灯泡电阻为:R1=(U^2)/P=(6Vx6V)/3w=12欧
正常发光是电流为:I1=P/U=3W/6V=0.5A
P在中点时,电阻为最右端的一半即1/2R2=U2/I2=(8V-6V)/0.5A=4欧
所以R2=8欧
在最右端是小灯泡的实际功率:P'=I^2R1=[U/(R1+R2)]^2R2=[8V/(12欧+8欧)]^2X12欧=1.92W
灯泡电阻为:R1=(U^2)/P=(6Vx6V)/3w=12欧
正常发光是电流为:I1=P/U=3W/6V=0.5A
P在中点时,电阻为最右端的一半即1/2R2=U2/I2=(8V-6V)/0.5A=4欧
所以R2=8欧
在最右端是小灯泡的实际功率:P'=I^2R1=[U/(R1+R2)]^2R2=[8V/(12欧+8欧)]^2X12欧=1.92W