Along, straight wire with 2 a current flowing through it produces magnetic field strength 1 t at its surface. if the wire has a radius r, where within the wire is the field strength equal to 84 % of the field strength at the surface of the wire? assume that the current density is uniform throughout the wire. (μ 0 = 4π × 10-7 t · m/a)

Explanation:

As per Ampere's law of magnetic field we know that

line integral of magnetic field along closed ampere's loop is equal to the product of current enclosed and magnetic permeability of medium

So it is given as

here we can say that enclosed current is given as

now from ampere'e loop law for any point inside the wire we will have

now we know that magnetic field inside the wire is 84% of the field at its surface

so we will have

so we have

now we know

here i = 2 A

so now we have

the answer would most likely be c, because if it's a comical piece of information, it may likely not be true, if it's a site that allows anybody to edit the content, it could mean a five year old is typing the info, and if it's a tv show produced by a celeb, it may have a biased opinion.

the total distance that martina travels that day is

(distance from home to mom's office) plus (distance from mom's office to school)

plus (distance from school to library) plus (distance from library to friend's house)

plus (distance from friend's house to martina's house).

(we don't know what any of these distance actually is.)