Question

what is a solenoid? write three important feature of this magnetic field

Answer 1

a cylindrical coil of wire acting as a magnet when carrying electric current.
Magnetic lines of force have a number of important properties, which include:

They seek the path of least resistance between opposite magnetic poles. ...

They never cross one another.

They all have the same strength.

Answer 2

solenoid is a cylindrical coil wire acting as a magnet and carrying electric current..........
Important features of solenoid are that they are used in hotel door locks, water pressure valves, MRI machines, hard drives, a speaker etc...........