cybercriminals may place microcomputers in iPhone cables, but there’s nothing inherently malevolent about a ferrite bead. In fact, they are immensely beneficial.
You can refer to that plastic cylinder as a ferrite bead, ferrite choke, EMI filter, ferrite core, or ferrite block. No matter what term you use, the cylinder still fulfills the same function, which is to obstruct radio-frequency interference (RFI) and electromagnetic interference (EMI) in cables and electronic devices. Ferrite consists of iron oxide, and its magnetic ceramic composition guarantees that no disruptive noise is emitted from or into devices. While a ferrite bead can be integrated into smaller cables, larger cables generally feature that recognizable cylinder.
Whether it’s your monitor’s power cord or an older USB cable, that small plastic gadget is assisting you in avoiding problems. Without enrolling you in a basic engineering class, let’s simplify our understanding of this useful material.