Hela proton having an initial velvocity of 20.0i Mm/s enters a the swiform magnetic field of magnitude 0.300 T with a direc-
si in perpendicular to the proton's velocity. It leaves the
This field-filled region with velocity -20.0j Mm/s. Determine
ed (a) the direction of the magnetic field, (b) the radius of
curvature of the proton's path while in the field, (c) the
distance the proton traveled in the field, and (d) the time
interval during which the proton is in the field.

the answer is b i think

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

answerscientific theory;