We are presently living in a world where charging and eating are almost equal to each other. We can’t survive without them.
Charger is the main component for any electronic device whether it may be a costly DSLR or a budget smartphone. Most of the chargers are straight forward i.e they do not have any bulges or bumps of the wire. But there are some chargers which have a blob at the connecting end of the cord. Mostly these chargers belong to laptops, printers, and digital cameras.
Most of us think that it is useless but the people who are closely associated with the technology might know the importance of it.
Here is the importance of it:
They are known as ferrite beads or ferrite chokes and contains Ferrite (semi-magnetic substance) made from rust (iron oxide) alloyed with other metals. It is nothing but an inductor which is used to suppress/block high-frequency noise in electronic circuits.
The ferrite bead is a passive electronic device which helps to isolate a laptop from electromagnetic noise from the waves which are picked from the existing AC-DC converter or picked up by the wire. Although it is not useful in everyday usage it helps the laptop to pass FCC tests. They are small and least expensive type of interference filters to install on an electronic charging cable.