An electron (mass 9×$10^{–31 }$ kg and charge 1.6 ×$10^{–19 }$) moving with speed c/100 (c = speed of light) is injected into a magnetic field B of magnitude 9×$10^{–4 }$T perpendicular to its direction of motion. We wish to apply an uniform electric field E together with the magnetic field so that the electron does not deflect from its path. The (speed of light c = 3×108 m$s^{–1}$)