I have half a meter of 18 AWG (1.02mm diameter) stranded copper wire and I am planning to run 12 volts with a maximum 6 amp load.
Determining the cross sectional area = 0.51mm^2 * PI
, gives me ~8.17e-07 meters
.
Determining the resistance R = (1.72e-8 * 0.5 meters) / area
, gives ~0.0105 Ohms
resistance for the half meter length.
My attempt to then determine voltage drop is V = I * R
, V = 6 * 0.0105
, giving a voltage drop of ~0.063
(~11.94V
)
Why then do many online calculators have a multiplier of 2
on this drop? (~11.87V
)