Two cables of copper are of equal length. One of them has a single wire of cross-sectional area A, while the other has 10 wires of cross-sectional area A/(10) each. Give their suitability for transporting ac and dc.

Question

Accepted Answer

(1) only multiple strands for ac, either for dc. At high frequency an alternating current crowds into the outer layer of a conductor, the skin effect, so the middle of a thick single wire carries almost nothing and the useful area is less than A. Splitting the same copper into ten thin strands gives far more surface for the same total area, so the stranded cable is the one to use for ac. A direct current has no skin effect and spreads uniformly, so for dc the two cables have the same resistance and either will do.

Two cables of copper are of equal length. One of them has a single wire of cross-sectional area A, while the other has 10 wires of cross-sectional area A/(10) each. Give their suitability for transporting ac and dc.

Step-by-step solution

Why the other options are wrong