The flux of the electric field (24 space N divided by C )i with hat on top space plus space (30 space N divided by C )j with hat on top space plus space (16 space N divided by C )k with hat on top spacethrough a 2.0 m2 portion of the yz plane is: A. 23 N/C B. 92 N/C C. 48 N/C D. 140 N/C

 Ф = 28  

Explanation:

The electric field in a region of space is equal to

       E = (24 i + 30 j + 16 k)  N/C

indicate that we want to calculate the flow through a surface of A = 2 m² in the yz plane, therefore this area is defined by its modulus and the normal vector

        A = 2 i

flow is the field through the plane

       Ф = E . A

we calculate

      Ф = (24 i + 30 j + 16 k). 2 i

let's remember that

       i.i = 1

       i.j = i.k = 0

      Ф = 28  

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