一阻值恒定的电阻,当两端加上10 V的直流电压时,测得它的功率为P;当两端加上某一正弦式交流电压时,测得它的功率为P/2,由此可知该交流电压的有效值为________V,最大值为________V. 答案: 10 解析:P=,故R=,功率为,故U有=V,Um=V=10 V.
-Jim!I have finished ________ my homework.Let's go and play.
-That's great.
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do
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to doing