R
Electrical Resistance
Opposition to current flow, measured in ohms (Ω).
Factors
Resistance increases with length, decreases with larger cross-sectional area, and rises with temperature. R = ρL / A.
In testing
Measured resistances (R1+R2, Zs) are taken at ambient temperature; compare with tabulated maxima corrected for conductor operating temperature (Appendix 3 / GN3 tables).
Key regulations
Appendix 3643.2