题干

在图所示的电路中,电源电压保持不变。电阻 R1 的阻值为20欧,现将两个电流表 A1A2 分别串接在电路中,向左移动滑动变阻器 R2 的滑片P,每次移动滑片P,均使变阻器 R2 连入电路的电阻减少相同的阻值,两个电流表的示数如下表所示。
求电源电压U。
若变阻器 R2 连入电路中的阻值为50欧时,求干路的电流I。
请通过计算说明电流表 A2 串接在电路中的位置。
上一题 下一题 0.0难度 选择题 更新时间:2017-04-12 02:01:05

答案(点此获取答案解析)

解: 由电路图可知,两电阻并联,由表格中数据可知,电流表A1测量通过定值电阻的电流,由 I=
U
R
可得

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