I'm stucked on a practical in which I was supposed to find out how the magnetic force on a current carrying conductor depends on its length, current through it and the magentic field strength. After this I was supposed to plot 3 graphs. Well, I carried out the expt. using a current balance but when I conducted the expt, which had 3 different parts, I got -ve values for (F1 - F0), which is proportional to the force exerted. NB. F1 is the weight of the magnet assembly with current flowing and obviously F0 is the weight without current flowing. Did I get negative values for force because the direction of the magnetic field was reversed? Also, If I use the -ve values, wouldn't my results obtained from the graphs be incorrect? NB. Also, I had to find out what F was by combining the 3 different parts. I.e, I had to find F in terms of I, n (no. of magnets), L and K (constant of proportionality), which I found to be F = KnIL. Thanks for any help.