![](https://img.xkw.com/dksih/QBM/2017/2/21/1630044580511744/1630044580716544/STEM/6f388a69-f215-47a8-ad35-a18ea7b1a3a6.png?resizew=568)
(1)他们从金属线中抽取一根细金属丝,截取其中的一部分,拉直后用游标卡尺测金属丝的长度,如图2所示,则金属丝长L=
(2)用游标卡尺测金属丝的直径,如图3所示,则金属丝的直径d =
(3)可用的实验器材如下:
①电流表A(量程0~0.6A,内阻约0.5Ω)
②电压表V(量程0~3V,内阻约10 kΩ)
③定值电阻R0(阻值等于5Ω)
④滑动变阻器R1(0~10Ω,额定电流2A)
⑤滑动变阻器R2(0~200Ω,额定电流0.5A)
⑥电源(电动势为4.5V,内阻不计)
![](https://img.xkw.com/dksih/QBM/2017/2/21/1630044580511744/1630044580716544/STEM/4dbc9303-4618-4781-a03c-4f772de99c5f.png?resizew=268)
他们利用上述器材设计了图4的实验电路,为实验调整方便,滑动变阻器应选择
(4)该小组在实验中得到七组电压表示数U和电流表示数I的数据如下:
1 | 2 | 3 | 4 | 5 | 6 | 7 | |
电压U(V) | 0.51 | 0.96 | 2.05 | 2.31 | 2.63 | 2.95 | |
电流I(A) | 0.080 | 0.150 | 0.320 | 0.360 | 0.410 | 0.460 |
![](https://img.xkw.com/dksih/QBM/2017/2/21/1630044580511744/1630044580716544/STEM/8928596c-70c5-44d4-8128-fd59b1b78ff9.png?resizew=513)
![](https://img.xkw.com/dksih/QBM/2017/2/21/1630044580511744/1630044580716544/STEM/c9d194ea-8123-477f-8c09-a503045af344.png?resizew=384)
(5)请在图6的表格中描绘出I-U图线
(6)由图6的图线可知金属丝的电阻Rx=
(7)由上述数据可以计算出金属丝的电阻率ρ=
相似题推荐
A.电源E:电动势约为4.0V,内阻约0.2Ω;
B.电流表A1:量程为0.6A,内阻r1=1Ω;
C.电流表A2:量程为3A,内阻约为0.1Ω
D.定值电阻R1=20Ω;
E.定值电阻R2=5Ω;
F.滑动变阻器R:最大阻值5Ω;
G.开关S一个,导线若干;
H.螺旋测微器。
(1)他用螺旋测微器测量导线的直径d,其中一次测量的示数如图所示,d=
![](https://img.xkw.com/dksih/QBM/2020/5/25/2470081356136448/2470476122251264/STEM/e79bec96-8583-4d5f-bd1b-9ee710983061.png?resizew=358)
![](https://img.xkw.com/dksih/QBM/2020/5/25/2470081356136448/2470476122251264/STEM/27f4aa93-1df0-4efc-afeb-e64999a0a5a6.png?resizew=254)
(2)请根据方框乙内的部分电路,合理选用所给器材,补全测量铜导线电阻的电路,要求在电路图上注明所选元件符号
(3)小明用设计的电路进行实验,获得多组电流表A1和A2的读数I1、I2,描点作图得到如图丙所示的图象。如果把图甲中示数作为铜导线的直径,可以算出铜导线的电阻率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5a8dd9e5a13c22117b770a7f687437e.png)
(4)通过查询相关资料,小明发现铜导线的标准电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5bbb484be4f2f531cf5e719884530176.png)
(1)用螺旋测微器测量金属丝的直径,其中某一次测量结果如图所示,其读数应为
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/26/323e14ed-4adb-49ea-b688-c6f893cb2821.png?resizew=100)
(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(内阻约0.1Ω)、电压表(内阻约3kΩ)、滑动变阻器R(0~20Ω,额定电流2A)、开关、导线若干。某小组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 |
由以上实验数据可知,他们测量Rx是采用图中的
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/26/8c222fb6-a077-4c6c-ac11-4dad61961606.png?resizew=289)
(3)这个小组的同学在坐标纸上建立U-I坐标系,如图丙所示,图中已标出了与测量数据对应的4个坐标点.请在图中标出第2、4、6次测量数据的坐标点,并描绘出U-I图线
![](https://img.xkw.com/dksih/QBM/editorImg/2022/6/26/94cbf7d0-c95d-4b26-aeca-a4f4511362bb.png?resizew=294)
(4)根据以上数据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
(5)任何实验测量都存在误差。本实验所用测量仪器均已校准,下列关于误差的说法中正确的选项是
A.用螺旋测微器测量金属丝直径时,由于读数引起的误差属于系统误差
B.由于电流表和电压表内阻引起的误差属于偶然误差
C.若将电流表和电压表的内阻计算在内,可以减小由测量仪表引起的系统误差
D.用U-I图像处理数据求金属丝电阻可以减小偶然误差
![](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/2023/7/10/4d013748-d6c2-450d-b277-ac8103bfd527.png?resizew=328)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/10/590f61d4-d4a2-4a0a-abe1-819d2e928cc7.png?resizew=356)
(1)实验时,闭合S1,S2置于位置1,改变滑动变阻器滑动触头P的位置,电流表示数有明显变化,电压表没有示数;再将S2置于位置2,情况相同。经检查,电路中所有元件完好,则导线a、b、c、d、e、f、g中出现断路故障的是
(2)修复故障后,用电流表内接法测量Rx的阻值时应该将S2置于位置
(3)用电流表内、外接法得到Rx的电阻率随浓度变化的两条曲线如图乙所示(不计由于通电导致的化学变化)。某次用电流表内接法测得Rx的阻值为2800Ω,Rx的横截面积为20cm²,长度为20cm,则其电阻率为
![](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)
【推荐3】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
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/822ba7fe4ace084802d0d887657ebfe0.png)
![](https://img.xkw.com/dksih/QBM/2018/5/7/1940293920964608/1942067298623488/STEM/9ada8f68-2a3b-4ab8-9c62-5bdcadd3e825.png?resizew=323)
(1)从图中读出金属丝的直径d=
(2) (i)为测金属丝的电阻, 取来两节新的干电池、开关和若干导线及下列器材:
①电压表0~3 V,内阻10 kΩ ②电压表0~15 V,内阻50 kΩ
③电流表0~0.6 A,内阻0.05 Ω ④电流表0~3 A,内阻0.01 Ω
⑤滑动变阻器0~10 Ω ⑥滑动变阻器0~100 Ω
(3)下列说法正确的是
A.电压表应选用器材①
B.电流表应选用器材④
C.实验时通电时间不宜过长
D.d值只需在金属丝中央测量一次即可
![](https://img.xkw.com/dksih/QBM/2018/5/7/1940293920964608/1942067298623488/STEM/28f8535e-57d0-4117-b862-78f43206d526.png?resizew=532)
(ii)实验中某同学想尽可能多的采集一些数据,请为该同学设计一个符合本实验的电路图,并画在下面的虚线框内,然后根据电路图完成实物图的连线
(iii)请用测得的物理量写出该金属电阻率的表达式:ρ=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd21cd9eea4733c4625d2c0626125fc9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/69970f2eb232581ef72b74f5f4a810d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e30f18f463d0e258e591b31e3138f0e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
②乙图中测得电阻丝的直径
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
③该同学将测得的数据(见实验数据表)加以适当的变形,在丙图所示的坐标中描出了五个实验数据点,由此可得待测电阻丝的电阻率约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04bd482c8aa483cd59b4c22636960fe0.png)
(2)丁图是一种电感式微小位移传感器的简化图。a是待测位移的物体,c是空心线圈(接在频率恒定的交流电源上),软铁芯b插在线圈c中并可随物体a在线圈中左右平移。若交流电流计G的示数变小,则待测物体正在
待测金属丝1卷
电源E(电动势4. 5V,内阻r≈0. 5Ω)
电流表A1(量程10mA,内阻RA1=50Ω)
电流表A2(量程30mA,内阻RA2≈30Ω)
滑动变阻器R1(最大阻值为20Ω)
滑动变阻器R2(最大阻值为6000Ω)
定值电阻R3=10Ω
定值电阻R4=400Ω
开关一个、导线若干
![](https://img.xkw.com/dksih/QBM/2020/11/25/2600528791461888/2600730073710592/STEM/3c9e7ed0-64ca-440e-82ea-62edfeb2a40e.png?resizew=113)
(1)螺旋测微器测出金属丝的直径d=
(2)滑动变阻器应选用
(3)为了精确的测量金属丝的电阻率,请在方框中画出实验电路图
![](https://img.xkw.com/dksih/QBM/2020/11/25/2600528791461888/2600730073710592/STEM/e68d62af-6521-4220-9a5e-153b1c834960.png?resizew=240)
(4)连接电路,闭合开关,移动滑动变阻器,并记录下多组电流表A1的示数I1、电流表A2的示数I2,以I1为横坐标,I2为纵坐标,描点作图并测得图象的斜率为k,则金属丝的电阻率可以表示为