1 . 在实验室中测量一金属丝的电阻率:
(1)先用多用电表×10Ω挡粗测其电阻发现多用表指针偏角偏大,为进一步较精确测量选用合适的倍率重新欧姆调零后,测量时指针位置如图1所示,其电阻为
(2)为了减小实验误差,需进一步测其电阻,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1.5kΩ)
B.电压表V2(量程15V,内阻约为75kΩ)
C.电流表A1(量程3A,内阻约为0.2Ω)
D.电流表A2(量程0.6A,内阻约为1Ω)
E.滑动变阻器R1(0~5Ω,允许通过的最大电流1.0A)
F.滑动变阻器R2(0~2000Ω,允许通过的最大电流1.0A)
G.输出电压为2.5V的直流稳压电源E
H.开关S,导线若干
①为了测多组实验数据,则上述器材中电流表应选用
②根据所选仪器设计好电路,画在虚线框中。
(3)关于本实验的误差,下列说法正确的是
A.用螺旋测微器、游标卡尺测量时,由于读数引起的误差属于系统误差
B.将读出的几组电表示数取平均值代入公式计算电阻可以减小误差
C.为了减小读数误差,电表读数时应多估读几位
D.利用U-I图像处理数据求出金属丝电阻可以减小偶然误差
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
电流表A:量程1
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58b5bd7cf13ef88690281ce09f1d3471.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1417896ee86bfeea79c5439baa8445c7.png)
电池组E:电动势6V,内阻不计;
电压表V:量程3V,内阻约为5
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2d42df4aad2c3637f07e0125a88ffa9.png)
定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b70044429950f6511ce6b2d2d99eb5c.png)
定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e8cf9149fc466a92f2743d82b7a1edf.png)
滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
开关S、导线若干。
(1)某实验小组选用欧姆表“×1”挡进行粗测,正确操作后,表盘指针如图所示,则该电阻的测量值为
![](https://img.xkw.com/dksih/QBM/2021/4/22/2705280930070528/2705481545850880/STEM/b15ad988-c0a1-4046-a5fc-cb2e57c7c70d.png?resizew=766)
(2)实验要求尽可能多的测量数据,根据所提供的器材在方框内画出电路图,要求在电路图中标出所选器材的符号。
(3)用螺旋测微器测量该金属丝的直径,结果如图所示,则该金属丝的直径d为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
(4)连接实物图,闭合开关调节滑动变阻器得到多组
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e43cca5751eff3d24b64cb51006d6d7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ebda2a68ab386360b9bdf8223d9a032.png)
U/V | 0.60 | 1.02 | 1.54 | 2.05 | 2.55 |
I/ | 0.20 | 0.34 | 0.51 | 0.68 | 0.85 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
A.压敏电阻,无压力时阻值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c75039c1b0c9d742ba3d22c5985de2ed.png)
B.直流电源,电动势
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3088c2099211295de775ee33dd1d03fc.png)
C.电流表A,量程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e11d69118d4c8965597a9cca909eeac0.png)
D.电压表V,量程为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a6bb65878785532d817f8fd11a9ef3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/951f5dfc2ee88b950c0a4322d9236ce4.png)
E.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f7aaf0453025256019780d3316cc939.png)
F.滑动变阻器R,最大电阻值约
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c1487858ca25b9de96d3aa12232c0c0a.png)
G.开关S与导线若干
![](https://img.xkw.com/dksih/QBM/2021/3/9/2674035147538432/2674205372686336/STEM/2b5be17f287e4384855a10137be49c44.png?resizew=539)
(1)甲同学设计了图1实验电路原理图,请在图2将实物连线图补充完整
(2)某次压力测试,在电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
(3)改变F的大小、测得不同的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd707b69a11f8de5566f23c1a2a9ff5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94dc39f6b9bee6185a532124b242c5b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
(4)按图1实验电路进行实验,调节滑动变阻器使电压表保持满偏,在电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bff82f1058ab5b7e2740c9cce40109d4.png)
水(25℃)的电阻率/(![]() | 500 | 50 | 5 |
溶解的固体含量/(mg·L-1) | 0.010 | 0.100 | 1.00 |
水(25℃)的电阻率/(![]() | 0.5 | 0.1 | 0.01 |
溶解的固体含量/(mg·L-1) | 10 | 50 | 500 |
小聪将水样通过阀门K注满一绝缘性能良好的圆柱形塑料容器,容器两端用固定的圆形金属电极密封(如图甲所示),再接在如图乙所示的电路(电源电动势为E,电流表的量程为Ig,测量前将红、黑表笔短接,使电流表满偏)的红、黑表笔之间,读出此时电流表的示数。小聪根据不同水样对应的电流值,得到不同水样对应的电阻率,将电阻率对应的固体含量值标在电流表表盘对应的刻度线上,这样就将电流表改装成了一个简易的固体含量计。
![](https://img.xkw.com/dksih/QBM/2022/1/17/2896502873366528/2896662924271616/STEM/092f26bb-b0ee-43cc-af24-876346637fc8.png?resizew=399)
(1)在如图乙所示的电路中,
(2)此固体含量计上较小的固体含量值对应电流表的电流值
(3)某次测量时,电流表的指针恰好半偏,测得该容器两电极间的长度为L,水柱的内径为d,则水样的电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8991b8ef8d1dc326116d0b444053bac9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d5b124139673bdd764c3a80cb52bd6a8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ddc8fe85313a46a3c3db1e0ee442f505.png)
(4)若此固体含量计使用一段时间后,所用电源的电动势不变、内阻变大,则测量前需将滑动变阻器R接入电路的电阻适当调
A.待测金属丝(电阻约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d757a8853133814c9a9753443c1cf82.png)
B.毫米刻度尺
C.螺旋测微器
D.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b5c929172bbfc21741fa7ef1f53b7bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2858005b9ae89ae080d83dcc13cf8e81.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f66de503c8055c43644b847eba74b50f.png)
E.毫安表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c7e03eed3469e3120060aa375fc327e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7705c06f3cc7f6843796ba83d7c83a77.png)
F.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49f183a0b52a360faa425b974e177926.png)
G.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3b49bd50cc6fc1307c907c8e5bc953de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9d1ce44013cb5ba7c6038dabc2803d.png)
H.蓄电池(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3088c2099211295de775ee33dd1d03fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6699c896d7394a071917fe3922f3864f.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/2f1ac49b4139636fb1809fe970b23a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d1a0fd1ad044a9ecfcba672779bd678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5185fded87ce33ee96df3ad4311d6b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51f736ab50f65b22270093ab541afe9e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e3ef4881bd7c5860178dbdbc7bba6e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
A.电压表0~3V,内阻约为5kΩ;
B.电压表0~15V,内阻约为50kΩ;
C.电流表0~0.6A,内阻约为0.5Ω;
D.电流表0~3A,内阻约为0.1Ω;
E.滑动变阻器(0~5Ω);
F.两节干电池、开关及导线若干。
(1)要求待测金属丝两端的电压从零开始连续变化,电压表应选
(2)请在右侧虚线框中将电路图补充完整。
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/15/a22d3142-3dda-41be-b735-35ce7715da1d.png?resizew=249)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/10/15/accfe38e-810e-488b-9151-f87c5ab4ec37.png?resizew=351)
A.电池(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3088c2099211295de775ee33dd1d03fc.png)
B.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a9d332743ec267382cd99600b757cd3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/159faf4a64cab518863177238d345ff7.png)
C.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4b5c929172bbfc21741fa7ef1f53b7bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42cbb46b2ba641e80ac41c7120a6fe16.png)
D.电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48fade4e14bf5845ff14f9e95bb6bfef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4a6bb65878785532d817f8fd11a9ef3d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ad53b547e11f3e4719a70a4b9564cc8.png)
E.电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b40f1d184152aa3954752ed70e7d1612.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9cd1fc5aefd9457c7ae9fa5acbcdcdd1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14654dff90bd9912cc1ea0945fea0f38.png)
F.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6f7b44014883510d3933bf20d66f44f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d73c327d0f1396ddc8f8a4c1662cd626.png)
G.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0659da9e6ba286b42d8b0986d0c81e9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83fd4d30b27a9f75cae20916d5744baa.png)
H.电键、导线
(1)若所测金属管的电阻约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/146c023fdf3018f507d1db2e51f8d92d.png)
(2)为了尽可能减小测量误差,需要金属管上所加电压能够从零开始变化,且变化范围比较大,请在图乙虚线框中画出符合要求的电路图
(3)利用电压表测量值U、电流表测量值I和题中所述物理量,推导出金属管电阻率的计算公式
待测金属丝:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ef655c6fad2bc260c938e966ad39f98.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/14ba3ede0350b32e2d94c813d27f2183.png)
电压表:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/478abdd84506a8ef759e353a238db6c9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4d64b26bd3eaeebadf07fef49e260282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4875a841b43a4a15718ea3df95fc8cf.png)
电流表:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db586f2c37b26089713ff02346e6d0d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/038b0594fb94fab93fb5f32420ace8cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b34a75c2a392f235c5f07b91d9fb58d5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bc9d1ce44013cb5ba7c6038dabc2803d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2f8cc0a7b2827b82e2ff1c5f491e050.png)
电源:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0862c0c9c58ce303c5654578648cb9ad.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b4f150ab98bde511e0f65d9bafab031.png)
滑动变阻器:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4aa0df7f1e45f9de29e802c7f19a4f64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bbe1cf3e85e43c960470f3773a813bd.png)
螺旋测微器;毫米刻度尺;开关S;导线.
①用螺旋测微器测量金属丝的直径,示数如图所示,读数为
![](https://img.xkw.com/dksih/QBM/2012/6/19/1575268604526592/1575268725153792/STEM/96f7f38d-c368-49a4-9b51-496ca9bddbbd.png?resizew=183)
②若滑动变阻器采用限流接法,为使测量尽量精确,电流表应选
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/493dfb76b4214b676a9f06f0be1f4b4e.png)
电流表A:量程1mA,内阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/945757ada16add096c22e5d38be02f18.png)
电池组E:电动势3V,内阻不计;
电压表V:量程0~3V,内阻约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af9cf1723b8030959ade816b47127606.png)
定值电阻R0:阻值为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0303b4d79507a7b7c1dccaecaebff5ef.png)
滑动变阻器R1:最大阻值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5d757a8853133814c9a9753443c1cf82.png)
滑动变阻器R2:最大阻值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d73e3afd9125734e380b2fe53d0f258.png)
开关一个、导线若干。
(1)小组同学某次用10分度游标卡尺测得金属丝的长度时,不小心使部分刻度被污迹遮住了,如图甲所示,则该次测量的读数为
![](https://img.xkw.com/dksih/QBM/2022/5/31/2991109153751040/2991293155442688/STEM/df8597cf-ae96-48a3-9891-a26da284bed4.png?resizew=312)
(2)小组同学调节滑动变阻器滑片时,使电压表示数能够从零开始连续变化并尽可能减少误差,滑动变阻器应该选用
![](https://img.xkw.com/dksih/QBM/2022/5/31/2991109153751040/2991293155442688/STEM/a28ec100-7ebc-4d45-bca3-ee6c1a70a365.png?resizew=182)
(3)按照电路图连接好电路后,该小组多次改变滑动变阻器触头位置,得到了多组U,I数据,并作出U—I图像,如图乙所示,根据图像可知,金属丝的电阻为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)
![](https://img.xkw.com/dksih/QBM/2022/5/31/2991109153751040/2991293155442688/STEM/176e7e60-9295-4c36-8ad0-303699886fbc.png?resizew=262)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/171102a883b22fe6ca578efc8926f5b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11bc05f41215f9894e11d1df0465751a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a454a2c91ace8ef50412a6adf91f8086.png)
A.两节干电池组成的电池组(电动势
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7214d3ea4528eae48acce84869b97780.png)
B.电阻率待测的金属丝
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7d25313067f3e11f68da496344c4956.png)
C.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4489d9b83072184c0e1d6b09be50ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5db8b00e17ccaab47520ebe262c7aaf5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e02ee9070eb4e1062c0fe59f0752c46c.png)
D.定值电阻
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
E.毫米刻度尺
在尽可能减小测量误差的情况下,请回答下列问题:
![](https://img.xkw.com/dksih/QBM/2022/4/17/2967149004775424/2968154927841280/STEM/d41b2209-5216-488c-92e6-e9fac7ada785.png?resizew=467)
(1)用螺旋测微器测量金属丝直径
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5c02bc0c74292b1e8f395f90935d3174.png)
(2)有三个规格的保护电阻可供选择,
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
A.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d941822843eff28c70023ea38051c307.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec9333c48b31195c71f539b972a98d68.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e236b19d9515b38466870697f193ecd.png)
(3)闭合开关
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a454a2c91ace8ef50412a6adf91f8086.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c27eda162792128da25f541303a3088.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/81dea63b8ce3e51adf66cf7b9982a248.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/963a73a661a554bbf37cc74d702ccea0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/271552971f5fc28dfa881f15bcfa8ddd.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/4a7adf4330db989e3a67fae52c4785e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258e40e3883271c3580c1d3c805dcac6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)