How to choose a good cable

Look at the surface
The technical engineer said that the insulating outer layer of a regular wire is soft and smooth, with uniform color. Several items on the product certificate are printed on its surface, such as: trademark, model and specification, rated voltage, executive standard, factory name, address, length, inspection, and manufacturing date.
two ⃣ : Look at eccentricity
The technical engineer said that the copper core of a regular wire is generally located in the middle of the wire, and the insulation material is uniformly thick to avoid being broken down by current, which can effectively ensure the safety of electricity use.
The technical engineer said that it is recommended to use flame-retardant series wires for home decoration, and use a lighter to burn the insulation layer. If it is a qualified flame-retardant wire, the flame will automatically extinguish when the lighter leaves the insulation layer, with only a small amount of white smoke; If the flame spreads and releases a large amount of white smoke, it indicates poor flame retardance.
three ⃣ : Observe the color of the copper core
The technical engineer said, "Cut the insulating layer to see if the copper core is bright and if the surface color of the copper wire is darkened or severely oxidized.". You can also rub the copper core on a piece of white paper. If there is black material on the white paper, it indicates that there are many impurities in the copper core.