Question

What is the magnetic moment associated with a solenoid?

Answer 1

Hint: Magnetic moment is defined as the magnetic strength or the orientation produced by a magnetic material. Solenoids are considered to be one of the most commonly used electromagnets. In the present time. It comprises a rod which is tightly wrapped coils of wire in a considerable amount.

Complete answer:

Solenoids are considered as one of the most commonly used electromagnets. It consists of tightly wrapped coils of wire. If we increase the number of loops, the magnetic field will also increase inside it. The solenoid behaves like a bar magnet only when the current flows through it.

The current also makes an impact on the strength of the magnetic field. An ideal solenoid has zero outer magnetic fields while has uniform magnetic fields inside it.Magnetic moment can be written as,
$\mu =m\times 2l$
where $m$ is the pole strength and $2l$ is the distance between the two poles.
Magnetic moment due to current carrying solenoid can be written as,
$\mu =m\times A$
where $l$ is the current through the solenoid and $A$ is the area of cross-section.

Note: The solenoid has several current loops within itself. Solenoids possess continuous magnetic field lines. If we cut a solenoid into two pieces, then each piece will behave like a small solenoid with a weak magnetic field. The magnetic field will be the same for both solenoids at axial points. The solenoid is an electromagnet and it will show magnetic properties only when the electric current is passed through it, so the poles of the solenoid can vary.