有两个电阻R1、R2,若只将R1接到电源上,1min内电流做功为160焦有两个电阻R1、R2,若只将R2接到同一电源上
问题描述:
有两个电阻R1、R2,若只将R1接到电源上,1min内电流做功为160焦有两个电阻R1、R2,若只将R2接到同一电源上
答
U^2/R1T=160 R1=U^2T/160 R2=U^2T/240 R1+R2=U^2T*(1/160+1/240) W=PT=U^2/(R1+R2)T =U^2/(U^2T*(1/160+1/240))*T =1/(1/160+1/240) =160*240/(160+240) =96J