运用知识解决问题:(1)电炉子工作时,电炉丝断了,将断的电炉丝接好后重新接入电路,工作不长时间又会 (2009?崂山区模拟)运用知识解决问题:(1)电炉子工作时...
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解:(1)根据公式Q=U2 |
R |
故答案为:(1)
U2 |
R |
(2)①S1闭合时,两灯都不亮,整个电路都不工作,说明S1在干路中;
②闭合S2时,红灯都亮,绿灯L2不亮,电流表A2有示数,说明S2控制绿灯的工作,电流表可能在干路中,也可能与红灯串联;
③闭合S1和S2时,红、绿灯都亮,电流表都有示数,并且I1<I3,I3>I2,结合①②可得,红绿灯并联,开关S2控制整个电路,S1控制红灯所在的支路;电流表A2测量干路电流,电流表A1与红灯串联.
(3)①R1=
|