Conductors comply with IEC, AS/NZS and BSI standard requirements 2. The conductors of multi-core have different shapes. The single-core is circular. The shape of Multi-core cable with size up to and 35m2 can be circular, semicircular and fan-shaped, the conductor with size over and 50m2 are circular and semicircle. 3. A single core is allowed with size below 16m2. Conductor More than 25m2 are multi strands.