Answer:
magnetic field strength increases.
Explanation:
No, the solenoid will not attract any magnetic substance if it does not carries a direct electric current.
The formula for the magnetic field strength of the solenoid is given as:
[tex]B=\mu.n.I[/tex]
where:
[tex]\mu=[/tex] permeability of free space
[tex]n=[/tex] no. of coil turns in the solenoid
[tex]I=[/tex] current in the coil
So, when the current & no. of coil turns in the coil are increased then the magnetic field strength also increases.