induction coil

what will be the characteristics( particularly magnetic induction properties) of a coil made into nested solenoids??

nested solenoids: something which i have vizualised, but i dont think it has been made.

its like this:

1) take an extremely long wire, and make it into a solenoid(with a small area, so you have a large number of turns).

2) make it into another solenoid... say, if the length of the solenoid is 200 cms, make it again into a solenoid, with each turn's circumference as 2 cms, so that each turn will also approximately be a toroid(an incomplete toroid).

3) keep repaeating the process till you have many nested solenoids.

A solenoid is a long coil of wire wrapped in many turns. When a current passes through it, it creates a nearly uniform magnetic field inside.
Solenoids can convert electric current to mechanical action, and so are very commonly used as switches.
The magnetic field within a solenoid depends upon the current and density of turns.
In order to estimate roughly the force with which a solenoid pulls on ferromagnetic rods placed near it, one can use the change in magnetic field energy as the rod is inserted into the solenoid. The force is roughly
change in magnetic field energy force on rod = -------------------------------- distance rod moves into solenoid
The energy density of the magnetic field depends on the strength of the field, squared, and also upon the magnetic permeability of the material it fills. Iron has a much, much larger permeability than a vacuum.
Even small solenoids can exert forces of a few newtons.