After a wire has been stripped off the insulating layer, there are a number of thin copper wires inside. Is this a single core or multicore cable? Are these copper wires insulated from each other?
The cost of multi-core cable is lower than that of single core cable; there must be enough bending space in actual construction.Heavy current or high load should be fixed by hard cable, mainly based on overload resistance.Flexible cables are for mobile purposes only.
The power frequency current skin effect is not obvious, so there is no such thing as "better flexibility of multi-core cable than single core cable"!
AC three-phase balance requires multi-core cable, single core armoured cable only for direct current circuit.Even if the cross-sectional area of the single core, carrying capacity is not the same, because of better heat dissipation of single core cable, so the carrying capacity is slightly larger than that of multi core cable.
