A long, hollow, cylindrical conductor (with inner radius 2.0 mm and outer radius 4.0 mm) carries a current of 24 A distributed uniformly across its cross section. A long thin wire that is coaxial with the cylinder carries a current of 24 A in the opposite direction. What is the magnitude of the magnetic field (a) 1.0 mm, (b) 3.0 mm, and (c) 5.0 mm from the central axis of the wire and cylinder

a) 0.0048 T

b) 0.00093 T

c) 0 T

Explanation:

B = μ(0) [I - i'] / 2πr

where I = 24, and i' = 0, this means that

B = [12.568*10^-7 (24 - 0) ] / 2 * 3.142 * 0.001

B = 3.016*10^-5 / 0.006284

B = 0.0048 T

b), formula is the same, except for change in values, so we have

I = 24, and

i' = (3y2 - 2y2) / (4y2 - 2y2) * 24

i' = 10, and substituting these in the equation, we have

B = [12.568*10^-7 (24 - 10) ] / 2 * 3.142 * 0.003

B = (12.568*10^-7 * 14) / 0.018852

B = 1.76*10^-5 / 0.018852

B = 0.00093 T

and for the last one, we have

I = 24 and i' = 24 also, so that

B = [12.568*10^-7 (24 - 24) ] / 2 * 3.142 * 0.005

B = 0 / 0.03142

B = 0

potential energy is directly proportional to height.

more height = more potential energy.

greatest increase in height = greatest increase in potential energy

where are the points with the greatest increase in height ?

has to be c-e or d-e .

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