![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/6/40143371-ecb6-423b-a2d1-5f84c9ab2fc6.png?resizew=478)
(1)用游标卡尺测量金属丝的长度L,用螺旋测微器测量金属丝的直径D,测量结果分别如图甲所示,则
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd1846e964fd60c54888a3c706a97442.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9a6d85799453899836bc34ad276ec80e.png)
(2)用多用电表的欧姆挡粗测金属丝的电阻值,应该选用的倍率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3a1e976dc7ccea4600a8ad1121760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d55519bd96aba05e6f1533ddc7bb63fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eebdb972b35aaa81a6662aaf8db1c282.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/6/4b2c1fb1-4272-4960-a43a-d2d949d45adf.png?resizew=272)
(3)若采用“伏安法”较为准确地测量金属丝的电阻,除待测金属丝外,实验室提供了学生电源E(电动势为4V)、开关S、导线若干,还备有下列实验器材:
A.电压表V(0~3V,内阻约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a243239aa0edd6d57279d3771b255ead.png)
B.电流表A(0~300mA,内阻约为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b132e0cbd0e446630f4bb65804ce581.png)
C.滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/281e8f4804c29190f5535f58d39341a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc0a2433d35c94a4e681f225e25026e.png)
(4)请在图丙的方框内画好电路图
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/6/86b14746-ed22-4508-82b6-5c0fca63bc0f.png?resizew=409)
(5)若测得金属丝的电阻为R,则金属丝的电阻率
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
(6)若考虑到电表内阻的影响,该方法测得的电阻率比真实值
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aeac921b936467bb4a262537616cfac2.png)
(1)用螺旋测微器测量其横截面直径如图甲所示,由图可知其直径为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efa9fbcfb9595e2f031aa691db4564b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/2/4ae26d40-aea2-409b-98e3-f8bd0ccb45df.png?resizew=466)
(2)为了减小实验误差,需进一步测量圆柱体的电阻,除待测圆柱体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ce2581ae160692cd7e2686226fe5e2c6.png)
A.电压表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48fade4e14bf5845ff14f9e95bb6bfef.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/549b8489b17608927e9ba3f6d2da1f16.png)
C.电流表
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/024e2379c58191758f8bd7602a6bcb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/db586f2c37b26089713ff02346e6d0d8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d941822843eff28c70023ea38051c307.png)
E. 滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a237d11095e95fe4a44f6b8e59084fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1bc0a2433d35c94a4e681f225e25026e.png)
F. 滑动变阻器
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04131caf9c109d886a52a8762fd6a9aa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/572c420017553eab82e08f02e93882c9.png)
G. 直流电源E(电动势为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b26d0e154ef213ebe194b8b5e519f13.png)
H. 开关S,导线若干
(3)请设计合理的实验电路,并将电路图画在虚线框中
![](https://img.xkw.com/dksih/QBM/editorImg/2023/8/2/137cf1b1-7e8d-417c-a065-e131188a6313.png?resizew=164)
(4)若流经圆柱体的电流为I,圆柱体两端的电压为U,圆柱体横截面的直径和长度分别用D、L表示,则用D、L、I、U表示该圆柱体电阻率的关系式为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/28/3393cc7a-1c4a-4e69-9d6f-592844560a4e.png?resizew=522)
(1)该同学用多用电表欧姆档测电阻丝的阻值,当用“×10”档时发现指针偏转角度过大,重新选择档位并进行电阻调零后,指针静止时位置如图甲所示,其读数为
然后用螺旋测微器测其直径,如图乙所示,为
(2)为了尽可能准确测量其电阻,电源选用2节干电池,滑动变阻器采用分压接法,请完成实物图丁的连线
![](https://img.xkw.com/dksih/QBM/editorImg/2023/7/28/821e2b4d-19e4-4208-aea4-30b00fa512a3.png?resizew=175)
(3)若通过多次测量得到的电阻的伏安特性曲线(
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd1fd3cc33190245791eddc26c629b9f.png)
4 . 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=
![](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/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4388d61dbe462c603456ba1ec9ce7834.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6c900495736982c251da7b4919cdf59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6c900495736982c251da7b4919cdf59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a2c4640b2bee411935f588fc5433c74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c88a855dd0eb3836cc9f8d4c2fd73f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e2599548b7b123f3c8d0b91aacd5de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5cc26fa4a4ce27772c553a3e5516389.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d43eb0b274e00cbbc4a210da4165042.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/530f5b63e797195906285c0c03eb9276.png)
(1)电路连接
图(a)为实验原理图.在图(b)的实物图中,已正确连接了部分电路,只有
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/98e2599548b7b123f3c8d0b91aacd5de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a2c4640b2bee411935f588fc5433c74.png)
①测量并记录样品池内壁的长宽高.在样品池中注满待测盐水
②闭合开关
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d43eb0b274e00cbbc4a210da4165042.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/530f5b63e797195906285c0c03eb9276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/535eee3cd3bd5abaa1547da2db181c69.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2f1ac49b4139636fb1809fe970b23a87.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58b5bd7cf13ef88690281ce09f1d3471.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/530f5b63e797195906285c0c03eb9276.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40e85b9a88eecb81b1b5703b01baaac3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d1a0fd1ad044a9ecfcba672779bd678.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/58b5bd7cf13ef88690281ce09f1d3471.png)
④断开开关
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d43eb0b274e00cbbc4a210da4165042.png)
(3)根据上述数据,计算得到样品池两电极板间待测盐水的电阻为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0047f659c182291c84c224df6b5e993f.png)
b.将平行排列的四根金属探针甲、乙、丙、丁与样品接触,其中甲、乙、丁位置固定,丙可在乙、丁间左右移动;
c.将丙调节至某位置,测量丙和某探针之间的距离L;
d.闭合开关S,调节电阻箱R的阻值,使电流表示数I = 0.40A,读出相应的电压表示数U,断开开关S;
e.改变丙的位置,重复步骤c、d,测量多组L和U,作出U—L图像如图(b)所示,得到直线的斜率k。
回答下列问题:
(1)L是丙到
(2)写出电阻率的表达式ρ =
(3)根据图像计算出该样品的电阻率ρ =
(1)分别使用刻度尺和螺旋测微器测量金属棒的长度L和直径d,某次测量金属棒的直径示数如图所示,直径d=
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/30/58cd72d4-5f91-462c-8817-5941483a73b5.png?resizew=164)
(2)现备有下列器材:
待测金属棒:Rx(阻值约5Ω);
电压表:V1(量程3V,内阻约3kΩ);V2(量程15V,内阻约9kΩ);
电流表:A1(量程0.6A,内阻约0.2Ω);A2(量程3A,内阻约0.05Ω);
电源:E1(电动势3V,内阻不计);
滑动变阻器:R(最大阻值约20Ω);
开关S;导线若干。
为使测量尽量精确,电压表应选
(3)若滑动变阻器采用分压式接法,正确选择仪器后请在图中用笔画线代替导线,完成实物电路的连接
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/30/495c84e1-52e9-4ce4-a406-640fd1b4a0c9.png?resizew=248)
(4)用伏安法测得该金属棒的电压和电流,并作出其伏安特性曲线如图所示,若图像的斜率为k,则该金属棒的电阻率ρ=
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/30/83193048-2ca8-40ce-9029-ddde4b97252e.png?resizew=152)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/31/57d6e8ed-f2b8-466d-a789-abef56711f14.png?resizew=678)
(1)如图1所示,用螺旋测微器测得铜芯的直径为
(2)如图2所示,取整捆铜芯线、2节干电池和相关器材,为了使电压表示数能从零开始连续调节,请补充连接好实物电路
(3)正确连接实物电路后,闭合开关,调节滑动变阻器,测得电流表示数为2.00A,此时电压表示数如图3所示,则其示数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd01fcc8715e9de163e2dc3058d9a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9942091e83e1d59af01f499a0caee212.png)
(4)实验小组查阅教材得知:在t0=20ºC时铜的电阻率为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e2554579f1bed7f3f42b873da9b43a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/59dd01fcc8715e9de163e2dc3058d9a1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/92e2554579f1bed7f3f42b873da9b43a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aaf3a1e976dc7ccea4600a8ad1121760.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/5/31/fbfb8501-d56d-480b-954e-2abb5f7d1fa4.png?resizew=638)
(1)甲图的读数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c98c59cd4749afdd21e73529fc84323.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21f3bf70722b22983c120d008d097602.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5be4dd62f994aa9b12b4da0ccba9ac60.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cffa35373ec4e4684107b42adb7a5161.png)
(2)对丙图实验时闭合开关,从右向左逐渐改变鳄鱼夹的位置,记录鳄鱼夹每一个位置对应的金属丝接入电路的有效长度L,以及对应的电流表A的示数I,得到多组
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/06cbd4e914b6e75ed3dd25720ff9266e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e619475201be944ce3c0275e0a5684cd.png)
(3)若丁图的斜率为k,纵轴的截距为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a6616da8f7c03dc5d8f1ed993d3cfa25.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/258e40e3883271c3580c1d3c805dcac6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b30db97c39edcede2f0e7d4e075fecec.png)
(4)若电流表A内阻不可忽略且未知,则金属丝电阻率的测量值