Ferrite Bead Click to see full answer. In this regard, why laptop charger has a small cylinder?The ferrite bead is used to prevent electromagnetic interference (EMI) to a device or from a device. The cylinder also reduces radio frequency interference (RFI). The reason behind preventing the signals is to stop them from interfering with other electronic devices nearby.Also, can you charge a laptop with any charger? The short answer is; No. You should never intentionally use another laptop’s charger on your laptop. It doesn’t matter if you’re in a pinch or if your battery is about to die. Plugging a different charger that isn’t meant for your specific model will not lead to anything good. Also asked, what is the cylinder in laptop charger? The cylinder has Ferrite, which is an alloy of Iron oxide or rust. This ferrite bead kills signals that the charging cable airs or catches. It is a simple and cheap way of keeping your laptop from interfering with other electronic devices in your home.How do I find out what charger my laptop needs? Choosing a Replacement Adapter: Find your laptop’s model number. You may find this number located on a sticker on the bottom or side of your laptop computer. Find your wattage requirements. Find a compatible laptop adapter.