1/5单选题
难度：
1.R1、R2两个电阻并联后接入电路中，它们的电功率之比P1∶P2=9∶4，则R1、R2两个电阻阻值之比是（）
| A | 9∶4 |
| B | 4∶9 |
| C | 3∶2 |
| D | 2∶3 |
- 提示1：
- 5bm26IGU55S16Lev5Lit5ZCE5pSv6Lev55S15Y6L55u4562J
正确答案：Qg==
5bm26IGU55S16Lev5Lit5ZCE5pSv6Lev55S15Y6L55u4562J77yM55S15Yqf546H5ZKM55S16Zi75oiQ5Y+N5q+U77yM55Sx5LqO55S15Yqf546H5LmL5q+U5pivOTo077yM5omA5Lul55S16Zi75LmL5q+U5bqU6K+l5pivNDo577yM5pWF6YCJQi4=
2/5单选题
难度：
2.一个“220V1000W”的电炉子，将它改装后接在110V的电源上，但功率保持不变，可行的办法是（ ）
| A | 将电炉丝分成等长的两段，并联后接入电路中 |
| B | 将电炉丝分成等长的两段，取其中一段接入电路中 |
| C | 将电炉丝分成等长的四段，取其中两段并联后接入电路中 |
| D | 将电炉丝分成等长的四段，并联后接入电路中 |
- 提示1：
- 55S16Zi75YC85LiO5a+85L2T55qE6ZW/5bqm5oiQ5q2j5q+U77yM55S16Zi75YC85LiO5a+85L2T55qE5qiq5oiq6Z2i56ev5oiQ5Y+N5q+U
- 提示2：
- 55S16Zi75Lid562J6ZW/55qE5YiG5oiQMuauteWQju+8jOW5tuiBlOaOpeWcqOeUtei3r+S4re+8jOeUtemYu+WAvOWPmOS4uuWOn+adpeeahOWbm+WIhuS5i+S4gA==
正确答案：QQ==
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
3/5单选题
难度：
3.有两个额定功率相同的灯泡，接在一个电源上．以下的描述中，正确的是（ ）
| A | 两个灯泡的亮度一定相同，且与电流、电阻无关 |
| B | 只有把它们并联起来亮度才相同，串联使用时亮度不相同 |
| C | 实际电压分别与它们的额定电压相同时，亮度才相同 |
| D | 它们正常工作时亮度相同并且电流也相等 |
- 提示1：
- 54Gv5rOh55qE5Lqu5bqm5piv55Sx5a6e6ZmF5Yqf546H5Yaz5a6a55qE
- 提示2：
- 5Zyo5Liy6IGU55S16Lev5Lit77yM55S16Zi76LaK5aSn55qE54Gv5rOh77yM5a6e6ZmF5Yqf546H6LaK5aSn
正确答案：Qw==
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
4/5单选题
难度：
4.同学们用如图所示电路探究“电功率与电流的关系”.以下观点不正确的是 （）
| A | 实验要选取规格不同的灯泡 |
| B | 实验中将两灯并联控制了灯两端电压相同 |
| C | 将滑动变阻器串联在干路中可以完成实验 |
| D | 将题中并联电路改为串联电路也可以完成实验 |
- 提示1：
- 5Zyo5bm26IGU55S16Lev5Lit77yM55So55S15Zmo5Lik56uv55qE55S15Y6L5piv55u4562J55qE
- 提示2：
- 5ruR5Yqo5Y+Y6Zi75Zmo5Y+v5Lul5pS55Y+Y55S16Lev5Lit55qE55S15rWB
正确答案：RA==
6aKY55uu6KaB56CU56m255qE5piv5bm26IGU55S16Lev5Lit55S15Yqf546H5LiO55S15rWB55qE5YWz57O777yMROmAiemhueS4reWmguaenOWwhuW5tuiBlOeUtei3r+aUueS4uuS4suiBlOeUtei3r++8jOS4suiBlOeUtei3r+eahOeUtea1geebuOetie+8jOS4jeiDvei+vuWIsOWunumqjOebrueahO+8jOaVhemAiUQu
5/5单选题
难度：
5.
李明同学为了探究“电功率与电阻的关系”，他找来额定电压均为6V的L1、L2 两只灯泡．将两灯串联起来，按照图所示的电路开始了实验探究，闭合开关后，看见灯L2微微发光，灯L1几乎不发光，不考虑灯丝电阻值随温度的变化，则关于两灯的电阻R1和R2、两灯的额定功率P1和P2的大小关系成立的是（）
| A | R1> R2 P1 > P2 |
| B | R1< R2 P1 < P2 |
| C | R1> R2 P1 < P2 |
| D | R1< R2 P1 > P2 |
- 提示1：
- PHA+5Liy6IGU55S16Lev5Lit77yM55So55S15Zmo55qE55S16Zi76LaK5aSn77yM5a6e6ZmF5Yqf546H6LaK5aSnPC9wPg==
- 提示2：
- PHA+6aKd5a6a55S15Y6L55u45ZCM55qE55So55S15Zmo77yM55S16Zi75bCP55qE55So55S15Zmo77yM6aKd5a6a5Yqf546H5aSnPC9wPg==
正确答案：RA==
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