Ferrite bead are using widely in many product. But it look like a small value inductor with ferrit core. What different between they. Could I replace ferrite bead by inductor. Pls explain this.
Yes, it's different than a inductor, and it could be used as an inductor sometimes.
A ferrite bead would act like a resistor at high frequencies, and it has only ferrite, and no coils.
The ferrite beads use more lossy materials than the inductors.
If you have a RLC bridge, you can find that the inductors span around a Q odf 50 minimum, instead the ferrite beads have a Q about 2 - 10 ( meaning that the resistive part is higher ).