wire ab of length and wire bc of length are attached to a ring
UF Cable-Underground Feeder. Timothy Thiele. When considering the appropriate wire size for a circuit, don't forget to take the circuit length into consideration. Electrical wire, no matter what material it is made out of, has a certain resistance to it.With an increase in cable length, the resistance causes a voltage drop in the circuit.The solution is easy enough. You should just choose the next sized larger ampacity wire size to lessen the effects, for instance, on a 15-amp circuit, you would normally use 14-gauge wire to supply the circuit.imothy Thiele. When considering the appropriate wire size for a circuit, don't forget to take the circuit length into consideration. Electrical wire, no matter what material it is made out of, has a certain resistance to it.