Along wire is known to have a radius greater than 10.0 mm and less 20 mm, carry a current uniformly distributed over its cross section. if the magnitude of the magnetic field is 3 mt at a point 6.0 mm from the axis of the wire and 1.50 mt at a point 20 mm from the axis, what is the radius of the wire?

Radius = 7.75 mm

Explanation:

magnetic field inside a point in the wire is given as

now we have

now outside wire magnetic field is given as

now we have

now divide above two equations

because it says use -2,0,and 2 for x, we can plug those numbers into the equation. y/4=3/4(-2)+2   y/4= -1 1/2 +2 now to get x by itself, we can multiply each side by 4. y=-6+8 which equals y=2 when x=-2. now you can do the same thing with 0 and 2 as x. you get y=8 when x=0 and y=14 when x=2.

x   |   y

-2 |   2

0   |   8

2   |   14

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 .