Electricity and magnetism are separate yet interconnected phenomena. Which of the following options does BEST support the idea that electricity and magnetism are interconnected? (A) Electricity is the phenomenon of electric charges, whether they are stopped or moving.
(B) When a particle is stationary or stopped, it has an electric field, yet if the charge is moving, it also generates a magnetic field.
{C) Any magnetic particle or object has a "north" and "south" pole, with the directions based on the orientation of the Earth's magnetic field.
(D) Magnetism, like electricity, also has associated units of measurement, such as Tesla (T).

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

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y