Quote:

resistance is all about cross-sectional area of the cable

Sort of correct but stranded cable has more surface area for the electrons to flow on - so it has benefits of being lighter, flexible and stronger and it will carry the same amp rating as solid piece of wire of the same gauge and material - that applies to pretty much to low voltage dc and ac circuits.



So what I was taught that in AC current flows on the surface of the conductor, and DC flows inside is wrong, or is there some threshold voltage regarding low voltage DC that I am unaware of? And the the more surface area for stranded is obvious, but not in agreement it applies here.

I'll leave the "stronger" by being stranded alone since it really isn't the key issue here.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.