Why do batteries have a potential difference or voltage? * there is an imbalance of electrons at each terminal of the battery

the number of electrons at each terminal of the battery is the same

there is an imbalance of neutrons at each terminal of the battery

the number of neutrons at each terminal of the battery is the same

Basically it all comes down to potential energy. A battery supplies electrical potential energy that can enable electrical current to flow. ... When the battery is connected to a closed circuit, current will flow. The current will encounter electrical resistance causing voltage to drop (a loss in potential energy).

conduction, convection, radiation

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