Which statement about ferrite rings or beads is true?

• A. They reduce radio frequency interference
• B. They increase current in a circuit
• C. They store energy like a capacitor
• D. They decrease the resistance of a conductor

Answer: (A)

Ferrite rings or beads suppress high-frequency noise by presenting high impedance to RF currents. They act as a passive RF choke, converting troublesome fast-changing currents into heat within the ferrite material and thereby reducing radio frequency interference that travels along conductors. This effect is frequency-dependent, so the bead mainly influences signals at RF while leaving DC and low-frequency signals largely unchanged. They are not energy storage devices like capacitors, and they don’t reduce the conductor’s resistance; instead, they add impedance that typically increases with frequency, dampening unwanted high-frequency noise.