(1)已知金属丝长度为L,利用螺旋测微器测金属丝直径d,如图甲所示,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://img.xkw.com/dksih/QBM/2021/1/5/2629680837672960/2633275144200192/STEM/819fdb06-434c-4cf8-a10c-89d27faf8fcd.png?resizew=308)
(2)学习小组的A同学先用多用电表测得该金属丝的电阻大约为50Ω,实验室提供了如下器材:
电源E:电动势约为5.0V,内阻可忽略不计
电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddaaf2243a58091bfbf25f3d8180c896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1aeaf14426572aecebf988c30c2eaf9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85384db95751991cb57636811729b253.png)
电流表A:量程为0~0.6A,内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f2cb48c0a69b8c420c0b64b2bfa1ef7.png)
定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
开关S一个,导线若干
为了进一步准确测量金属丝的电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddaaf2243a58091bfbf25f3d8180c896.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a83f944fef003a277a0bafb2d447c69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/52b4bfdcc569852d861fd6a15ec42c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a83f944fef003a277a0bafb2d447c69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/756dfc20875434b5dc29fe6e24219474.png)
(3)B同学发现电流表量程太大,实验中读数误差会比较大,又重新选择了实验器材,测量中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://staticzujuan.xkw.com/quesimg/Upload/formula/1aeaf14426572aecebf988c30c2eaf9b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc0548b4e1c25f4a61583681e2a4ca61.png)
![](https://img.xkw.com/dksih/QBM/2021/1/5/2629680837672960/2633275144200192/STEM/2b504045-0cf4-4db7-ba16-c7c7dc3444e3.png?resizew=352)
![](https://img.xkw.com/dksih/QBM/2021/6/25/2750549433761792/2751550618165248/STEM/e73b8913-53ae-4ac2-a8b2-8fcbf79dd1f9.png?resizew=379)
(1)利用螺旋测微器测金属丝直径d,如图1所示,则d=
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
(2)测量金属丝电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d1db616d129873d3f95a87ac770dac84.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4833b05f941a2d8abe2e04f3bff8aec5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/77a6041c88c8701ce1068b611f27aa4a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6c59076e80b15755ef630fd5f40d1f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e3e0a6f3b59a4cca5721ec634408d197.png)
A.电流表(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/947e97835206d91d18ea14b68ed1b031.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0754c1fdc83f61abb0ae9dab54e8a98f.png)
B.电流表(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd03792c2bb898cc9effd2dc4036869f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0055db6cc2453dd4e5ce61f7dc1d4021.png)
C.电压表(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/de0c81d3bdfe9dd9fe420c382e8b91c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/951f5dfc2ee88b950c0a4322d9236ce4.png)
D.滑动变阻器(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9b65177eb9c7ace11b185dec72574949.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6699c896d7394a071917fe3922f3864f.png)
E.滑动变阻器(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b67a2c8d0df307f95b51867d67b01c4b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d73c327d0f1396ddc8f8a4c1662cd626.png)
(1)为减小误差,且便于操作,在实验中电流表应选
(2)如图所示,是测量该电阻丝电阻的实验器材实物图,图中已连接了部分导线,还有两根导线没有连接,请补充完成
![](https://img.xkw.com/dksih/QBM/2020/5/28/2472463115231232/2472648167710720/STEM/3a276064-4439-4714-960c-9c67404e67d6.png?resizew=268)
(3)在开关闭合前,滑动变阻器的滑片应当调到最
(4)若不计实验中的偶然误差,则下列说法正确的是
A.测量值偏大,产生系统误差的主要原因是电流表分压
B.测量值偏小,产生系统误差的主要原因是电压表分流
C.若已知电压表的内阻,可计算出待测电阻的真实值
D.若已知电流表的内阻,可计算出待测电阻的真实值
![](https://img.xkw.com/dksih/QBM/2020/4/27/2450549433409536/2450776447647745/STEM/59a146e5-fabf-4f90-b115-88e9451c12c3.png?resizew=172)
(1)先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
(2)现有电源(电动势E为 3.0 V,内阻不计)、开关和导线若干,以及下列器材:
A.电流表(量程 0~0.6 A,内阻约 0.125 Ω)
B.电压表(量程 0~3 V,内阻约 3 kΩ)
C.滑动变阻器(0~20 Ω,额定电流 2A)
![](https://img.xkw.com/dksih/QBM/2020/4/27/2450549433409536/2450776447647745/STEM/20e1802a-675c-4bda-8814-427491981765.png?resizew=347)
![](https://img.xkw.com/dksih/QBM/2020/4/27/2450549433409536/2450776447647745/STEM/ed0ec5fd-4655-4a56-bd5c-a48bb0ea2b89.png?resizew=314)
①图甲是测量该电阻丝实验器材的实物图,请补充完成电路。并在图中标出:开关闭合前,滑动变阻器的滑片的位置;
②若不计实验中的偶然误差,则下列说法正确的是
A.测量值偏大,产生系统误差的主要原因是电流表分压
B.测量值偏小,产生系统误差的主要原因是电压表分流
C.若已知电压表的内阻,可计算出待测电阻的真实值
D.若已知电流表的内阻,可计算出待测电阻的真实值
③小鹏同学仍用上述电源,也设计了一个实验,电路如图乙所示,R 为保护电阻,已测出电阻丝的横截面积为S,用一个带有接线柱的小金属夹沿电阻丝滑动,可改变接入电路中电阻丝的长度 L,实验中记录了几组不同长度 L 对应的电流 I。他准备利用图像法处理数据来计算该电阻丝的电阻率。
请分析说明小鹏同学应该做出怎样的线性函数图像,并定性画出该图像;请指出在本实验中电流表的内阻对该电阻丝电阻率的测量结果有无影响。
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec93c110d3f0f8ff7de893c11cd29bfd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85b0e51d98e0e163444c5b397eca276a.png)
A.电流表(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/947e97835206d91d18ea14b68ed1b031.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cc3bd650a2d1007d675519b498aee91f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/64eea08dbac8bc0aa845c8541672a9b1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c029849e4b7013959bf29c9384d5bb40.png)
C.电压表(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/67f348292d1ed41299d0e260fc951388.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f281e85fffd9edc43576e43fddaf501a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1ee03037e03c496bb742abfc67422c95.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04fa051e5a7b175d0d95b5e84558dd0e.png)
E.滑动变阻器(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d6b662748aec80419166ab6b96b5f28.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d73c327d0f1396ddc8f8a4c1662cd626.png)
(1)为减小误差,且便于操作,在实验中电流表应选
(2)如图所示,是测量该电阻丝电阻的实验器材实物图,图中已连接了部分导线,还有两根导线没有连接,请用笔替代导线,补充完成
![](https://img.xkw.com/dksih/QBM/2020/7/1/2496572455051264/2496705149665280/STEM/ebabb461-d927-4021-b1fa-c20c2e449838.png?resizew=234)
(3)在开关闭合前,滑动变阻器的滑片应当调到最
(4)若不计实验中的偶然误差,则下列说法正确的是
A.测量值偏大,产生系统误差的主要原因是电流表分压
B.测量值偏小,产生系统误差的主要原因是电压表分流
C.若已知电流表的内阻,可计算出待测电阻的真实值
![](https://img.xkw.com/dksih/QBM/2019/12/2/2346445367500800/2346509132488704/STEM/c6a94301-23d8-4265-bb64-d20dccc636b5.png?resizew=297)
![](https://img.xkw.com/dksih/QBM/2019/12/2/2346445367500800/2346509132488704/STEM/a464b1ac-d6bf-4f97-9944-01f76fb0b2f8.png?resizew=117)
(1)某学生进行了如下操作:
①利用螺旋测微器测金属丝直径d,如图1所示,则d=
②测量金属丝电阻Rx的电路图如图2所示,闭合开关S,先后将电压表右侧接线端P接a、b点时,电压表和电流表示数如表1所示.该学生认真观察到两次测量中,电流表的读数几乎未变,发生这种现象的原因是
表1
U(V) | I(A) | |
接线端P接a | 1.84 | 0.15 |
接线端P接b | 2.40 | 0.15 |
表2
U(V) | I(A) | |
接线端P接a | 2.56 | 0.22 |
接线端P接b | 3.00 | 0.20 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a6bb65878785532d817f8fd11a9ef3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad53b547e11f3e4719a70a4b9564cc8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/763d54584c0b1e0bc74ccd5756624ff7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3268ee21400e819481400197ea8dc736.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d757a8853133814c9a9753443c1cf82.png)
(2)用螺旋测微器测量镀膜后的陶瓷管直径D,示数如图丙所示,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
(3)闭合开关后,移动滑片,测出多组电表示数的U,I值,并画出
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e43cca5751eff3d24b64cb51006d6d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3ef4881bd7c5860178dbdbc7bba6e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
(5)金属膜电阻的电阻率测量值偏大,试写出产生误差的主要原因
8 . 在做测定金属的电阻率的实验中,若待测电阻丝的电阻约为5Ω,要求测量结果尽量准确,备有以下器材:
A.电池组(3V,内阻r=1Ω)
B.电流表(0~3A,内阻约0.0125Ω)
C.电流表(0~0.6A,内阻约0.125Ω)
D.电压表(0~3V,内阻约4kΩ)
E.电压表(0~15V,内阻约15kΩ)
F.滑动变阻器(0~20Ω,允许最大电流1A)
G.滑动变阻器(0~2000Ω,允许最大电流0.3A)
H.开关、导线
(1)上述器材中应选用的是
(2)在本实验中,某同学用游标卡尺和螺旋测微器测该电阻丝的长度L和直径d。
(3)实验电路应采用如图所示哪个
(4)接通开关,改变滑动变阻器滑片P的位置。并记录对应的电流表示数I,电压表示数U。
(5)本实验所用电路,产生误差的主要原因是
A.电流表测量值小于流经Rx的电流值
B.电流表测量值大于流经Rx的电流值
C.电压表测量值小于Rx两端的电压值
D.电压表测量值大于Rx两端的电压值
(6)用实验过程中测量的物理量对应的字母表示电阻率,则该圆柱复合材料电阻率的表达式为=
(2)用欧姆表接薄膜M、N两端,测得薄膜电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18357853560ede5d670851756f403ca3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
A.电源E(电动势为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910928687da37388715dd531939fbfed.png)
B.电压表V(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3eb4528690a27996e239c56d16d5111f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ad7efc8b1469128dacfe0247c8818595.png)
C.电流表A1(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b5c929172bbfc21741fa7ef1f53b7bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9db144c76e36b0c4d950698b2bbc39f9.png)
D.电流表A2(量程
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e11d69118d4c8965597a9cca909eeac0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d34a0b9cef46caaa59e64fa49cdbda4.png)
E.滑动变阻器R(最大阻值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78aa8e890d2ac882e0fe79598811777a.png)
F.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c8dc2b5cdc9c47ac6e875c496c7b886.png)
G.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5f8317fe658aab4927895666dc7dce4.png)
H.开关一个,导线若干
(3)其中,电流表应选
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
(4)根据以上要求,将图(b)所示的器材符号连线,组成测量电路图
(5)已知该薄膜的电阻率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
(6)实验后发现,所测薄膜的厚度偏大,其原因可能是
①电压表内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/def79c5936390efaee606aeb6e850c99.png)
②电压表内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/def79c5936390efaee606aeb6e850c99.png)
③选用的定值电阻标定值比实际值偏大
④选用的定值电阻标定值比实际值偏小
(1)正确操作用游标卡尺测得金属丝的长度L为
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/23/3fcb6a15-84ab-4879-ac6f-d966f0d6c2b1.png?resizew=314)
(2)估算被测电阻丝的阻值50Ω,已知实验中所用的滑动变阻器阻值范围为0~10Ω,电流表内阻约为几欧,电压表内阻约为20kΩ,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,内阻很小忽略不计,则以下电路图中
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/23/20bcb24f-a1be-48fa-91f6-fa8c8e87a551.png?resizew=557)
(3)请根据第(2)问中选择的电路图,补充完成图丙中实物间的连线,并使闭合开关的瞬间,电压表或电流表不至于被烧坏
![](https://img.xkw.com/dksih/QBM/editorImg/2023/6/23/59fdd62f-cf90-44cb-a6e5-6289c384885d.png?resizew=206)
(4)本实验中金属丝的电阻率为
(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.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,可以消除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