Thanks for the reply. Your suggestion about the gravitational force being negligible is true I think, so that answered that question. However I altered the equation to find velocity of the electron if the magnetic field strength was the same as the surface magnetic field strength of the Earth...
I've been given a question to find the magnetic flux density of the Earth if an electron is orbiting near to the surface. The answer to the question makes the magnetic force equal to the centripetal force and solves for B from there.
However, I am confused to why the gravitational force has no...