I am working on a experiment on finding the Earth's magnetic field strength. Using a Galvanometer and a constant power source of 5.1V and slowly adjusting the resistance, I was able to find the changes in angle in relation to the changes of current.
Then I used the equation to find the $B_H$, the horizontal component BH of the Earth's magnetic field.
However, my calculation shows my $B_H$ is 5.62E-04, while the actual $B_H$ is 5.03E-05. There is a difference of factor of 10!!!