A certain electron-beam lithography tool uses a magnetic field to deflect the beam to draw patterns on a mask. The electron gun uses an extraction electrode voltage of 25 kV. What is the magnitude of a uniform magnetic field required to deflect the electron by a distance of 1cm at the mask surface? Assume the distance between the electron gun and the mask is 0.5m, and the magnetic field is uniform and exists over a region immediately adjacent to the gun exit and over a distance of 0.1m