What is the shape of the magnetic field lines inside a solenoid?

It is established that an electric current through a metallic conductor produces a magnetic field around it. Is there a similar magnetic field produced around a thin beam of moving $(i)$ alpha particles,$(ii)$ neutrons? Justify your answer.

Mention the special feature regarding the shape of magnetic field lines.

What are magnetic field lines? How is the direction of magnetic field at a point determined? Mention two important properties of magnetic field lines.

Choose the correct option.
The magnetic field inside a long straight solenoid carrying current

Identify the poles of the magnet in the given figure.