1/5单选题
难度：
1.
如图所示，电源电压保持不变. 当开关S1闭合、S2断开时，电流表的示数为0.2A；当开关S1、S2都闭合时，电流表的示数为0.8A. 则电阻R1与R2的比值为（ ）
| A | 1：4 |
| B | 1：3 |
| C | 4：1 |
| D | 3：1 |
- 提示1：
- PHA+5b2T5byA5YWzUzxzdWI+MTwvc3ViPuWQiOOAgVM8c3ViPjI8L3N1Yj7mlq3lvIDml7Ys5Lik55S16Zi75Liy6IGUPC9wPg==
- 提示2：
- PHA+5b2T5byA5YWzUzxzdWI+MTwvc3ViPuOAgVM8c3ViPjI8L3N1Yj7pg73pl63lkIjml7bvvIznlLXpmLtSPHN1Yj4yPC9zdWI+6KKr55+t6LevPC9wPg==
正确答案：Qg==
PGRpdj7lvZPlvIDlhbNTPHN1Yj4xPC9zdWI+5ZCI44CBUzxzdWI+Mjwvc3ViPuaWreW8gOaXtizkuKTnlLXpmLvkuLLogZTvvIzmnInvvIhSPHN1Yj4xPC9zdWI+K1I8c3ViPjI8L3N1Yj7vvIkwLjJBPVU8L2Rpdj48ZGl2PuW9k+W8gOWFs1M8c3ViPjE8L3N1Yj7jgIFTPHN1Yj4yPC9zdWI+6YO96Zet5ZCI5pe277yM55S16Zi7UjxzdWI+Mjwvc3ViPuiiq+efrei3r++8jFI8c3ViPjE8L3N1Yj7CtzAuOEE9VTwvZGl2PjxkaXY+6IGU56uL5Y+v5b6X77yM5Lik55S16Zi75LmL5q+U5Li6MTozPC9kaXY+
2/5单选题
难度：
2.
如图，V1 、V2的示数之比为3:5，则R1:R2的比值为（ ）
| A | 3:5 |
| B | 5:3 |
| C | 3:2 |
| D | 2:3 |
- 提示1：
- PHA+5Liy6IGU55S16Lev5Lit55S15Y6L5ZKM55S16Zi75oiQ5q2j5q+UPGJyPjwvcD4=
- 提示2：
- PHA+55S15Y6L6KGoVjHmtYtSMeS4pOerr+eUteWOizxicj48L3A+
- 提示3：
- PHA+55S15Y6L6KGoVjLmtYtSMeOAgVIy5oC755S15Y6LPGJyPjwvcD4=
正确答案：Qw==
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
3/5单选题
难度：
3.
如图所示，电源电压不变，开关S由断开到闭和时，电压表的示数之比为3∶8，则电阻R1∶R2的比值为（ ）
| A | 3:5 |
| B | 3:8 |
| C | 5:3 |
| D | 8:3 |
- 提示1：
- PHA+5byA5YWz5pat5byA77yM55S15Y6L6KGo5rWLUjLkuKTnq6/nlLXljos8YnI+PC9wPg==
- 提示2：
- PHA+5byA5YWz6Zet5ZCI77yMUjHooqvnn63ot6/vvIznlLXljovooajnm7jlvZPkuo7mtYvnlLXmupDnlLXljos8YnI+PC9wPg==
正确答案：Qw==
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
4/5单选题
难度：
4.
如图所示电路中，电源电压不变. 开关S闭合后，电压表V1、V2示数之比为3：5；断开开关S，把电压表V1换成电流表A1，把电压表V2换成电流表A2，闭合开关S，电流表A1、A2示数之比为5：9. 则下列结果正确的是（ ）
| A | R1：R2=5：3 |
| B | R3：R1=1：3 |
| C | R2：R3=5：3 |
| D | R1：R2：R3=1：2：3 |
- 提示1：
- PHA+55S16KGo5Li655S15Y6L6KGo5pe2LOeUtei3r+S4uuS4suiBlOeUtei3ryznlLXljovooahWPHN1Yj4xPC9zdWI+5rWLUjxzdWI+Mjwvc3ViPuWSjFI8c3ViPjM8L3N1Yj7kuKTnq6/nlLXljossVjxzdWI+Mjwvc3ViPua1i1I8c3ViPjE8L3N1Yj7lkoxSPHN1Yj4yPC9zdWI+5Lik56uv55S15Y6LPC9wPg==
- 提示2：
- PHA+5b2T55S16KGo5Li655S15rWB6KGo5pe2LOeUtei3r+S4uuW5tuiBlOeUtei3ryxBPHN1Yj4xPC9zdWI+5rWLUjxzdWI+Mjwvc3ViPuWSjFI8c3ViPjM8L3N1Yj7mgLvnlLXmtYEsQTxzdWI+Mjwvc3ViPua1i1I8c3ViPjE8L3N1Yj7lkoxSPHN1Yj4yPC9zdWI+5oC755S15rWBPC9wPg==
正确答案：RA==
PGRpdj7nlLHkuo7mmK/pgInmi6npopgs5Y+v5Lul55u05o6l5bCG6YCJ6aG55Luj5YWl5q+U5L6L5byP5LitLOWImeaciUTmraPnoa48L2Rpdj4=
5/5单选题
难度：
5.
如图所示的电路中，当开关Ｓ闭合，甲乙两表示电压表时，示数之比Ｕ甲︰Ｕ乙＝３︰２；当开关Ｓ断开，甲、乙两表是电流表时，则两表的示数之比Ｉ甲︰Ｉ乙为（ ）
| A | ２︰１ |
| B | ３︰１ |
| C | ２︰３ |
| D | １︰３ |
- 提示1：
- PHA+55Sy5LmZ5Li655S15Y6L6KGo5pe277yM55Sy5rWL5oC755S15Y6L77yM5LmZ5rWLUjxzdWI+Mjwvc3ViPueahOeUteWOi++8jDwvcD4=
- 提示2：
- PHA+55Sy5LmZ5Li655S15rWB6KGo5pe277yM55Sy5rWLUjxzdWI+Mjwvc3ViPueahOeUtea1ge+8jOS5mea1i+W5sui3r+eUtea1gTxicj48L3A+
正确答案：RA==
PGRpdj7nlLLkuZnkuLrnlLXljovooajml7bvvIznlLLmtYvmgLvnlLXljovvvIzkuZnmtYtSPHN1Yj4yPC9zdWI+55qE55S15Y6L77yM5b6XUjxzdWI+MTwvc3ViPu+4sFI8c3ViPjI8L3N1Yj49Me+4sDI8L2Rpdj48ZGl2PueUsuS5meS4uueUtea1geihqOaXtu+8jOeUsua1i1I8c3ViPjI8L3N1Yj7nmoTnlLXmtYHvvIzkuZnmtYvlubLot6/nlLXmtYHvvIzmiYDku6XnlLXmtYHmr5TkuLrkuoYx77iwMzxicj48L2Rpdj4=