EM: air core vs solid core

[copperRobot]

Hey everyone, im in need of some help..

i would like some advice on air core electromagnets compaired to solid core. if a solid core EM is 1 1/4 tall and has 10 layers of 24 gauge insulated copper wire, then what size air core EM would compare to its strength using the same power supply 1.5amp and same voltage around 9volts..

 

this magnet has to work constantly for hour aswell.

thanks for any info

[Enthalpy]

Without a core, the electromagnet won't work at all for being too inefficient. Even if huge - which isn't an allmighty solution.