配套习题- 电学综合题解题技巧（2） -【青果学院】

1/5单选题

难度：

1.如图所示电路中，电源两端电压保持不变，设灯丝电阻不随温度变化，R₁为定值电阻，滑动变阻器R₂的最大电阻R_2max=20Ω，当开关S₁断开，S₂闭合，滑动变阻器的滑片P在A端时，标有“6V 12W”字样的灯泡L正常发光，定值电阻R₁消耗的电功率为P₁；当开关S₁断开，S₂闭合，调节滑动变阻器的滑片P至某一位置时，电压表V₁的示数为U₁，电压表V₂的示数为U₂；保持滑动变阻器的滑片P的位置不变，闭合开关S₁、S₂后，滑动变阻器消耗的电功率为P₂，已知U₁：U₂=2：3，P₁：P₂=96：81。求：电路消耗的最小功率为（）

A	6W
B	3W
C	11.7W
D	8W

正确答案：Qw==

PHRhYmxlIGNsYXNzPU1zb05vcm1hbFRhYmxlIGJvcmRlcj0wIGNlbGxzcGFjaW5nPTAgY2VsbHBhZGRpbmc9MCB3aWR0aD02NTAgc3R5bGU9J3dpZHRoOjQ4Ny41cHQ7bWFyZ2luLWxlZnQ6Ny41cHQnPiA8dHI+ICA8dGQgc3R5bGU9J3BhZGRpbmc6Ny41cHQgMGNtIDcuNXB0IDBjbSc+ICA8ZGl2PuW8gOWFs1M8c3ViPjE8L3N1Yj7mlq3lvIDvvIxTPHN1Yj4yPC9zdWI+6Zet5ZCI77yM5ruR5Yqo5Y+Y6Zi75Zmo55qE5ruR54mHUOWcqEHnq6/ml7bvvIxSPHN1Yj4xPC9zdWI+5ZKMTOS4suiBlO+8jOWmguWbvueUsuaJgOekuu+8m1M8c3ViPjE8L3N1Yj7mlq3lvIDvvIxTPHN1Yj4yPC9zdWI+6Zet5ZCI77yM5ruR5Yqo5Y+Y6Zi75Zmo55qE5ruR54mHUOWcqOafkOS9jee9ruaXtu+8jFI8c3ViPjE8L3N1Yj7jgIFSPHN1Yj4yPC9zdWI+5ZKMTOS4suiBlO+8jOWmguWbvuS5meaJgOekuu+8m1M8c3ViPjE8L3N1Yj7jgIFTPHN1Yj4yPC9zdWI+6YO96Zet5ZCI77yM5ruR5Yqo5Y+Y6Zi75Zmo55qE5ruR54mHUOS7jeWcqOafkOS9jee9ruaXtu+8jFI8c3ViPjI8L3N1Yj7lkoxM5Liy6IGU77yM5aaC5Zu+5LiZ5omA56S677ybPC9kaXY+ICA8L3RkPiA8L3RyPiA8dHI+ICA8dGQgc3R5bGU9J3BhZGRpbmc6Ny41cHQgMGNtIDcuNXB0IDBjbSc+ICA8ZGl2PjxpbWcgICB3aWR0aD0xMTggaGVpZ2h0PTEyMSBzcmM9IkM6XFVzZXJzXGdleGluZzAzXEFwcERhdGFcUm9hbWluZ1xRaW5nR3VvRURVXHdvcmRcaXRlbS5maWxlc1xpbWFnZTAwMi5naWYiICAgPjxpbWcgICB3aWR0aD0xNDQgaGVpZ2h0PTExOSBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzAwL0VCL3JCQUNGRk1NZ0NDaThzMTZBQUFUQWxuXzFKMDUyLmpwZWciICAgPjxpbWcgICB3aWR0aD0xMTkgaGVpZ2h0PTEyNiBzcmM9IkM6XFVzZXJzXGdleGluZzAzXEFwcERhdGFcUm9hbWluZ1xRaW5nR3VvRURVXHdvcmRcaXRlbS5maWxlc1xpbWFnZTAwNC5naWYiICAgPjwvZGl2PiAgPC90ZD4gPC90cj4gPHRyPiAgPHRkIHN0eWxlPSdwYWRkaW5nOjcuNXB0IDBjbSA3LjVwdCAwY20nPiAgPGRpdj7vvIgx77yJPGltZyB3aWR0aD0xOTEgaGVpZ2h0PTUxIHNyYz0iQzpcVXNlcnNcZ2V4aW5nMDNcQXBwRGF0YVxSb2FtaW5nXFFpbmdHdW9FRFVcd29yZFxpdGVtLmZpbGVzXGltYWdlMDA1LmdpZiIgICA+PGJyPiAg77yIMu+8ieWcqOS5meWbvuS4re+8jFU8c3ViPjE8L3N1Yj4vVTxzdWI+Mjwvc3ViPj1SPHN1Yj4xPC9zdWI+L1I8c3ViPjI8L3N1Yj49Mi8z77yMPGJyPiAg5Zyo55Sy44CB5LiZ5Lik5Zu+5Lit77yMPGltZyB3aWR0aD0yNDMgaGVpZ2h0PTM2IHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMDAvRUIvckJBQ0ZGTU1nQ0x5SnlLZUFBQVJESEZwa3ZjNzIuanBlZyIgICA+77yMPGJyPiAg55S15rqQ5Lik56uv55S15Y6L5LiA5a6a77yMPGltZyB3aWR0aD0xMTMgaGVpZ2h0PTM5IHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMjMvRDkvckJBQ0UxTU1nQ095Nm5Nb0FBQUo0UThlUUN3OTkuanBlZyIgICA+77yMPGJyPiAgUjxzdWI+TDwvc3ViPj0zUjxzdWI+Mjwvc3ViPi0gNFI8c3ViPjE8L3N1Yj49M8OXPGltZyAgIHdpZHRoPTE1IGhlaWdodD00MyBzcmM9Iml0ZW0uZmlsZXMvaW1hZ2UwMDkuZ2lmIiAgID5SPHN1Yj4xICA8L3N1Yj7vvIw8YnI+ICBSPHN1Yj4xPC9zdWI+PTJSPHN1Yj5MPC9zdWI+PTLDlzPOqT02zqkg77yMPGJyPiAgUjxzdWI+Mjwvc3ViPj08aW1nIHdpZHRoPTE1IGhlaWdodD00MyBzcmM9IkM6XFVzZXJzXGdleGluZzAzXEFwcERhdGFcUm9hbWluZ1xRaW5nR3VvRURVXHdvcmRcaXRlbS5maWxlc1xpbWFnZTAwOC5naWYiICAgPlI8c3ViPjE8L3N1Yj49PGltZyAgIHdpZHRoPTE1IGhlaWdodD00MyBzcmM9IkM6XFVzZXJzXGdleGluZzAzXEFwcERhdGFcUm9hbWluZ1xRaW5nR3VvRURVXHdvcmRcaXRlbS5maWxlc1xpbWFnZTAwOC5naWYiICAgPsOXNs6pPTnOqSDvvIw8YnI+ICDlnKjnlLLlm77kuK3vvIwgPGltZyB3aWR0aD0xOTggaGVpZ2h0PTM5IHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvMjMvRDkvckJBQ0UxTU1nQ1R5dVYwOUFBQU9xQlRlcVVvMTMuanBlZyIgICA+77yMVT0zVTxzdWI+TDwvc3ViPj0zw5c2Vj0xOCBW77yMPGJyPiAg5Zyo5LmZ5Zu+5Lit77yM5b2T5ruR5Yqo5Y+Y6Zi75Zmo5o6lQeeUtei3r+eUtemYu+acgOWkp+aXtu+8jOeUtei3r+a2iOiAl+aAu+eUteWKn+eOh+acgOWwj++8jCA8YnI+ICA8aW1nIHdpZHRoPTMzOSBoZWlnaHQ9NDAgc3JjPSJodHRwczovL3AxLnFpbmdndW8uY29tL0cxL00wMC8wMC9FQi9yQkFDRkZNTWdDU0JVSTU0QUFBVmxoNS1fSHMwOS5qcGVnIiAgID7jgII8L2Rpdj4gIDwvdGQ+IDwvdHI+PC90YWJsZT48ZGl2Pg==

2/5单选题

难度：

2.如图所示的电路中，电源两端的电压保持不变。闭合开关S、S₁，当滑片P移至滑动变阻器R₂的A端时，电压表V₁的示数为U₁，电压表V₂的示数为U₂，电流表A的示数为I₁，滑动变阻器R₂消耗的电功率P₂为3W。当只闭合开关S，将滑片P移至滑动变阻器R₂的中点时，电压表V₁的示数为U₁¢，电压表V₂的示数为U₂¢，电流表A的示数为I₂。闭合开关S、S₁，当滑片P移至滑动变阻器R₂的B端时，电流表A的示数为I₃，电阻R₃的电功率为P₃。已知U₁＝

U₁¢，U₂＝4U₂¢。则下列说法正确的是（）

A	I₁：I₂= 1:4 P₃=12W
B	I₁：I₂=4:1 P₃=12W
C	I₁：I₂=4:3 P₃=16W
D	I₁：I₂=4:1 P₃=16W

正确答案：RA==

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

3/5单选题

难度：

3.如图所示的电路中，电源两端的电压和灯泡的电阻均保持不变。当只闭合开关S和S₁时，灯L₁正常发光，电流表 A 的示数为 I ₁，电压表 V₁的示数为 U₁ ，电压表 V₂的示数为U₂，电阻R₃消耗的电功率为P₃；当只闭合开关S和S₂时，电流表 A的示数为I ₂，电压表V₁的示数为U^/₁，电阻 R₄消耗的电功率为P₄。已知： 3 U₁= 2 U₂，U₁= 2 U^/₁，P ₃= 2W，P₄=2.5 W。通过开关的断开或闭合，电路处于不同状态。在电路的各工作状态中，消耗的最大电功率为Pmax 最小电功率为Pmin ，则Pmax ：Pmin（）

A	5:2
B	21:5
C	48:5
D	16:3

正确答案：Qw==

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

4/5多选题

难度：

4.如图所示电路，电源两端电压保持不变，滑动变阻器的最大电阻值为R₁，R₂为定值电阻，灯泡L标有“12V 9W”字样，且不计灯丝电阻随温度的变化。当开关都闭合时，灯泡L恰能正常发光。将开关S₁、S₃断开，S₂闭合后，改变滑动变阻器的滑片P的位置，使滑动变阻器连入电路的电阻分别为0.25R₁和R₁，这两种情况下，滑动变阻器消耗的电功率相等。当开关S₁、S₂断开，S₃闭合，滑片P在变阻器的左端时，灯泡L的实际电功率为额定电功率的

。下列说法正确的是：（）

A	灯泡正常发光时电流表的示数为1.25A
B	滑动变阻器最大阻值为48Ω
C	通过开关断开或闭合，电路消耗的最小功率为2W
D	灯泡正常发光时，R₂消耗的的功率为6W

正确答案：QixDLEQ=

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

5/5单选题

难度：

5.如图所示，电源电压保持不变，滑动变阻器P最大阻值为R₁=40Ω，小灯泡电阻始终保持不变。当开关S、S₁、S₂均闭合且滑片P滑到b端时，电流表A₁、A₂的示数I₁、I₂之比为7:4，小灯泡L的电功率为4.8W；当开关S闭合，S₁、S₂断开且滑片P置于滑动变阻器中点时，电流表A₁的示数I₁´是I₁的3/7倍。则：

A	R₂的阻值为24Ω
B	R₂的阻值为12Ω
C	整个电路的最小功率为6W
D	整个电路的最小功率为2.4W

正确答案：RA==

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