Hello,

What is the usage of a solenoid?
How does it works?
What is Pull and thrust? And how do we see the graph: force vs stroke?
What is the graph trying to tell us?
Pls advise.
Thanks so much.

 

What is the usage of a solenoid?
It converts electrial energy to a mechanical energy, such as pulling or pushing a lever when a switch is closed.

How does it works?
An electric current in a coil attracts an iron plunger into its centre.

What is Pull and thrust?
Look these words up in your dictionary.

And how do we see the graph: force vs stroke?
One looks at it ???

What is the graph trying to tell us?
The force vs stroke relationship.

You should get hold of a book about basic electricity. If this question was prompted by your school homework your school should have one, else, try your library.
Klaus