![](https://img.xkw.com/dksih/QBM/editorImg/2024/3/27/cccd9d29-aaa7-41d5-9bbd-ebea704723b1.png?resizew=748)
(1)小明连接如图甲所示电路,检查电路发现有一条导线连接错误,请在图甲中错误导线上画“×”,并用笔画线代替导线将电路连接正确
(2)排除故障后,当接入5Ω定值电阻时,调节滑动变阻器的滑片到某位置,电流表的示数如图乙所示为
(3)将20Ω的电阻更换成25Ω的电阻时,为完成实验,应该将电源电压调
(4)小明在完成上述实验后,想测量小灯泡两端电压为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbe5cb81b72e94f92d2aaecd553daac2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0a4683c15eff45ff06eb8072e7ddbb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c76eaa6628066e3bd985ca5945b5839.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/291b9f95d71ba66b92f981069cd1e63e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9b4a83b9aebebf29de0c4406ebf894.png)
①只闭合开关S、
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
②保持滑动变阻器滑片位置不变,只闭合开关S、S2,读出电压表示数为U1。接着调节滑动变阻器的滑片P,使电压表的示数为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbe5cb81b72e94f92d2aaecd553daac2.png)
③接着断开开关
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e0bd63f55069a3bc870915010b39225.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e097c8d4c948de063796bd19f85b3a9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f833a7beb83820ecede0234c671f1878.png)
④小灯泡L两端电压为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dbe5cb81b72e94f92d2aaecd553daac2.png)
2 . 如图所示的实物电路由电源、开关S₁、S₂、灯泡L₁、L₂和甲、乙两个电表组成,闭合开关S₁、S₂后,小灯泡L₁和L₂均正常发光,两个电表均有示数,关于此时的电路,下列说法正确的是( )
A.甲是电流表,能测量干路中的电流 |
B.甲是电压表,能测量 L₁两端的电压 |
C.乙是电流表,能测量干路中的电流 |
D.乙是电压表,能测量L₂两端的电压 |
3 . 用如图1电路测量一只标有“”字样的小灯泡的电功率。
(1)请用笔画线代替导线将电路连接完整,要求:滑动变阻器滑片P在右端时,电路的电流最小。
(2)闭合开关,发现电流表、电压表均有示数,但小灯泡不发光,其原因可能是
A.小灯泡断路 B.小灯泡短路
C.开关接触不良 D.滑动变阻器连入电路的阻值过大
(3)移动滑片P直至电压表示数为
(4)多次测量后,根据数据得到图3的图象,发现随着实际电压增大,灯丝电阻
(5)创新小组在实验室发现一只灯泡,只标有额定电流,用电阻箱和电流表设计了如图4电路测量灯泡额定功率,方法如下:
①只闭合开关,调节电阻箱直至
;
②同时闭合开关、
,调节电阻箱直至电流表示数为
,记录电阻箱阻值
;
③灯泡的额定功率的表达式为
②滑动变阻器取值范围为3~30Ω
③小灯泡的额定功率为0.75W
④整个电路消耗的最大功率为2W
A.只有③④正确 | B.只有①②正确 |
C.只有①②④正确 | D.只有②③④正确 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9e65b2e896a5c2371ef4d17d58d2709.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a2c4640b2bee411935f588fc5433c74.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910f1655703721b51006b887a2394b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/779629f16056a50f4c06e3996d8e1c82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acf35aa115963656d885b6440d6caa2c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b9352217b24f53765f9ef28e7b0104a2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/779629f16056a50f4c06e3996d8e1c82.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/910f1655703721b51006b887a2394b6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/524e794d691cfc28b4d5e857af919639.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9efc18a5bb2e53586331b2a58538a48b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/19f20f21a9d50b61dac519a3ddab539d.png)
A.电源电压为15V | B.![]() |
C.20s内,![]() | D.滑动过程中![]() |
(2)星星用调节好的天平测量材料的质量,天平平衡时,右盘中砝码的质量及游码在标尺上的位置如图乙所示,则该材料的质量为
(3)接着用图丙所示的方法测出了该材料的体积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dc6d1d99afa158b4ba4fc0dae562fcc1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a85ab212fd29e35beb6d24c057dcac.png)
(4)爱动脑筋的星星同学利用这个材料,只用电子秤测量出了牛奶的密度,实验步骤如图:
①电子秤放在水平桌面上,放上装有适量牛奶的杯子,示数如图丁所示;
②把材料用细线绑好,缓慢放入装有牛奶的杯子中,示数如图戊所示;
③用手提起细线,让被测材料离开杯子底部,继续全部浸没在牛奶中,示数如图己所示。经测量杯子的外底面积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b12d5b15f6979cd665d54fd17341fc2f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/55a85ab212fd29e35beb6d24c057dcac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f0a3df0d2d0e5bb4f1811ff61ca3813.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5e4211d2ef1231c5a4e419c76fb5695.png)
A.A的重力为0.5N |
B.A恰好与B接触时,此时水对容器底的压强为2000Pa |
C.当加水质量为2kg时,B对A的压强![]() ![]() |
D.当细绳拉力为0N时,A底部所受到的液体压力为15N |
(1)当I=0.6A时,滑动变阻器的电功率
(2)滑动变阻器的最大阻值;
(3)将电源电压调为6V,电压表改接0~3V量程,为保证电路安全,求总功率的变化量;
(4)若使滑动变阻器可任意调节(从0调到最大阻值),且使电流表指针示数不低于满刻度的
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5e6486784415f3537c9a13556c05d893.png)
A.恰好都升高了2Δt℃ |
B.都高超过2Δt℃ |
C.都不足2Δt℃ |
D.二种方式只有一种正好升高2Δt℃ |