如图所示，理想变压器给负载R供电．保持输入的交变电压不变，各交流电表对电路的影响

发布时间：2017-07-02 00:25 │ 来源：www.tikuol.com

题型：选择题

问题：

如图所示，理想变压器给负载R供电．保持输入的交变电压不变，各交流电表对电路的影响不计。当负载电阻的滑动触头向下移动时，图中各交流电表的示数及变压器的输入功率P的变化情况是

[ ]

A．V₁和V₂不变，A₁和A₂增大，P增大

B．V₁和V₂不变，A₁增大，A₂减小，P增大

C．V₁和V₂不变，A₁和A₂减小，P减小

D．V₁不变，V₂增大，A₁减小，A₂增大，P减小

考点：变压器电压、电流、电功率与匝数的关系

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