At 01:52 PM 8/17/2012, Brent Weide wrote:
>extension cord (typically has 3 shielded wires inside an external

"Shielded" in electrical context means shielded against interference
by interposing a conducting shield (a tubular one in the case of a
wire).  I suspect you mean "insulated" instead (though I think some
computer-type power cords may indeed have electrical shielding).

Yrs,
d