Can anyone tell me how to determine the minimum resistance a battery needs to stop it from shorting? for example I'm making an electro magnet, with a 1.5v dc battery cell, but when i turn it on it just drains the battery.
Thanks for these suggestions! ill change the setup shortly, and let you know how it went! Btw, can the coils overlap or does this effect the magnetic field?
I'm making a solenoid electromagnet for gcse demonstration purposes and I'm trying to get a strong:muscle:, clear magnetic effect. I'v wrapped about 100 turns of enamel plated copper wire around a 4" bolt and also a 4" ferrite rod, and am applying 9v DC from a pp3 battery cell.
In both cases...