# Calculating the strength of a magnetic field in a electromagnet

hi all,

i have just signed up to this site to find some assistance with the above topic.

i am building an electromagnetic propagator to study the effects of varying field strengths on the germination of seeds and the rooting of cuttings.

it has been many years since i last look into such a topic, and i need some help with my calculations.

would someone be kind enough to give me the formula for calculating the field strength produced by an electro magnet (this is my variable). i am only using the simplist of apparatus i.e. an iron core, insulated copper wire, a transformer (this experiment is for 12v only) and sodium lamps.

Ben

mfb
Mentor
Field strength where? In general, that is a hard problem to analyze in theory.

well, the electromagnet will be placed immediately under the seeds and/or cuttings. So the distance between the magnet and the sample will be no more than 15mm
I had hoped that there would be a formula to calculate the strength of the field using the current, length of wire and the number of turns , in addition to the size of core
it is possible that this may not be as easy as i had first thought, but i am keen to run the experiment in this manner as it provides the ability to alter the field strength over a number of different experiments run at the same time
Thanks

mfb
Mentor
This thread might be interesting, together with some formulas for electromagnets with a core.

sophiecentaur