Question

用一只1.5V,2.5W的小电珠与一个电阻R串联,接於电动势E=6V,

Answer 1

设电路中的电流为I,小电珠的电阻为R1.

有题可知 2.5 = 1.5*I

2.5 = 1.5^2/R1

I*(R1 + R + Ro) = 6

联立方程组解得 I = 5/3

R1 = 0.9

R = 0.3