(1)如下图所示:图中用螺旋测微器测量金属材料的直径为
![](https://img.xkw.com/dksih/QBM/2021/1/16/2637556056924160/2638804138065920/STEM/5dd7ce2f-9625-4021-bd1a-31cd964fa5e0.png?resizew=161)
(2)实验中,要求电压从零开始调节,除开关、导线外,还有如下器材:
R金属丝(电阻约为十几欧姆)
E直流电源6~8V
A1电流表(量程0.6A,内阻约1Ω)
A2电流表(量程3A,内阻约0.2Ω)
V1电压表(量程15V,内阻约60kΩ)
V2电压表(量程5V,内阻约20kΩ)
R1滑动变阻器(1kΩ,0.5A)
R2滑动变阻器(0~10Ω,2A)
①实验所用到的电流表应选
②在虚线框内画出最合理的实验原理图,并标出相应的字母符号。
![](https://img.xkw.com/dksih/QBM/2021/1/16/2637556056924160/2638804138065920/STEM/70fbc1bc-f584-42f5-bad4-4efb21bd150c.png?resizew=154)
(3)测量圆柱形金属材料的电阻率的表达式
相似题推荐
【推荐1】某实验小组想测量一段粗细均匀合金材料的电阻率,用多用电表测得该合金材料的电阻R2大约为5kΩ,除被测电阻外,还有如下实验仪器:
A.电源(电动势6V, 内阻约为2Ω)
B.电流表A1(量程0~1mA, 内阻约为15Ω)
C.电流表A2(量程0~300mA,内阻约为100Ω)
D.电压表V (量程0 ~ 5V, 内阻约5kΩ)
E.滑动变阻器R₁(0~20Ω,额定电流2A)
F.滑动变阻器R₂(0~5Ω,额定电流0.2A)
G.开关、导线若干
实验步骤如下:
(1)上述器材中,应该选用的电流表是
(2)为减小误差,应选采用下列实验电路图进行实验,较合理的是
(3)用螺旋测微器测合金材料的直径D,示数如图甲所示,其直径D为
(4)若电流表示数为I、 电压表示数为U,则合金材料的电阻率的表达式为
Ⅰ.先用多用电表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/39e163e962126ef03763fa3a25748220.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
![](https://img.xkw.com/dksih/QBM/2021/10/9/2825796784087040/2826527931047936/STEM/a2c3666d-82b6-4f45-ae24-7269e9d7dded.png?resizew=543)
Ⅱ
![](https://img.xkw.com/dksih/QBM/2021/10/9/2825796784087040/2826527931047936/STEM/92404c0aa02d47858a2e7c2f3f1c6e74.png?resizew=3)
A.电压表V1量程3V,内阻约为15
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a08563f19abb0273da6df98ab24f214.png)
B.电压表V2量程15V,内阻约为75
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a08563f19abb0273da6df98ab24f214.png)
C.电流表A1量程3A,内阻约为0.2
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
D.电流表A2量程600mA,内阻约为1
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
E.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5c2329cbebfc551d07a99d0d853d317.png)
F.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f26bfa636391b1654e63293dc32c173.png)
G.输出电压为3V的直流稳压电源E
H.电阻箱
I.开关S,导线若干
为了测多组实验数据,则上述器材中应选用的实验器材有(填代号)
![](https://img.xkw.com/dksih/QBM/2016/1/15/1575809240023040/1575809240350720/STEM/ca88c7918c8b4dd794c40aad69d58ab1.png?resizew=494)
(2)已知实验中所用的滑动变阻器阻值范围为0~10Ω,电流表内阻约几欧,电压表内阻约20kΩ,待测电阻大约几欧,电源为干电池(不宜在长时间、大功率状况下使用),电动势E=4.5V,内阻很小,则图乙电路图中
![](https://img.xkw.com/dksih/QBM/editorImg/2022/10/2/1601c9b6-c9f8-4b97-a173-efcb1a5168e4.png?resizew=550)
(3)若已知实验所用的电流表内阻的准确值RA是已知的,那么准确测量金属丝电阻Rr的最佳电路应是图乙中的
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/655b1145-4f3f-429a-98e6-07ad94c998ef.png?resizew=95)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/97ae15a3-fc6f-4c64-b284-f71214ac5b72.png?resizew=194)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/a84ed275-b283-4db4-831a-23ec83e5cea8.png?resizew=238)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/13/2026de92-4b85-494f-8c67-37fc5c26e1a3.png?resizew=128)
(1)用螺旋测微器测量金属丝的直径时,测量结果如图甲所示,直径的读数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
(2)某同学设计了图乙所示的实验电路图,请在图丙中用笔画线代替导线补充完整实物连线
(3)将图乙中滑动变阻器的滑动触头滑到最
![](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)
![](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)
(4)根据多组测量得到的实验数据描绘出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b5d5f2b925044fa13e4bd59496a4625.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/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/2/c9f754fe-d434-4efe-973e-ea488d18d37c.png?resizew=113)
(1)用螺旋测微器测量电热丝的直径,其中某次测量结果如图甲所示,则电热丝的直径
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
(2)用毫米刻度尺测得电热丝的长度L。
(3)用多用电表欧姆挡测得电热丝的电阻约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d6e278c32ede0c61f56cb6c0dc50dc29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/486f30b44d1e6ffde2b0682808ca010b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78c5ae75672f958823c1fde935be7bea.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e064957bcb1884fc847ca9bd4d3ed91.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
A.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/2/3855bdad-3082-465d-b9a8-12509284df81.png?resizew=112)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/2/42e2ff5e-9356-4973-b8dd-365ac511d598.png?resizew=110)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/2/e8242082-180d-4b51-8fb2-38b99296d539.png?resizew=103)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/2/6595c15e-58a0-446f-b460-30e8c4209131.png?resizew=124)
(4)选择合适电路,进行正确操作,测得电流表示数为I,电压表示数为U,则电热丝的电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
电池组(电动势3 V,内阻约1 Ω)
电流表(内阻约0.1 Ω)
电压表(内阻约3 kΩ)
滑动变阻器R(0~50 Ω,额定电流2 A)
开关、导线若干
请完成下列问题:
(1)用螺旋测微器测量金属丝的直径,为防止读数时测微螺杆发生转动,读数前应先旋紧如图甲所示的部件
![](https://img.xkw.com/dksih/QBM/2021/2/22/2663639335067648/2663772867534848/STEM/219d6e20-e715-43de-b0ed-aadf7fa745e6.png?resizew=288)
![](https://img.xkw.com/dksih/QBM/2021/2/22/2663639335067648/2663772867534848/STEM/2c5eb792-9f27-4816-bacf-67e2ca3db861.png?resizew=539)
(2)某小组同学利用以上器材进行实验,请根据原理图乙完成实物图丙中的连线,并使在闭合开关的瞬间,电压表或电流表不至于被烧坏
次数 | 1 | 2 | 3 | 4 | 5 | 6 |
U/V | 0.30 | 0.70 | 1.00 | 1.50 | 1.70 | 2.30 |
I/A | 0.066 | 0.160 | 0.220 | 0.340 | 0.460 | 0.520 |
![](https://img.xkw.com/dksih/QBM/2021/2/22/2663639335067648/2663772867534848/STEM/9f375292-4505-4fa3-b435-29da4cbd934d.png?resizew=264)
(3)这个小组的同学在坐标纸上建立U、I坐标系,如图丁所示,图中已标出了与测量数据对应的6个坐标点。请根据标出的坐标点,请描绘出U-I图线
(4)若实验过程中发现,无论如何调节滑动变阻器,电压表示数不发生变化,则发生故障的可能原因是
(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有
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.测量金属丝的直径时,要在不同位置多次测量,是为了消除偶然误差
C.由电流表和电压表的内阻引起的误差属于偶然误差
D.用U-I图像处理数据求金属丝电阻可以减小偶然误差