hitung hambatan lampu besar mobil 40W dirancang untuk 12V?

P = V² / R
R = V² / P = (12 V)² / (40 W) = 3,6 Ω

P = V. I
40 = 12. I
40/12 = I
10/3 =I

I = V/R
10/3 = 12/R
10R =12.3
R = 3,6