What is frequency vibration?

 Frequency is the rate of vibration and oscillation measured over a specific period of time (usually one second). In layman's terms, it's simply a repeating sequence.

Explanation:

Frequency, which is measured in hertz (Hz) units, is the rate at which vibrations and oscillations occur. Frequencies are used to determine and differentiate vibrational patterns. So, an atom that is vibrating at a faster rate would be considered a higher frequency than one that is vibrating at a much slower rate.

iron would move it is magnetic there is a mag field around the current in the wire

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia