c-1863e9ae2d01.png?resizew=363)
⑤根据图线求得金属丝电阻值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67c1313842b62428737610b14806d883.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)
(3)最后由以上测得的物理量,可以求出该金属丝的电阻率,计算电阻率的公式为:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
(1)用螺旋测微器测量器件的直径,示数如图甲,其直径
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/ebc47b93-d128-489c-9655-fd06a708c80e.png?resizew=196)
(2)先用欧姆表“×100”挡粗测该器件的电阻,指针位置如图乙,为更准确地粗测其电阻,从下列步骤中选出再次粗测必要的操作并排序
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/2abf6693-2843-4fe1-88be-0d5d13c654c2.png?resizew=335)
①将选择开关旋转到欧姆挡“×1k”位置
②将选择开关旋转到欧姆挡“×10”位置
③将两表笔与器件相接完成测量
④将两表笔短接,调节欧姆调零旋钮使指针指向“0Ω”
⑤把选择开关旋转到交流电压最高档
⑥用螺丝刀调节指针定位螺丝,使指针指0
(3)粗测器件阻值约为180Ω,为精确测量器件的电阻Rx在额定电压时的阻值,要求测量时电表的读数不小于其量程的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/fe30a997-cf34-4563-9467-03680f1c2b55.png?resizew=185)
A.电流表A1(量程为60mA,内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/81599580afcea9e8ec121faa69263f38.png)
B.电流表A2(量程为5mA,内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1abbdaf69dcea59ae6b507d3a421aba.png)
C.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/544a2218d1b67d3b5b278d2cb6f14fa9.png)
D.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/063d80adf727ca6de126d6f7d0f878f5.png)
E.滑动变阻器R(0~20Ω)
F.电压表V(量程为3V,内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5926500660ed2e0936b13713537dca14.png)
G.蓄电池E(电动势为4V,内阻很小)
H.开关S,导线若干
(4)实验中根据两电表读数作出如图所示的图线(坐标均为国际单位),已知图线的斜率为k,则所测导电玻璃的电阻Rx=
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/1/6a76f3e1-66e0-44ae-adf2-000338a70539.png?resizew=163)
(5)研究实验误差时发现实验所用定值电阻的阻值偏大,则电阻率的测量值将