Answer:
243 N
Explanation:
The formula for electromagnetic force is F= Kq1q2/r^2
where r is the distance between the charges, if the distance between the charges is reduced by 1/3 then F will increase by 9 [(1/3r)^2 becomes 1/9r which is 9F] so 27*9 is 243N
Observe that the given vector field is a gradient field:
Let
, so that



Integrating the first equation with respect to
, we get

Differentiating this with respect to
gives

Now differentiating
with respect to
gives

Putting everything together, we find a scalar potential function whose gradient is
,

It follows that the curl of
is 0 (i.e. the zero vector).
Answer:
A group of atoms where the magnetic fields of the atoms point in the same direction is a magnetic domain.
Explanation:
- In every magnet's magnetic field there is a region where the magnetization is in the same direction. This region is known as magnetic domain.
- In the magnetic domain the atoms always points in the same magnetic filed direction.
- All the atom's magnetic field align in one particular direction.
- This region where atoms align is called as domains.