| MadSci Network: Engineering |
Yes it is likely that the cord will "blow apart" at the location of a knot. No it is not likely that this will protect any device connected to the cord.
When a wire conducts a large current of electricity it gets hot, and if the current is large enough, it will melt. If a cord is knotted, that bit will get a bit hotter than the rest because there is more heat released in a small volume, and it can not dissipate so easily. So that is likely to be the first bit to melt. But it will not do so before most of the electrical surge has already reached and damaged the appliance.
There are available, at least in this country, surge protection devices which plug in to the wall socket (and the power lead then plugs into the surge protector). These are designed to cut off the power very quickly if there is a surge, and protect sensitive equipment quite effectively. I do not know if they are good enough to deal with a direct lightning strike.
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