Notam
pt. otel: L1=2m; S1=0,48mm²=0,48×10⁻⁶m² ; ρ1=10⁻⁷Ωm
pt nichelina L2=1m ; S2=0,21mm²=0,21×10⁻⁶m²; ρ2=5×10⁻⁷Ωm
Calculam rezistenta electrica a fecarei bucati de conductor:
R1=ρ1×L1/S1=10⁻⁷×2/0,48×10⁻⁶=0,416Ω
R2=ρ2×L2/S2=5×10⁻⁷×1/0,21×10⁻⁶=2,38Ω
Rezistenta echivalenta a celor doi conductori inseriati :
R=R1+R2=2,796Ω
Din Legea lui Ohm:
U=R×I Unde I=0,6A
U=2,796×0,6=1,68V