Question

电路电源电压U不变,S断开与闭合,电流表两次示数之比为3:5.求：（1)S断开时,电阻R1、R2的电功率之比；

Answer 1

(U/R1):(U/(R1+R2)) = 5:3

(R1+R2)/R1 = 5/3, R2 = (2/3)R1

(1) R1:R2 = 3:2

(2) 呃公式记不太清楚了,但如果功率是W=(U^2)/R的话,

[(U^2)/R1]{闭合}:[(U^2)/(R1+R2)]{断开}

= (1/R1):[1/(R1+R2)]

= (R1+R2)/R1

= 5/3

= 5:3.

手打的,渣排版,括号啊平方啊大小写啊什么的记得改一下……另外如果表示计算看不懂建议用纸自己写一遍吧= =