# Blog

## What is the magnetic field at the center of the loop? ## How do you find the magnetic dipole moment of a loop?

• θ 3 R where μ=iA is the magnetic dipole moment of the loop sin B = μ ⎪ ⎩ θ 0 4 π R 3 Here i is the current in the loop, A is the loop area, R is the radial distance from the center of the loop, and θ is the polar angle from the Z-axis. The field is equivalent to that from a tiny bar magnet (a magnetic dipole).

## What happens when you put two loops of magnets together?

• If you bring two current-carrying loops close together they will attract or repel one another, juust as bar magnets do. Magnetic Field from Two Loops A set of Helmholtz coils consists of two identical multi-turn coils placed close to one another.

## What happens to electric current in a circular loop?

• Electric current in a circular loop creates a magnetic field which is more concentrated in the center of the loop than outside the loop. Stacking multiple loops concentrates the field even more into what is called a solenoid.  