Assuming that the current is 1A and radius of the circular path of the electron is 4.9

What is the magnetic field where the electrons are traveling that results from this 1 A current in the Helmholtz coils? Hint: Evaluate the expression given for the field betwee two Helmholtz coils with the dimensions used in the experiment.

Provide a numerical answer with no units, simply the field in "microtesla", that is in 10^-6 T. For example, if you found 3.4 x 10^-4 T, answer "340".